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Acute and short-term efficacy of sauna treatment on cardiovascular function A meta-analysis

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Abstract

Objective: The role of sauna bathing in cardiovascular function treatment has been increasingly explored, but insufficient attention has been paid to its efficacy. We performed a meta-analysis to provide more evidence for the efficacy of sauna treatment in cardiovascular nursing. Methods: Sixteen peer-reviewed journal articles were screened to summarize the efficacy of the sauna on cardiovascular function. Both acute (0–30 min after the sauna) and short-term (2–4 weeks following the sauna treatment) efficacies were investigated. Results: For pooled acute efficacy, body temperature and heart rate significantly (p<0.001) grew by 0.94℃ and 17.86 beats/min, respectively; reductions of 5.55 mmHg (p<0.001) and 6.50 mmHg (p<0.001) were also observed in systolic blood pressure and diastole blood pressure, respectively. For combined short-term efficacy, left ventricular ejection fraction (LVEF), 6-min walk distance, and flow-mediated dilation (p<0.001) increased by 3.27%, 48.11 m, and 1.71%, respectively; greater amelioration in LVEF was observed in participants with lower LVEF. The proportion of patients with New York Heart Association class III and IV decreased by 10.9% and 12.2%, respectively. Systolic blood pressure, diastolic blood pressure, brain natriuretic peptide concentration, left ventricular end-diastolic dimension, cardiothoracic ratio, and left atrial dimension reduced by 5.26 mmHg (p<0.001), 4.14 mmHg (p<0.001), 116.66 pg/mL (p<0.001), 2.79 mm (p<0.001), 2.628% (p<0.05), and 1.88 mm (p<0.05), respectively, while the concentration of norepinephrine in the plasma remained unchanged. Conclusion: Sauna treatment was found to play a positive role in improving cardiovascular function and physical activity levels, especially in patients with low cardiovascular function. These findings reveal that thermal intervention may be a promising means for cardiovascular nursing.

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... Additionally, a previous study concluded that repeated increase in blood flow caused by heat enhances endothelium-mediated vasodilator function among healthy subjects [8] . SB may also mitigate nonvascular conditions such as obstructive lung disease [9] , the effects of low levels of physical activity [10] , dementia [11] , headaches [12] , mild depression [13] , and adverse skin conditions [14] . Furthermore, existing studies also focused on the biochemical markers including insulin sensitivity [15] , , lower limbs (f), and buttocks (g) is supplied by the common carotid artery (CCA), subclavian artery II (SA II), intercostal arteries (IAs), superior and inferior epigastric artery (SEA and IEA), lumbar artery (LA), femoral artery (FA), and internal iliac artery II (IIA II), respectively. ...
... The proposed model shows a significant increase in cardiac output with the reduction in peripheral resistance, as observed in previous studies [ 58 , 59 ]. This response may be indicative of a reduction in cardiac afterload, which may contribute to the decrease of brain natriuretic peptide concentration in the plasma at a later stage as found by Zhongyou et al. [10] , potentially implying a lower risk of heart failure. Therefore, thermal therapies, such as SB, are promising for mitigating complications (e.g., heart failure) in patients suffering from cardiac ejection insufficiency by relieving cardiac afterload. ...
Article
Objective : Sauna bathing (SB) is an important strategy in cardiovascular protection, but there is no mathematical explanation for the reallocation of blood circulation during heat-induced superficial vasodilation. We sought to reveal such reallocation via a simulated hemodynamic model. Methods : A closed-loop cardiovascular model with a series of electrical parameters was constructed. The body surface was divided into seven blocks and each block was modeled by a lumped resistance. These resistances were adjusted to increase skin blood flow (SBF), with the aim of reflecting heat-induced vasodilation during SB. Finally, the blood pressure was compared before and after SB, and the blood flow inside the aorta and visceral arteries were also analyzed. Results : With increasing SBF in this model, the systolic, diastolic, and mean blood pressure in the arterial trunk decreased by 13–29, 18–36, and 19–37 mmHg, respectively. Despite the increase in the peak and mean blood flow in the arterial trunk, the diastolic blood flow reversal in the thoracic and abdominal aortas increased significantly. Nevertheless, the blood supply to the heart, liver, stomach, spleen, kidney, and intestine decreased by at least 25%. Moreover, the pulmonary blood flow increased significantly. Conclusion : Simulated heat-induced cutaneous vasodilation in this model lowers blood pressure, induces visceral ischemia, and promotes pulmonary circulation, suggesting that the present closed-loop model may be able to describe the effect of sauna bathing on blood circulation. However, the increase of retrograde flow in the aortas found in this model deserves further examination.
... In a meta-analysis of the effects of sauna use on people with heart failure or other cardiovascular disease, it was shown that immediately after leaving the sauna, participants experienced a statistically significant decrease in SBP, DBP, an increase in HR. In the longer term, after one month, an increase in left ventricular ejection fraction, a persistent decrease in 6 SBP and DBP, a decrease in BNP and, very importantly, patients achieved clinical improvements in exercise tolerance were noted [20]. ...
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Introduction: As a popular way to relax, the sauna is used by many people. The safety of sauna use and the possible benefits of sauna attendance are the subject of scientific research. One of the most studied aspects is the impact and safety assessment of sauna use on people with cardiovascular diseases. In addition to the effects of the traditional Finnish sauna, the effectiveness of Waon therapy, which is a type of dry infrared sauna that was invented for the treatment of people with cardiovascular diseases, was analysed. Aim of the study: Analysis of the available scientific research on the effects of traditional Finnish sauna and infrared sauna (so-called Waon) on the cardiovascular system in healthy people and those with cardiovascular diseases such as heart failure, coronary heart disease, hypertension. Methods: Review of the literature available in PubMed, Google Scholar and Cochrane Library databases by searching with keywords such as ‘sauna’, ‘Finnish bath’, ‘waon’, ‘waon therapy’ ‘heart failure’, “chronic heart failure”, ’hypertension’ , ‘cardiovascular system’. Conclusion: Conventional Finnish sauna and Waon therapy are interventions with proven positive effects on the cardiovascular system in many studies. The results show that these interventions help to lower blood pressure, improve vascular function, increase myocardial perfusion, induce a reduction in symptoms associated with heart failure and improve exercise tolerance in this patient group. Patients with heart failure are a large group that could potentially benefit from the use of sauna and especially Waon therapy, although there are studies showing that sauna can also protect healthy individuals from future hypertension.
... Sauna bathing is a form of passive heat exposure using a room heated to~70-100 • C and 15-30% relative humidity, usually for a period of 5-20 min [65]. While previous systematic and literature reviews have considered the effect of sauna bathing on cardiovascular and health parameters (e.g., blood pressure and immune function) [65][66][67], to date we are unaware of any systematic reviews or meta-analyses considering the effect of sauna use on athletic recovery following exercise. Sauna bathing following exercise may be used to promote relaxation, increase blood perfusion to the muscle, and improve injury rehabilitation [68,69]. ...
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The sport and athletic performance industry has seen a plethora of new recovery devices and technologies over recent years, and it has become somewhat difficult for athletes, coaches, and practitioners to navigate the efficacy of such devices or whether they are even required at all. With the increase in recovery devices and tools, it has also become commonplace for athletes to overlook more traditional, well-established recovery strategies. In this narrative review, we discuss recovery strategies in relation to the hierarchy of scientific evidence, classifying them based on the strength of the evidence, ranging from meta-analyses through to case studies and reports. We report that foam rolling, compression garments, cryotherapy, photobiomodulation, hydrotherapy, and active recovery have a high level of positive evidence for improved recovery outcomes, while sauna, recovery boots/sleeves, occlusion cuffs, and massage guns currently have a lower level of evidence and mixed results for their efficacy. Finally, we provide guidance for practitioners when deciding on recovery strategies to use with athletes during different phases of the season.
... The most common of these approaches are heat-based interventions that aim to induce a significant elevation in core temperature, which have subsequently shown the potential to drive adaptive improvements in endothelial function (Cheng and MacDonald 2018). As a result of increases in cardiac output and redistribution of blood in response to increases in core temperature, heat-based interventions have been shown to drive significant changes in blood flow, comparable to those seen in exercise, across a range of stimulus types, including hot water bathing , sauna bathing (Li et al. 2020), and the utilisation of water perfused body suits (Chiesa et al. 2016). Similarly, despite a lack of skeletal muscle activation, passive heating interventions have also been shown to drive elevations in a number of vasoactive factors seen to increase during exercise, including IL-6 and HSP72 (Hoekstra et al. 2018). ...
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The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.
... Adaptations of the human body to various forms of heat stress and hyperthermia have been shown to play a positive role in protecting from developing major chronic and degenerative diseases, including cardiovascular, neurodegenerative and metabolic disorders (Iguchi et al., 2012;Laukkanen et al., 2015, Laukkanen et al., 2016Hussain and Cohen, 2018;Ukai et al., 2020;Zhongyou L et al., 2020, Hunt et al., 2020. According to our previous studies on healthy humans, adaptation to 10 weeks of passive hyperthermia sessions is characterised by an increase in aerobic performance and cardiorespiratory endurance, an increase in subjectively reported quality of life and in the level of serum Brain-Derived Neurotrophic Factor (BDNF) (Glazachev et al., 2020a;2020b). ...
Article
Context Hyperthermia is known to be beneficial to patients affected by various diseases. Irisin is a key regulators of fat metabolism known to be released as response to cold. Brain Derived Neurotrophic Factor (BDNF) is a marker of neuroplasticity usually increased as response to acute exposure to human body stressors. Objective Effect of a repeated hyperthermia exposure programme on changes in circulating irisin and serum BDNF in healthy humans. Design Setting, Participants: Randomized, single-blind, cross-over trial in healthy humans conducted at Sechenov University Physiology Laboratory from April 2019. The treatment period was 2 weeks (wash-out 3 weeks). Researchers analysing serum biomarkers and questionnaires data were blinded to participants allocation. Participants were 20 healthy male (age 21.5 ± 2.1 years). Intervention Hyperthermia exposure programme (WBPH) versus sham exposure (SHAM) to hyperthermia (10 sessions in two weeks). Main outcome measure Changes in irisin and BDNF before and after short hyperthermia exposure. Results Twenty participants were analysed. Irisin increased significantly in group WBPH only: 6.3 μg/ml (mean with SD = 1.6) compared to 5.4 μg/ml (SD = 1.7) in SHAM group; This value was also higher than baseline (5.0 mean with SD = 1.1) in WBPH. After 10 sessions mean change in BDNF was higher in WBPH group vs SHAM: BDNF was 28,263 (SD = 4213) pg/ml in WBPH group and 24,064 (SD = 5600) pg/ml in SHAM group. BDNF concentrations were significantly higher than baseline values in WBPH group only, 28,263 (SD 4213) vs 25,888 (SD 4316) pg/ml. Conclusion In healthy young humans a 2-week, ten sessions programme consisting of repeated exposure to hyperthermia resulted in a significantly higher increase of circulating Irisin and BDNF. Free full text download until December 1, 2021 https://authors.elsevier.com/c/1dvIX15hXu4irr
... 7,11 Several studies in hypertensive and heart failure patients have shown that frequent, short-term exposure to high levels of environmental heat (eg, sauna baths) is a relatively safe intervention that may be associated with reduced cardiovascular risk and improved hemodynamic function, including BP reduction. 43,44 These observations, however, cannot be extrapolated to our study population given the unique clinical characteristics of autonomic failure. In addition, our study has some limitations that should be considered before recommending local heat as a therapeutic option but at the same time open opportunities for further research. ...
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Aim To determine the cardiovascular effects of sauna bath on heart failure patients. Methods and results PubMed, Cochrane Library and CINAHL databases were searched to identify randomized and non‐randomized controlled studies to compare effects of sauna bath with no sauna bath. Studies were searched for both infrared sauna bath and Finnish sauna bath. The strength of evidence was rated using a modified GRADE approach. Out of 1,444 studies, nine met the inclusion criteria and were included in this review. Seven of these nine studies were included in the meta‐analysis, which included a total of 491 patients with heart failure (>95% in New York Health Association (NYHA) class II‐III), and with mean ejection fraction of <40% at baseline. Only studies with infrared sauna bath met the inclusion criteria. In the meta‐analysis, exposure to an infrared sauna bath in 60° C for 15 minutes, followed by a 30‐minute rest in warm environment, 5 times a week for 2‐4 weeks, was associated with a significant reduction in B‐type natriuretic peptide (BNP), cardiothoracic ratio (CTR) and an improvement in left ventricular ejection fraction (EF). There was no significant effect on left ventricular end‐diastolic diameter, left atrial diameter, systolic blood pressure or diastolic blood pressure. The strength of evidence varied from moderate to insufficient. Conclusion Infrared sauna bath was associated with short‐term improvement in cardiac function. More evidence is needed about long‐term effects of sauna bath and the effects of a Finnish sauna on cardiovascular health among patients with heart failure or other cardiovascular diseases.
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Emerging evidence suggests beneficial effects of sauna bathing on the cardiovascular system. However, the effects of sauna bathing on parameters of cardiovascular function and blood-based biomarkers are uncertain. We aimed to investigate whether sauna bathing induces changes in arterial stiffness, blood pressure (BP), and several blood-based biomarkers. We conducted an experimental study including 102 participants (mean age (SD): 51.9 (9.2) years, 56% male) who had at least one cardiovascular risk factor. Participants were exposed to a single sauna session (duration: 30 min; temperature: 73 °C; humidity: 10-20%). Cardiovascular as well as blood-based parameters were collected before, immediately after, and after 30-min recovery. Mean carotid-femoral pulse wave velocity was 9.8 (2.4) m/s before sauna and decreased to 8.6 (1.6) m/s immediately after sauna (p < 0.0001). Mean systolic BP decreased after sauna exposure from 137 (16) to 130 (14) mmHg (p < 0.0001) and diastolic BP from 82 (10) to 75 (9) mmHg (p < 0.0001). Systolic BP after 30 min recovery remained lower compared to pre-sauna levels. There were significant changes in hematological variables during sauna bathing. Plasma creatinine levels increased slightly from sauna until recovery period, whereas sodium and potassium levels remained constant. This study demonstrates that sauna bathing for 30 min has beneficial effects on arterial stiffness, BP, and some blood-based biomarkers. These findings may provide new insights underlying the emerging associations between sauna bathing and reduced risk of cardiovascular outcomes.
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Background: Sauna bathing is associated with reduced cardiovascular risk, but the mechanisms underlying this beneficial effect are not entirely understood. We aimed to assess the relationship between sauna bathing and risk of incident hypertension. Methods: Frequency of sauna bathing was ascertained using questionnaires in the Kuopio Ischemic Heart Disease Study, a prospective cohort study conducted in Eastern Finland that comprised a population-based sample of 1,621 men aged 42 to 60 years without hypertension at baseline. The incidence of hypertension was defined as a physician diagnosis of hypertension, systolic blood pressure (SBP) >140 mm Hg, diastolic blood pressure >90 mm Hg, or use of antihypertensive medication. Results: During a median follow-up of 24.7 years, 251 incident cases (15.5%) were recorded. In Cox regression analysis adjusted for baseline age, smoking, body mass index, and SBP; compared to participants reporting 1 sauna session per week, the hazard ratio for incident hypertension in participants reporting 2 to 3 sessions and 4 to 7 sessions was 0.76 (95% confidence interval: 0.57-1.02) and 0.54 (0.32-0.91), respectively. The corresponding hazard ratios were similar after further adjustment for glucose, creatinine, alcohol consumption, heart rate, family history of hypertension, socioeconomic status, and cardiorespiratory fitness: 0.83 (95% confidence interval: 0.59-1.18) and 0.53 (0.28-0.98), respectively. Conclusions: Regular sauna bathing is associated with reduced risk of hypertension, which may be a mechanism underlying the decreased cardiovascular risk associated with sauna use. Further epidemiological and experimental studies could help elucidate the effects of sauna bathing on cardiovascular function.
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Objectives. To study physiological, therapeutic and adverse effects of sauna bathing with special reference to chronic diseases, medication and special situations (pregnancy, children). Study design. A literature review. Methods. Experiments of sauna bathing were accepted if they were conducted in a heated room with sufficient heat (80 to 90 degrees C), comfortable air humidity and adequate ventilation. The sauna exposure for five to 20 minutes was usually repeated one to three times. The experiments were either acute (one day), or conducted over a longer period (several months). Results. The research data retrieved were most often based on uncontrolled research designs with subjects accustomed to bathing since childhood. Sauna was well tolerated and posed no health risks to healthy people from childhood to old age. Baths did not appear to be particularly risky to patients with hypertension, coronary heart disease and congestive heart failure, when they were medicated and in a stable condition. Excepting toxemia cases, no adverse effects of bathing during pregnancy were found, and baths were not teratogenic. In musculoskeletal disorders, baths may relieve pain. Medication in general was of no concern during a bath, apart from antihypertensive medication, which may predispose to orthostatic hypotension after bathing. Conclusions. Further research is needed with sound experimental design, and with subjects not accustomed to sauna, before sauna bathing can routinely be used as a non-pharmacological treatment regimen in certain medical disorders to relieve symptoms and improve wellness.
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Background: Waon therapy improves heart failure (HF) symptoms, but further evidence in patients with advanced HF remains uncertain.Methods and Results:In 19 institutes, we prospectively enrolled hospitalized patients with advanced HF, who had plasma levels of B-type natriuretic peptide (BNP) >500 pg/ml on admission and BNP >300 pg/ml regardless of more than 1 week of medical therapy. Enrolled patients were randomized into Waon therapy or control groups. Waon therapy was performed once daily for 10 days with a far infrared-ray dry sauna maintained at 60℃ for 15 min, followed by bed rest for 30 min covered with a blanket. The primary endpoint was the ratio of BNP before and after treatment. In total, 76 Waon therapy and 73 control patients (mean age 66 years, men 61%, mean plasma BNP 777 pg/ml) were studied. The groups differed only in body mass index and the frequency of diabetes. The plasma BNP, NYHA classification, 6-min walk distance (6MWD), and cardiothoracic ratio significantly improved only in the Waon therapy group. Improvements in NYHA classification, 6MWD, and cardiothoracic ratio were significant in the Waon therapy group, although the change in plasma BNP did not reach statistical significance. No serious adverse events were observed in either group. Conclusions: Waon therapy, a holistic soothing warmth therapy, showed clinical advantages in safety and efficacy among patients with advanced HF.
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Sauna bathing is a health habit associated with better hemodynamic function; however, the association of sauna bathing with cardiovascular and all-cause mortality is not known. To investigate the association of frequency and duration of sauna bathing with the risk of sudden cardiac death (SCD), fatal coronary heart disease (CHD), fatal cardiovascular disease (CVD), and all-cause mortality. We performed a prospective cohort study (Finnish Kuopio Ischemic Heart Disease Risk Factor Study) of a population-based sample of 2315 middle-aged (age range, 42-60 years) men from Eastern Finland. Baseline examinations were conducted from March 1, 1984, through December 31, 1989. Frequency and duration of sauna bathing assessed at baseline. During a median follow-up of 20.7 years (interquartile range, 18.1-22.6 years), 190 SCDs, 281 fatal CHDs, 407 fatal CVDs, and 929 all-cause mortality events occurred. A total of 601, 1513, and 201 participants reported having a sauna bathing session 1 time per week, 2 to 3 times per week, and 4 to 7 times per week, respectively. The numbers (percentages) of SCDs were 61 (10.1%), 119 (7.8%), and 10 (5.0%) in the 3 groups of the frequency of sauna bathing. The respective numbers were 89 (14.9%), 175 (11.5%), and 17 (8.5%) for fatal CHDs; 134 (22.3%), 249 (16.4%), and 24 (12.0%) for fatal CVDs; and 295 (49.1%), 572 (37.8%), and 62 (30.8%) for all-cause mortality events. After adjustment for CVD risk factors, compared with men with 1 sauna bathing session per week, the hazard ratio of SCD was 0.78 (95% CI, 0.57-1.07) for 2 to 3 sauna bathing sessions per week and 0.37 (95% CI, 0.18-0.75) for 4 to 7 sauna bathing sessions per week (P for trend = .005). Similar associations were found with CHD, CVD, and all-cause mortality (P for trend ≤.005). Compared with men having a sauna bathing session of less than 11 minutes, the adjusted hazard ratio for SCD was 0.93 (95% CI, 0.67-1.28) for sauna bathing sessions of 11 to 19 minutes and 0.48 (95% CI, 0.31-0.75) for sessions lasting more than 19 minutes (P for trend = .002); significant inverse associations were also observed for fatal CHDs and fatal CVDs (P for trend ≤.03) but not for all-cause mortality events. Increased frequency of sauna bathing is associated with a reduced risk of SCD, CHD, CVD, and all-cause mortality. Further studies are warranted to establish the potential mechanism that links sauna bathing and cardiovascular health.
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Seasonal associations of cardiovascular mortality have been noted in most populations of European origin years ago, but are not well evaluated in Asian populations recently. Utilizing the electronic Hospitalization Summary Reports (HSRs) from 32 top-ranked hospitals in Beijing, China, we evaluated the association between winter season and the risk of cardiovascular death among hospitalized individuals. General additive models and logistic regression models were adjusted for confounding factors. Older patients who were admitted to the hospital in the winter months (January, February, November and December) had a death risk that was increased by approximately 30% to 50% (P < 0.01) over those who were admitted in May. However, younger patients did not seem to experience the same seasonal variations in death risk. The excess winter deaths among older patients were associated with ischemic heart disease (RR = 1.22; 95% CI 1.13 to 1.31 ), pulmonary heart disease (RR = 1.42; 95% CI 1.10 to 1.83), cardiac arrhythmias (RR = 1.67 ; 95% CI 1.36 to 2.05), heart failure (RR = 1.30 ; 95% CI 1.09 to 1.54), ischemic stroke (RR = 1.30 ; 95% CI 1.17 to 1.43), and other cerebrovascular diseases (RR = 1.78 ; 95% CI 1.40 to 2.25). The risks of mortality were higher in winter months than in the month of May, regardless of the presence or absence of respiratory disease. Winter season was associated with a substantially increased risk of cardiovascular death among older Chinese cardiovascular inpatients.
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Waon therapy has beneficial effects on chronic heart failure (CHF), peripheral arterial disease, and other various diseases. This was to assess the safety and effect of Waon therapy by echocardiography for the first time in Korea. Ten patients with CHF were enrolled. The patients with a light gown were placed in a sitting-position in an evenly maintained 60 dry sauna system for 15 minutes, and then after leaving the sauna, they underwent bed rest with a blanket to keep them warm for an additional 30 minutes. Waon therapy was performed once a day, 5 days a week. Four of the 5 patients who had been treated for more than 2 weeks as protocol noted improvement of heart failure (HF) symptoms and decrease in left ventricular (LV) volume. There were trends in improvement of LV ejection fraction and parameters of diastolic function after the therapy although statistical significance was lack. No one complained of worsening of HF symptoms. In each session, body weight (61.8+/-10.2 kg vs. 61.6+/-10.3 kg, p=0.008) and blood pressure (systolic, 119+/-28 vs. 111+/-27 mmHg, p=0.005; diastolic, 69+/-12 mmHg vs. 63+/-10 mmHg, p=0.005) were significantly decreased, oral temperature (35.9+/-0.4 vs. 37.0+/-0.9, p=0.017) was increased by 1.0 at the end of sauna bathing, but the heart rate (71+/-10/min vs. 72+/-8/min, p=0.8) was not changed. We have experienced Waon therapy which was safe and well tolerated and some beneficial effects for patients with CHF. Large scale randomized study is needed to apply Waon therapy as a promising therapy in Korean HF patients.
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The CONSORT statement is used worldwide to improve the reporting of randomised controlled trials. Kenneth Schulz and colleagues describe the latest version, CONSORT 2010, which updates the reporting guideline based on new methodological evidence and accumulating experience. To encourage dissemination of the CONSORT 2010 Statement, this article is freely accessible on bmj.com and will also be published in the Lancet, Obstetrics and Gynecology, PLoS Medicine, Annals of Internal Medicine, Open Medicine, Journal of Clinical Epidemiology, BMC Medicine, and Trials.
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The aim of this work was to review and provide a summary of published literature on the clinical impact of thermal therapy (ie, warm water immersion, traditional sauna bathing, and dry infrared sauna) in patients with heart failure. Medline and Embase database literature searches were conducted, and studies that included measurement of heart failure-related clinical parameters were reviewed. Thermal therapy was found to have a positive impact on key heart failure-related parameters across multiple studies. Significant improvements were noted across a wide scope of heart failure-related parameters in the areas of (1) endothelial function, (2) hemodynamics, (3) cardiac geometry, (4) neurohormonal markers, and (5) quality of life. Of special note, thermal therapy also conveyed a strong antiarrhythmic effect in heart failure patients. The clinical evidence highlights repeatable and compelling data showing that thermal therapy may provide an important and viable adjunct in the treatment of heart failure.
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Funnel plots (plots of effect estimates against sample size) may be useful to detect bias in meta-analyses that were later contradicted by large trials. We examined whether a simple test of asymmetry of funnel plots predicts discordance of results when meta-analyses are compared to large trials, and we assessed the prevalence of bias in published meta-analyses. Medline search to identify pairs consisting of a meta-analysis and a single large trial (concordance of results was assumed if effects were in the same direction and the meta-analytic estimate was within 30% of the trial); analysis of funnel plots from 37 meta-analyses identified from a hand search of four leading general medicine journals 1993-6 and 38 meta-analyses from the second 1996 issue of the Cochrane Database of Systematic Reviews. Degree of funnel plot asymmetry as measured by the intercept from regression of standard normal deviates against precision. In the eight pairs of meta-analysis and large trial that were identified (five from cardiovascular medicine, one from diabetic medicine, one from geriatric medicine, one from perinatal medicine) there were four concordant and four discordant pairs. In all cases discordance was due to meta-analyses showing larger effects. Funnel plot asymmetry was present in three out of four discordant pairs but in none of concordant pairs. In 14 (38%) journal meta-analyses and 5 (13%) Cochrane reviews, funnel plot asymmetry indicated that there was bias. A simple analysis of funnel plots provides a useful test for the likely presence of bias in meta-analyses, but as the capacity to detect bias will be limited when meta-analyses are based on a limited number of small trials the results from such analyses should be treated with considerable caution.
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We study recently developed nonparametric methods for estimating the number of missing studies that might exist in a meta-analysis and the effect that these studies might have had on its outcome. These are simple rank-based data augmentation techniques, which formalize the use of funnel plots. We show that they provide effective and relatively powerful tests for evaluating the existence of such publication bias. After adjusting for missing studies, we find that the point estimate of the overall effect size is approximately correct and coverage of the effect size confidence intervals is substantially improved, in many cases recovering the nominal confidence levels entirely. We illustrate the trim and fill method on existing meta-analyses of studies in clinical trials and psychometrics.
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Both cardiorespiratory fitness (CRF) and frequency of sauna bathing (FSB) are each strongly and independently associated with sudden cardiac death (SCD) risk. However, the combined effect of CRF and FSB on SCD risk has not been previously investigated. We evaluated the joint impact of CRF and FSB on the risk of SCD in the Kuopio Ischemic Heart Disease prospective cohort study of 2291 men aged 42-61 years at recruitment. Objectively measured CRF and self-reported sauna bathing habits were assessed at baseline. CRF was categorized as low and high (median cutoffs) and FSB as low and high (defined as ≤2 and 3-7 sessions/week respectively). Multivariable adjusted hazard ratios (HRs) with confidence intervals (CIs) were calculated for SCD. During a median follow-up of 26.1 years, 226 SCDs occurred. Comparing high vs low CRF, the HR (95% CIs) for SCD in analysis adjusted for several established risk factors was 0.48 (0.34-0.67). Comparing high vs low FSB, the corresponding HR was 0.67 (0.46-0.98). Compared to men with low CRF & low FSB, the multivariate-adjusted HRs of SCD for the following groups: high CRF & high FSB; high CRF & low FSB; and low CRF & high FSB were 0.31 (0.16-0.63), 0.49 (0.34-0.70), and 0.71 (0.45-1.10) respectively. In a general male Caucasian population, the combined effect of high aerobic fitness (as measured by CRF) and frequent sauna baths is associated with a substantially lowered risk of future SCD compared with high CRF or frequent sauna bathing alone.
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Complementary and alternative treatments have been proposed for heart failure (HF), including Waon therapy, a kind of sauna therapy; however, studies have been shown divergent results. Therefore, the main objective of this study was to perform a systematic review about the effect of sauna therapy on left ventricular ejection fraction (LVEF), blood pressure, natriuretic peptides (NP), and noradrenaline in patients with HF.
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Purpose: We aimed to evaluate the joint impact of cardiorespiratory fitness (CRF) and frequency of sauna bathing (FSB) on the risk of cardiovascular and all-cause mortality. Design: CRF measured by respiratory gas analyses and sauna exposure were assessed at baseline in a prospective study of 2,277 men. CRF was categorized as low and high (median cutoffs) and FSB as low and high (≤ 2 and 3-7 sessions/week respectively). Results: During a median follow-up of 26.1 years, 520 cardiovascular and 1,124 all-cause deaths occurred. Comparing high vs low CRF, the multivariate-adjusted hazard ratios (HRs) 95% CIs for cardiovascular and all-cause mortality were 0.51 (0.41-0.63) and 0.65 (0.57-0.75) respectively. Comparing high vs low FSB, the corresponding HRs were 0.74 (0.59-0.94) and 0.84 (0.72-0.97) respectively. Compared to low CRF & low FSB, the HRs of CVD mortality for high CRF & high FSB; high CRF & low FSB; and low CRF & high FSB were 0.42 (0.28-0.62), 0.50 (0.39-0.63), and 0.72 (0.54-0.97) respectively. For all-cause mortality, the corresponding HRs were 0.60 (0.48-0.76), 0.63 (0.54-0.74), and 0.78 (0.64-0.96) respectively. Conclusion: A combination of high CRF and frequent sauna bathing confers stronger long-term protection on mortality outcomes compared with high CRF or high FSB alone.
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Background: Exercise prescription for patients with cardiovascular disease remains a challenge. The concept of exercising at an intensity equivalent to one's anaerobic threshold has been well studied and highly recommended in the fitness industry for other populations. For this concept to be applicable to patients with cardiovascular disease, the level and intensity of activity must not trigger myocardial ischemia. Hypothesis: We hypothesized that the heart rate at ventilatory anaerobic threshold (HRVAT ) will not exceed heart rate at ischemic threshold (HRIT ) (ie, HRVAT ≤ HRIT in a majority [>50%] of patients). Methods: In this retrospective pilot study, 19 patients, mean age at baseline of 45.0 ± 15.6 years, who had positive cardiopulmonary exercise stress testing were included. Heart rate at ventilatory anaerobic threshold (VAT) was derived from a computer-analyzed V-slope method. The ischemic threshold (IT) was determined from electrocardiogram. The exercise test parameters at VAT in relation to IT were examined. Results: Heart rate at VAT preceded heart rate at IT in 89.5% of patients. On average, achievement of VAT preceded IT relative to workload (119.5 ± 49.6 vs 132.6 ± 47.5; P < 0.01), heart rate (121.2 ± 15.9 vs 133.3 ± 17.5; P < 0.01), oxygen consumption (19.3 ± 4.9 vs 20.8 ± 3.7; P < 0.01), and respiratory exchange ratio (0.96 ± 0.10 vs 1.01 ± 0.07; P < 0.01). Conclusions: Greater than 50% of patients met the criteria of HRVAT ≤ HRIT ; therefore, we propose that anaerobic threshold is a suitable target aerobic exercise heart rate for all patients with cardiovascular diseases indicated for cardiopulmonary rehabilitation.
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Background: Heart failure (HF) is a disease of neurohumoral dysfunction and current pharmacological therapies for HF have not improved mortality rates, thus requiring additional new strategies. Waon therapy for HF patients may be a complementary strategy with peripheral vasodilation via nitric oxide. We hypothesized that Waon therapy would improve neurohumoral factors, such as natriuretic peptides (NP) and the renin-angiotensin-aldosterone system (RAAS) in HF.Methods and Results:Plasma samples were collected from patients enrolled in the WAON-CHF Study (Waon therapy (n=77) or control (n=73)) before and after the treatment. B-type NP (BNP), C-type NP (CNP), and aldosterone (Aldo) levels were measured by respective specific radioimmunoassays. Although clinical parameters significantly improved in the Waon group compared with the control group, BNP, Aldo, and CNP levels were not statistically different between groups. On subanalysis with patient variables, BNP levels were improved in the Waon group treated with angiotensin-converting enzyme inhibitor/angiotensin-receptor blocker or spironolactone. In addition, Aldo levels were improved in the Waon group patients with diabetes mellitus, hypertension, and inotrope use, and CNP levels were improved in Waon group patients with estimated glomerular filtration rate <60 mL/min/1.73 m(2). These changes were not observed in the control group. Conclusions: Waon therapy may accelerate the favorable actions of RAAS modulators in HF. (WAON-CHF Study: UMIN000006705).
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Aims: To investigate the predictors and outcome of acute kidney injury (AKI) after transcatheter aortic valve implantation (TAVI). Methods and results: There were 35 articles recruiting 13,256 patients included in our study. Hypertension (odds ratio [OR], 1.92, 95% CI, 1.44 to 2.56), diabetes mellitus (OR, 1.33, 95% CI, 1.20 to 1.47), peripheral artery disease (OR, 1.28, 95% CI, 1.14 to 1.45), and a left ventricular ejection fraction <40% (OR, 1.50, 95% CI, 1.19 to 1.88) were identified as significant independent predictors of AKI. In addition to the aforementioned comorbidities, procedure-related/post-TAVI factors such as transapical access (OR, 1.68, 95% CI, 1.44 to 1.97), major bleeding (OR, 1.82, 95% CI, 1.37 to 2.40) and transfusion (OR, 1.30, 95% CI, 1.12 to 1.51) were also associated with a higher risk of AKI. Importantly, the risk of short-term all-cause death increased progressively with the aggravating severity of AKI (OR, 30 days: stage 1: 3.41; stage 2: 4.0; stage 3: 11.02; 1 year: stage 1: 1.95; stage 2: 2.82; stage 3: 7.34) as determined via a univariate analysis. After eliminating confounders, AKI remained linked to a higher risk for both short-term (30 days: HR, 2.12, 95% CI, 1.59 to 2.83) and long-term (≥3 years: HR, 1.37, 95% CI, 1.27 to 1.48) all-cause mortality. Conclusions: The reason for the occurrence of AKI was multifactorial including baseline characteristics, procedure-related and post-TAVI factors. And, it appeared that even stage 1 AKI exerted detrimental effects on survival within 1 year, and AKI was also independently linked to mortality beyond 3 years.
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The CONSORT statement is used worldwide to improve the reporting of randomised controlled trials. Kenneth Schulz and colleagues describe the latest version, CONSORT 2010, which updates the reporting guideline based on new methodological evidence and accumulating experience. To encourage dissemination of the CONSORT 2010 Statement, this article is freely accessible on www.ijph.it.
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Waon therapy (WT), which in Japanese means soothing warmth, is a repeated sauna therapy that improves cardiac and vascular endothelial function in patients with chronic heart failure (CHF). We investigated whether WT could improve the quality of life (QOL) of CHF patients in addition to improving cardiac function and exercise capacity. A total of 49 CHF patients (69 ± 14 years old) were treated with a 60°C far infrared-ray dry sauna bath for 15 minutes and then kept in a bed covered with blankets for 30 minutes once a day for 3 weeks. At baseline and 3 weeks after starting WT, cardiac function, 6-minute walk distance (6MWD), flow mediated dilation (FMD) of the brachial artery, and SF36-QOL scores were determined. WT significantly improved left ventricular ejection fraction (LVEF), B-type natriuretic peptide (BNP), 6MWD, and FMD (3.6 ± 2.3 to 5.1 ± 2.8%, P < 0.01). Moreover, WT significantly improved not only the physical (PC) but also mental component (MC) of the QOL scores. WT-induced improvement of PC was negatively correlated with changes in BNP (r = -0.327, P < 0.05), but MC improvement was not related directly to changes in BNP, LVEF, or 6MWD. WT-induced changes in MC were not parallel to PC improvement. WT improved QOL as well as cardiac function and exercise capacity in patients with CHF. Mental QOL improved independently of WT-induced improvement of cardiac function and exercise capacity.
Article
Background: One of the well-established methods used to determine endurance training intensity for patients in outpatient cardiac rehabilitation (CR) is to take a percentage (70%-85%) of the maximal or peak heart rate (HRmax) from a recent postevent symptom-limited graded exercise test (GXT). Because many patients are referred to CR without having had a maximal GXT, a current practice is to use 30% to 50% above resting heart rate (RHR) to estimate endurance training intensity. Objective: The purpose of this study was to determine if a target heart rate (THR) of 30% to 50% above RHR approximated a THR of 70% to 85% of the HRmax achieved on GXT (HRmax GXT) and provided equivalent exercise intensity based on ratings of perceived exertion (RPE) and metabolic equivalency thresholds (METs). Methods: A retrospective chart review of 53 patients enrolled in CR and had documentation of postevent GXT was conducted to determine the patient's mean exercise heart rate (HR) achieved at each session to percentage above RHR and percentage HRmax GXT. Analysis was conducted to determine and compare patients' HRs, RPE, and MET levels when patients were exercising within the THR ranges of 30% to 50% above RHR and 70% to 85% HRmax GXT. Results: A THR range of 30% to 50% above RHR approximated 60% to 70% HRmax GXT. Mean exercise HRs progressed from 39% to 49% above RHR sessions 2 to 6 with mean (SD) RPE of 10.58 (0.55) to 11.44 (0.68) on the Borg scale and mean (SD) MET level of 2.91 (0.55) to 3.31 (0.6). Mean exercise HRs progressed to 54% to 65% above RHR sessions 7 to 18 and approximated 70% to 73% HRmax GXT. Mean (SD) RPE at this intensity ranged from 11.57 (0.58) to 12.21 (0.53) with a mean (SD) MET level of 3.47 (0.6) to 3.8 (0.77). Conclusion: In the observed population, a THR of 30% to 50% above RHR underestimated the THR range of 70% to 85% HRmax GXT but provided adequate exercise intensity for patients at the beginning of a CR program based on percentage HRmax GXT, RPE and MET levels.
Article
The discovery of the endothelium as a crucial organ for the regulation of the vasculature to physiological needs and the recognition of endothelial dysfunction as a key pathological condition - which is associated with most if not all cardiovascular risk factors - led to a tremendous boost of endothelial research in the past 3 decades. Despite the possibility to measure endothelial function in the individual and its widespread use in research, its use as a clinical tool in daily medicine is not established yet. We review the most common methods to assess vascular function in humans and discuss their advantages and disadvantages. Furthermore we give an overview about clinical settings were endothelial function measurements may be valuable in individual patients. Specifically, we provide information why endothelial function is not only a risk marker for cardiovascular risk but may also provides prognostic information beyond commonly used risk scores in primary prevention, and in patients with already established coronary disease. We conclude, that non-invasive endothelial function measurements provide valuable additional information, however, to ascertain its use for daily clinical practice, future research should determine whether endothelial function can be used to guide treatment in the individual and if this translates into better outcomes.
Article
Repeated sauna treatment, known as Waon therapy, has been shown to improve cardiac function as well as exercise tolerance in patients with chronic heart failure. However, the underlying mechanisms of this therapy regarding these improvements remain to be elucidated. Forty-one patients with chronic heart failure (mean age 68.3 ± 13.5 years old) underwent Waon therapy 5 times a week for 3 weeks. Before and after treatment, a number of assessments were performed in all subjects: 6-minute walk test, echocardiography, determination of neurohumoral factors and number of circulating CD34(+) cells, and a flow-mediated dilation (FMD) test of endothelial function. Cardiopulmonary exercise testing was also performed in 20 patients. Waon therapy increased the left ventricular ejection fraction (from 30.4 ± 12.6% to 32.5% ± 12.8%, p = 0.023) and reduced plasma levels of norepinephrine (from 400 ± 258 to 300 ± 187 pg/ml, p = 0.015) and brain natriuretic peptide (from 550 ± 510 to 416 ± 431 pg/ml, p = 0.035). Waon therapy increased the 6-minute walk distance (from 337 ± 120 to 379 ± 126 m, p <0.001) in association with an improvement in FMD (from 3.5 ± 2.3% to 5.5% ± 2.7%, p <0.001) and an increase in the number of circulating CD34(+) cells (p = 0.025). Changes in 6-minute walk distance were correlated positively with those in the left ventricular ejection fraction and FMD and negatively with those in plasma levels of norepinephrine and brain natriuretic peptide levels. A multivariate analysis revealed that an increase in FMD was the only independent determinant of 6-minute walk distance improvement. Finally, Waon therapy significantly increased peak Vo(2), and this increase was also correlated with changes in FMD. In conclusion, repeated sauna therapy in patients with chronic heart failure improves exercise tolerance in association with improvement in endothelial function.
Article
Sauna therapy has been used for hundreds of years in the Scandinavian region as a standard health activity. Studies document the effectiveness of sauna therapy for persons with hypertension, congestive heart failure, and for post-myocardial infarction care. Some individuals with chronic obstructive pulmonary disease (COPD), chronic fatigue, chronic pain, or addictions also find benefit. Existing evidence supports the use of saunas as a component of depuration (purification or cleansing) protocols for environmentally-induced illness. While far-infrared saunas have been used in many cardiovascular studies, all studies applying sauna for depuration have utilized saunas with radiant heating units. Overall, regular sauna therapy (either radiant heat or far-infrared units) appears to be safe and offers multiple health benefits to regular users. One potential area of concern is sauna use in early pregnancy because of evidence suggesting that hyperthermia might be teratogenic.
Article
A previous report by our team showed that Waon therapy, using a far infrared-ray dry sauna at 60°C, improves cardiac and vascular function in patients with chronic heart failure (CHF). The purpose of the present study was to clarify the effect of Waon therapy on oxidative stress in CHF patients and investigate its mechanism by animal experiments. Forty patients with CHF were divided into control (n=20) and Waon therapy (n=20) groups. All patients received standard optimal medications for CHF. Waon therapy group was treated with Waon therapy daily for 4 weeks. After 4 weeks of Waon therapy, concentrations of hydroperoxide and brain natriuretic peptide (BNP) decreased significantly (hydroperoxide, 422±116 to 327±88U.CARR, P<0.001; BNP, 402±221 to 225±137pg/ml, P<0.001), and the nitric oxide metabolites increased (71.2±35.4 to 92.0±40.5mmol/L, P<0.05). In contrast, none of these variables changed over the 4-week interval in the control group. Furthermore, animal experiments were performed using TO-2 cardiomyopathic hamsters. On immunohistochemistry, cardiac expression of 4-hydroxy-2-nonenal, a marker of oxidative stress, was decreased in the 4-week Waon therapy compared to untreated hamsters. On Western blotting, cardiac expressions of heat shock protein (HSP) 27, manganese superoxide dismutase and HSP32, which reduce oxidative stress, were significantly upregulated in the 4-week Waon therapy compared to untreated hamsters. Waon therapy decreases oxidative stress in patients and hamsters with heart failure.
Article
We have reported previously that Waon therapy improves cardiac and vascular function, and prognosis of patients with chronic heart failure (CHF). CHF is characterized by generalized sympathetic activation and parasympathetic withdrawal. The purpose of this study was to evaluate the effect of Waon therapy on autonomic nervous activity in patients with CHF. Fifty-four patients with CHF, who were receiving conventional therapy for CHF, were divided into Waon therapy and control groups. In the Waon therapy group, 27 patients were treated with medication and Waon therapy. In the control group, 27 patients were treated with only conventional CHF therapy. Cardiac function including cardiac output (CO) and left ventricular ejection fraction (LVEF) was evaluated by echocardiography. The heart rate variability, such as the coefficient of variation of RR intervals (CVRR), the low-frequency (LF) component, high-frequency (HF) component, the LF norm [LF/(LF+HF)], and HF norm [HF/(LF+HF)], were measured at admission and 4 weeks after treatment. Echocardiography demonstrated that CO and LVEF significantly increased after 4 weeks in the Waon therapy group, but did not change in the control group. In the Waon therapy group, CVRR, HF, and HF norm significantly increased 4 weeks after Waon therapy. In addition, the LF/HF ratio and LF norm significantly decreased 4 weeks after Waon therapy. In contrast, these parameters remained unchanged in the control group. Moreover, the HF and HF norm were significantly higher, and the LF/HF ratio and LF norm were significantly lower after 4 weeks of Waon therapy group than after 4 weeks of only conventional therapy. Waon therapy improved cardiac function and autonomic nervous activity by increasing parasympathetic and decreasing sympathetic nervous activity in patients with CHF.
Article
We conducted a prospective multicenter case-control study to confirm the clinical efficacy and safety of Waon therapy on chronic heart failure (CHF). Patients (n=188) with CHF were treated with standard therapy for at least 1 week, and then were randomized to Waon therapy (n=112) or a control group (n=76). All patients continued conventional treatment for an additional 2 weeks. The Waon therapy group was treated daily with a far infrared-ray dry sauna at 60 degrees C for 15 min and then kept on bed rest with a blanket for 30 min for 2 weeks. Chest radiography, echocardiography, and plasma levels of brain natriuretic peptide (BNP) were measured before and 2 weeks after treatment. NYHA functional class significantly decreased after 2 weeks of treatment in both groups. Chest radiography also showed a significant decrease of the cardiothoracic ratio in both groups (Waon therapy: 57.2+/-8.0% to 55.2+/-8.0%, p<0.0001; control: 57.0+/-7.7% to 56.0+/-7.1%, p<0.05). Echocardiography demonstrated that left ventricular diastolic dimension (LVDd), left atrial dimension (LAD), and ejection fraction (EF) significantly improved in the Waon therapy group (LVDd: 60.6+/-7.6 to 59.1+/-8.4 mm, p<0.0001; LAD: 45.4+/-9.3 mm to 44.1+/-9.4 mm, p<0.05; EF: 31.6+/-10.4% to 34.6+/-10.6%, p<0.0001), but not in the control group (LVDd: 58.4+/-10.3 mm to 57.9+/-10.4 mm; LAD: 46.3+/-9.7 mm to 46.2+/-10.1 mm; EF: 36.6+/-14.1% to 37.3+/-14.0%). The plasma concentration of BNP significantly decreased with Waon therapy, but not in the control group (Waon: 542+/-508 pg/ml to 394+/-410 pg/ml, p<0.001; control: 440+/-377 pg/ml to 358+/-382 pg/ml). Waon therapy is safe, improves clinical symptoms and cardiac function, and decreases cardiac size in CHF patients. Waon therapy is an innovative and promising therapy for patients with CHF.
Article
A significant advance in the field of neurotransmission was made with the discovery of presynaptic release-modulating alpha-adrenoreceptors on noradrenergic nerve terminals. The concept of presynaptic modulation of noradrenaline release developed in parallel with the pharmacological evidence for two subtypes of alpha-adrenoreceptors as defined by a different profile of affinity and relative order of potencies for agonists and for antagonists. The alpha 1-adrenoreceptor is stimulated preferentially by methoxamine and cirazoline and blocked selectively by prazosin or corynanthine. The alpha 2-adrenoreceptor is stimulated preferentially by agonists such as clonidine, TL-99, GHT-933, and UK-14,304, and the responses mediated by these agonists are selectively blocked by the alpha 2-adrenoreceptor antagonist idazoxan. In blood vessels, both the alpha 1- and the alpha 2-adrenoreceptor subtypes are present postsynaptically, where they mediate vasoconstriction, although the alpha 1-adrenoreceptor is the predominant receptor in vascular smooth muscle. Presynaptically on noradrenergic nerve terminals, the stimulation of inhibitory alpha 2-adrenoreceptors reduces the depolarization-evoked release of the transmitter. In most vascular beds, the alpha 1-adrenoreceptor is also the preferentially innervated subtype. In spontaneously hypertensive rats, smooth-muscle alpha 2-adrenoreceptors mediate vasoconstrictor responses to exogenous noradrenaline and to sympathetic nerve stimulation to a greater extent than in the corresponding normotensive Wystar-Kyoto rats, which may point to a pathophysiological role of these alpha 2-adrenoreceptors in hypertension.
Article
A warm-water bath (WWB) or sauna bath (SB) has generally been considered inappropriate for patients with severe congestive heart failure (CHF). However, a comprehensive investigation of the hemodynamic effects of thermal vasodilation in CHF has not been previously undertaken. To investigate the acute hemodynamic effects of thermal vasodilation in CHF, we studied 34 patients with chronic CHF (mean age, 58 +/- 14 years). Clinical stages were New York Heart Association functional class II in 2, III in 19, and IV in 13 patients. Mean ejection fraction was 25 +/- 9%. After a Swan-Ganz catheter was inserted via the right jugular vein, the patient had a WWB for 10 minutes at 41 degrees C or an SB for 15 minutes at 60 degrees C. Blood pressure, ECG, echo-Doppler, expiration gas, and intracardiac pressures were recorded before, during, and 30 minutes after each bath. Oxygen consumption increased mildly, pulmonary arterial blood temperature increased by 1.2 degrees C, and heart rate increased by 20 to 25 beats per minute on average at the end of WWB or SB. Systolic blood pressure showed no significant change. Diastolic blood pressure decreased significantly during SB (P < .01). Cardiac and stroke indexes increased and systemic vascular resistances decreased significantly during and after WWB and SB (P < .01). Mean pulmonary artery, mean pulmonary capillary wedge, and mean right atrial pressures increased significantly during WWB (P < .05) but decreased significantly during SB (P < .05). These pressures decreased significantly from the control level after each bath (P < .01). Mitral regurgitation associated with CHF decreased during and 30 minutes after each bath. Cardiac dimensions decreased and left ventricular ejection fraction increased significantly after WWB and SB. In an additional study, plasma norepinephrine increased significantly during SB in healthy control subjects and in patients with CHF and returned to control levels by 30 minutes after SB. Hemodynamics improve after WWB or SB in patients with chronic CHF. This is attributable to the reduction in cardiac preload and afterload. Thus, thermal vasodilation can be applied with little risk if appropriately performed and may provide a new nonpharmacological therapy for CHF.
Article
An adjusted rank correlation test is proposed as a technique for identifying publication bias in a meta-analysis, and its operating characteristics are evaluated via simulations. The test statistic is a direct statistical analogue of the popular "funnel-graph." The number of component studies in the meta-analysis, the nature of the selection mechanism, the range of variances of the effect size estimates, and the true underlying effect size are all observed to be influential in determining the power of the test. The test is fairly powerful for large meta-analyses with 75 component studies, but has only moderate power for meta-analyses with 25 component studies. However, in many of the configurations in which there is low power, there is also relatively little bias in the summary effect size estimate. Nonetheless, the test must be interpreted with caution in small meta-analyses. In particular, bias cannot be ruled out if the test is not significant. The proposed technique has potential utility as an exploratory tool for meta-analysts, as a formal procedure to complement the funnel-graph.
Article
B-type or brain natriuretic peptide (BNP) is a novel natriuretic peptide secreted from the heart that forms a peptide family with A-type or atrial natriuretic peptide (ANP), and its plasma level has been shown to be increased in patients with congestive heart failure. This study was designed to examine the sources and mechanisms of the secretion of BNP in comparison with those of ANP in control subjects and in patients with heart failure. We measured the plasma levels of BNP as well as ANP in 16 patients with dilated cardiomyopathy (11 men and 5 women; mean age, 59 years) and 18 control subjects (9 men and 9 women; mean age, 54 years) by sampling blood from the femoral vein, the aortic root, the anterior interventricular vein (AIV), and the coronary sinus using the newly developed immunoradiometric assay systems. In the control subjects, there was no significant difference in the plasma ANP level between the aortic root and the AIV (24.0 +/- 5.2 pg/mL versus 32.2 +/- 17.0 pg/mL), but there was a highly significant step-up of the level between the AIV and the coronary sinus (32.2 +/- 17.0 pg/mL versus 371.4 +/- 111.1 pg/mL, P < .001). In contrast, there was a significant step-up of the plasma BNP level between the aortic root and the AIV (8.6 +/- 6.4 pg/mL versus 19.0 +/- 11.5 pg/mL, P < .01) but not between the AIV and the coronary sinus (19.0 +/- 11.5 pg/mL versus 28.8 +/- 14.0 pg/mL). On the other hand, in patients with dilated cardiomyopathy, there was a significant step-up in the plasma ANP level between the aortic root and the AIV (280.6 +/- 183.7 pg/mL versus 612.3 +/- 431.6 pg/mL, P < .01) and between the AIV and the coronary sinus (612.3 +/- 431.6 pg/mL versus 1229.0 +/- 772.7 pg/mL, P < .01). There was a significant step-up in the plasma BNP level between the aortic root and the AIV (268.4 +/- 293.2 pg/mL versus 511.6 +/- 458.1 pg/mL, P < .01) but not between the AIV and the coronary sinus (511.6 +/- 458.1 pg/mL versus 529.7 +/- 455.3 pg/mL) in patients with dilated cardiomyopathy. The arteriovenous difference at the AIV of the plasma level of BNP had a significant positive correlation with left ventricular end-systolic volume index (r = 0.859, P < .001) and a significant negative correlation with left ventricular ejection fraction (r = -.735, P < .001). We conclude that (1) BNP is secreted mainly from the left ventricle in normal adult humans as well as in patients with left ventricular dysfunction, whereas ANP is secreted from atria in normal adult humans and also from the left ventricle in patients with left ventricular dysfunction; (2) secretion of BNP as well as ANP from the left ventricle increases in proportion to the severity of the left ventricular dysfunction, suggesting that the secretions of ANP and BNP from the left ventricle are regulated mainly by wall tension of the left ventricle; and (3) the peripheral plasma levels of ANP and BNP reflect the secretion rate of these hormones from the left ventricle and may be used as a marker of the degree of left ventricular dysfunction in patients with left ventricular dysfunction.
Article
Newly discovered circulating peptides, N-terminal pro-brain natriuretic peptide (N-BNP) and adrenomedullin (ADM), were examined for prediction of cardiac function and prognosis and compared with previously reported markers in 121 patients with myocardial infarction. The association between radionuclide left ventricular ejection fraction (LVEF) and N-BNP at 2 to 4 days (r=-.63, P<.0001) and 3 to 5 months (r=-.58, P<.0001) after infarction was comparable to that for C-terminal BNP and far stronger than for ADM (r=-.26, P<.01), N-terminal atrial natriuretic peptide (N-ANP), C-terminal ANP, cGMP, or plasma catecholamine concentrations. For prediction of death over 24 months of follow-up, an early postinfarction N-BNP level > or = 160 pmol/L had sensitivity, specificity, positive predictive value, and negative predictive values of 91%, 72%, 39%, and 97%, respectively, and was superior to any other neurohormone measured and to LVEF. Only 1 of 21 deaths occurred in a patient with an N-BNP level below the group median (Kaplan-Meier survival analysis, P<.00001). For prediction of heart failure (left ventricular failure), plasma N-BNP > or = 145 pmol/L had sensitivity (85%) and negative predictive value (91%) comparable to the other cardiac peptides and was superior to ADM, plasma catecholamines, and LVEF. By multivariate analysis, N-BNP but not ADM provided predictive information for death and left ventricular failure independent of patient age, sex, LVEF, levels of other hormones, and previous history of heart failure, myocardial infarction, hypertension, or diabetes. Plasma N-BNP measured 2 to 4 days after myocardial infarction independently predicted left ventricular function and 2-year survival. Stratification of patients into low- and high-risk groups can be facilitated by plasma N-BNP or BNP measurements, and one of these could reasonably be included in the routine clinical workup of patients after myocardial infarction.
Article
There is currently no objective practical guide to intensity of drug treatment for individuals with heart failure. We hypothesised that pharmacotherapy guided by plasma concentrations of the cardiac peptide aminoterminal brain natriuretic peptide (N-BNP) would produce a superior outcome to empirical trial-based therapy dictated by clinical acumen. 69 patients with impaired systolic function (left-ventricular ejection fraction <40%) and symptomatic heart failure (New York Heart Association class II-IV) were randomised to receive treatment guided by either plasma N-BNP concentration (BNP group) or standardised clinical assessment (clinical group). During follow-up (minimum 6-months, median 9.5 months), there were fewer total cardiovascular events (death, hospital admission, or heart failure decompensation) in the BNP group than in the clinical group (19 vs 54, p=0.02). At 6 months, 27% of patients in the BNP group and 53% in the clinical group had experienced a first cardiovascular event (p=0.034). Changes in left-ventricular function, quality of life, renal function, and adverse events were similar in both groups. N-BNP-guided treatment of heart failure reduced total cardiovascular events, and delayed time to first event compared with intensive clinically guided treatment.
Article
We sought to determine whether sauna therapy, a thermal vasodilation therapy, improves endothelial function in patients with coronary risk factors such as hypercholesterolemia, hypertension, diabetes mellitus and smoking. Exposure to heat is widely used as a traditional therapy in many different cultures. We have recently found that repeated sauna therapy improves endothelial and cardiac function in patients with chronic heart failure. Twenty-five men with at least one coronary risk factor (risk group: 38 +/- 7 years) and 10 healthy men without coronary risk factors (control group: 35 +/- 8 years) were enrolled. Patients in the risk group were treated with a 60 degrees C far infrared-ray dry sauna bath for 15 min and then kept in a bed covered with blankets for 30 min once a day for two weeks. To assess endothelial function, brachial artery diameter was measured at rest, during reactive hyperemia (flow-mediated endothelium-dependent dilation [%FMD]), again at rest and after sublingual nitroglycerin administration (endothelium-independent vasodilation [%NTG]) using high-resolution ultrasound. The %FMD was significantly impaired in the risk group compared with the control group (4.0 +/- 1.7% vs. 8.2 +/- 2.7%, p < 0.0001), while %NTG was similar (18.7 +/- 4.2% vs. 20.4 +/- 5.1%). Two weeks of sauna therapy significantly improved %FMD in the risk group (4.0 +/- 1.7% to 5.8 +/- 1.3%, p < 0.001). In contrast, %NTG did not change after two weeks of sauna therapy (18.7 +/- 4.2% to 18.1 +/- 4.1%). Repeated sauna treatment improves impaired vascular endothelial function in the setting of coronary risk factors, suggesting a therapeutic role for sauna treatment in patients with risk factors for atherosclerosis.
Article
The purpose of this study was to determine the mechanism by which 60 degrees C sauna treatment improves cardiac function in patients with chronic heart failure (CHF). We have previously reported that repeated 60 degrees C sauna treatment improves hemodynamic data and clinical symptoms in patients with CHF. We hypothesized that the sauna restores endothelial function and then improves cardiac function. Twenty patients (62 plus minus 15 years) in New York Heart Association (NYHA) functional class II or III CHF were treated in a dry sauna at 60 degrees C for 15 min and then kept on bed rest with a blanket for 30 min, daily for two weeks. Ten patients with CHF, matched for age, gender and NYHA functional class, were placed on a bed in a temperature-controlled (24 degrees C) room for 45 min as the nontreated group. Using high-resolution ultrasound, we measured the diameter of the brachial artery at rest and during reactive hyperemia (percent flow-mediated dilation, %FMD: endothelium-dependent dilation), as well as after sublingual administration of nitroglycerin (%NTG: endothelium-independent dilation). Cardiac function was evaluated by measuring the concentrations of plasma brain natriuretic peptide (BNP). Clinical symptoms were improved in 17 of 20 patients after two weeks of sauna therapy. The %FMD after two-week sauna treatment significantly increased from the baseline value, whereas the %NTG-induced dilation did not. Concentrations of BNP after the two-week sauna treatment decreased significantly. In addition, there was a significant correlation between the change in %FMD and the percent improvement in BNP concentrations in the sauna-treated group. In contrast, none of the variables changed at the two-week interval in the nontreated group. Repeated sauna treatment improves vascular endothelial function, resulting in an improvement in cardiac function and clinical symptoms.
Article
The extent of heterogeneity in a meta-analysis partly determines the difficulty in drawing overall conclusions. This extent may be measured by estimating a between-study variance, but interpretation is then specific to a particular treatment effect metric. A test for the existence of heterogeneity exists, but depends on the number of studies in the meta-analysis. We develop measures of the impact of heterogeneity on a meta-analysis, from mathematical criteria, that are independent of the number of studies and the treatment effect metric. We derive and propose three suitable statistics: H is the square root of the chi2 heterogeneity statistic divided by its degrees of freedom; R is the ratio of the standard error of the underlying mean from a random effects meta-analysis to the standard error of a fixed effect meta-analytic estimate, and I2 is a transformation of (H) that describes the proportion of total variation in study estimates that is due to heterogeneity. We discuss interpretation, interval estimates and other properties of these measures and examine them in five example data sets showing different amounts of heterogeneity. We conclude that H and I2, which can usually be calculated for published meta-analyses, are particularly useful summaries of the impact of heterogeneity. One or both should be presented in published meta-analyses in preference to the test for heterogeneity.
Article
As blood flows, the vascular wall is constantly subjected to physical forces, which regulate important physiological blood vessel responses, as well as being implicated in the development of arterial wall pathologies. Changes in blood flow, thus generating altered hemodynamic forces are responsible for acute vessel tone regulation, the development of blood vessel structure during embryogenesis and early growth, as well as chronic remodeling and generation of adult blood vessels. The complex interaction of biomechanical forces, and more specifically shear stress, derived by the flow of blood and the vascular endothelium raise many yet to be answered questions:How are mechanical forces transduced by endothelial cells into a biological response, and is there a "shear stress receptor"?Are "mechanical receptors" and the final signaling pathways they evoke similar to other stimulus-response transduction systems?How do vascular endothelial cells differ in their response to physiological or pathological shear stresses?Can shear stress receptors or shear stress responsive genes serve as novel targets for the design of diagnostic and therapeutic modalities for cardiovascular pathologies?The current review attempts to bring together recent findings on the in vivo and in vitro responses of the vascular endothelium to shear stress and to address some of the questions raised above.
Article
The physiologic effect of the sauna in human beings has been studied extensively, but only recently have there been studies to suggest sauna can be an effective therapeutic modality for patients with cardiovascular disease, especially for those with congestive heart failure. The data reported to date have been promising, but definitive studies are not possible because sauna treatment would be difficult to evaluate in a double-blind, placebo-controlled study.