S Stamatelopoulos

Harokopion University of Athens, Athínai, Attica, Greece

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Publications (118)571.33 Total impact

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    ABSTRACT: The early appearance of ventricular fibrillation (VF) following acute myocardial infarction (MI) is associated with adrenergic effects and electrical interactions although some early "mechanical" changes may also occur. The aim of the present experimental study was to examine whether early changes in the functional geometry of left ventricular (LV) contraction may be associated with ventricular arrhythmias occurring during the first 120min of MI. In 11 swine left anterior descending (LAD) coronary artery ligation was performed. Aortic flow, LV end-diastolic pressure (LVEDP), LV long and short axis lengths were measured and their fractional shortening (FS) was calculated before and during the initial 120min period of MI. LV long axis FS and aortic flow decreased (p<0.001) whereas LVEDP increased (p<0.01) in all 11 animals within 30min following LAD ligation. LV long and short axis lengths and LV short axis FS did not change significantly. VF occurred in 5 of the 11 animals within this 30min period. LV short axis FS decreased (p<0.05) in all 5 animals prior to VF and increased (p<0.05) in all 6 animals without VF. In 3 of the 6 animals that had no VF during the initial 30min VF occurred later. Similarly, LV short axis FS decreased prior to VF in all those 3 animals. LV short axis FS did not decrease in any of the remaining 3 swine without VF during the same period of time. Early changes in the functional geometry of LV contraction, in the form of a reduction of LV short axis FS, are associated with a greater incidence of VF in experimental acute MI.
    Resuscitation 11/2010; 82(2):207-12. DOI:10.1016/j.resuscitation.2010.10.006 · 3.96 Impact Factor
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    ABSTRACT: In the present study we measured carotid and femoral intima-media thickness (IMT) by B-Mode ultrasonography, as well as angiographic extent and severity of coronary artery disease in patients referred for coronary arteriography, to assess the relation between individual IMT, scores incorporating IMT from the carotid and femoral arteries and the extent and severity of coronary artery disease. Two hundred and two patients referred for elective coronary angiography underwent ultrasound imaging of both carotid and femoral arteries for IMT measurements. An IMT score was developed as the number of sites with abnormal IMT (range 0-8). Multiple regression analysis indicated that IMT score was independently related to Gensini score, age and glucose levels. A high risk IMT score predicted an extended coronary artery disease although a low or medium risk IMT score cannot exclude the possibility of multivessel disease. Also, a high risk group could predict the performance of revascularization procedures and all cardiovascular events during a follow-up of 14.5 +/- 2.4 months. IMT incorporating data from common and internal carotid artery, carotid bifurcation and femoral artery are well correlated with the extent of coronary atherosclerosis, much better than individual IMT. Patients with high IMT score usually have multivessel coronary artery disease and are at increased risk for subsequent cardiovascular events.
    The International Journal of Cardiovascular Imaging 11/2005; 21(5):495-501. DOI:10.1007/s10554-004-8165-x · 2.32 Impact Factor
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    ABSTRACT: The association between hypothyroidism and increased vascular resistance, arterial wall thickening and endothelial dysfunction is well recognized. The aim of the present study was to examine if hypothyroid subjects have increased arterial stiffness, a risk factor for cardiovascular morbidity and mortality. Sixty-five subjects (59 females and 6 males) with normal thyroid function or hypothyroidism of varying degree were investigated by radial artery applanation tonometry and pulse wave analysis, for evaluation of arterial stiffness. Serum TSH values were positively correlated with central systolic blood pressure (r=0.258, p=0.037), central pulse pressure (r=0.316, p=0.010), augmentation pressure (r=0.299, p=0.015) and negatively with reflection time index (RTI), which indicates the pressure wave velocity (r=-0.311, p=0.012). Hypothyroid patients presented higher central systolic pressure and pulse pressure, higher augmentation pressure and lower RTI, indicating increased arterial stiffness in these subjects. RTI was independently related to age, central systolic pressure and TSH. Mild changes of arterial stiffness were observed even in subjects with TSH range 2.01-4.0 muU/ml suggesting that this group may have an early stage of mild thyroid failure. Hypothyroidism, even in the subclinical stage, is associated with changes in arterial stiffness. The observed abnormalities in arterial stiffness may have detrimental effects on left ventricular function and coronary perfusion in hypothyroid subjects.
    International Journal of Cardiology 09/2005; 103(1):1-6. DOI:10.1016/j.ijcard.2004.05.068 · 6.18 Impact Factor
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    ABSTRACT: The association between hypothyroidism and increased vascular resistance, arterial wall thickening and endothelial dysfunction is well recognized. The aim of the present study was to examine if hypothyroid subjects have increased arterial stiffness, a risk factor for cardiovascular morbidity and mortality. Sixty-five subjects (59 females and 6 males) with normal thyroid function or hypothyroidism of varying degree were investigated by radial artery applanation tonometry and pulse wave analysis, for evaluation of arterial stiffness. Serum TSH values were positively correlated with central systolic blood pressure (r=0.258, p=0.037), central pulse pressure (r=0.316, p=0.010), augmentation pressure (r=0.299, p=0.015) and negatively with reflection time index (RTI), which indicates the pressure wave velocity (r=-0.311, p=0.012). Hypothyroid patients presented higher central systolic pressure and pulse pressure, higher augmentation pressure and lower RTI, indicating increased arterial stiffness in these subjects. RTI was independently related to age, central systolic pressure and TSH. Mild changes of arterial stiffness were observed even in subjects with TSH range 2.01-4.0 muU/ml suggesting that this group may have an early stage of mild thyroid failure. Hypothyroidism, even in the subclinical stage, is associated with changes in arterial stiffness. The observed abnormalities in arterial stiffness may have detrimental effects on left ventricular function and coronary perfusion in hypothyroid subjects.
    International Journal of Cardiology 09/2005; 103(1):1-6. DOI:10.1016/j.ijcard.2004.05.068 · 6.18 Impact Factor
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    ABSTRACT: Folic acid therapy has been shown to improve endothelial function in patients with familial hypercholesterolaemia via a possible antioxidant mechanism. Data on the possible role of folic acid in hypercholesterolaemic patients receiving statins are lacking. In the present study we tested the hypothesis that folic acid supplementation improves endothelial function in patients with hypercholesterolaemia and treatment with statins. Thirty-four hypercholesterolaemic patients receiving statins participated in the study; all subjects underwent measurement of endothelium-dependent, flow-mediated dilatation of the brachial artery and subsequently randomized to receive 5 mg of the folic acid (n=17) or placebo (n=17) for 4 weeks. Flow-mediated dilatation of the brachial artery was repeated at the end of the 4-week period. Folic acid and placebo groups were comparable regarding age, sex, smoking, hypertension, coronary artery disease, obesity, family history and blood lipids. Folic acid administration resulted in an improvement of flow-mediated dilatation (4.7+/-3.2% to 7.1+/-3.1%, P=0.02), whereas there was no improvement after placebo administration (5.7+/-3.8% to 5.6+/-2.2%, ns). No significant change in nitrate-induced, endothelium- independent dilatation was observed after folic acid or placebo (ns). Oral administration of folic acid (5 mg) for 4 weeks improves endothelial function in patients with hypercholesterolaemia treated with statins, with possible beneficial effects on the prognosis of these patients.
    European Journal of Cardiovascular Prevention and Rehabilitation 11/2004; 11(5):416-20. DOI:10.1097/01.hjr.0000206331.10791.ad · 3.69 Impact Factor
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    ABSTRACT: Despite the well-known beneficial effects of the intra-aortic balloon pump (IABP) generally, there are still some clinical conditions accompanied by IABP ineffectiveness. The aim of this study was the investigation of the independent effects of arterial stiffness and blood pressure on acute IABP effectiveness. For this purpose, a mock circulatory system and 20 patients with cardiogenic shock due to acute myocardial infarction, were employed. It was shown that IABP acute efficiency was determined primarily by arterial compliance (AC) rather than blood pressure alone. IABP induced low hemodynamic effects in patients with systolic blood pressure > 80 mm Hg but with increased AC, whereas IABP resulted in greater hemodynamic effectiveness in cases with systolic pressure < 70 mm Hg but lower AC. The present study provides evidence concerning the hemodynamic conditions, which might lead to optimization of IABP or to the prediction of its acute hemodynamic performance, based on both measurements of AC and blood pressure.
    Artificial Organs 09/2004; 28(8):717-27. DOI:10.1111/j.1525-1594.2004.00080.x · 1.87 Impact Factor
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    ABSTRACT: Tamoxifen is a selective estrogen-receptor modulator shown to improve several cardiovascular risk factors in postmenopausal women with breast cancer. In animal studies tamoxifen inhibits the progression of atherosclerosis. Although the presence of a history with tamoxifen treatment is related to a lower intima-media thickness (IMT) of the common carotid artery, data from controlled follow-up studies are lacking to support this observation. We examined 14 postmenopausal women with early stage breast cancer with indication for tamoxifen treatment (20 mg/d) and 13 healthy postmenopausal women. Flow-mediated dilatation (FMD) of the brachial artery, combined carotid IMT, and aortic pulse wave were measured before and 6 months after treatment in the tamoxifen group and at the same times in the control group. FMD and IMT were significantly increased and decreased, respectively, in the treatment group compared to the control group (FMD: +2.2% +/- 0.9% vs +0.085% +/- 1%, P =.012; IMT: -0.088 +/- 0.03 mm vs +0.04 +/- 0.03 mm, P =.018, mean +/- standard error of the mean, treatment vs control group). These differences remained significant even when adjusted for age, duration of menopause, and cardiovascular risk factors. Low-density lipoprotein cholesterol was also significantly reduced after tamoxifen treatment. Tamoxifen treatment slows the progression of atherosclerosis in postmenopausal women with breast cancer as assessed by changes in carotid IMT. An improvement in endothelial function and blood lipid profile may be the reason for this beneficial effect.
    American heart journal 07/2004; 147(6):1093-9. DOI:10.1016/j.ahj.2003.12.029 · 4.56 Impact Factor
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    ABSTRACT: Early diagnosis of heart transplant rejection is mandatory, since even mild rejection can rapidly progress to more severe rejection. Noninvasive diagnosis of heart transplant rejection still remains a challenge. The purpose of the study was to determine a possible association between myocardial performance index (MPI) and biopsy score of the heart transplant. This is a retrospective cohort analysis of 99 complete Doppler echocardiographic studies from 24 consecutive patients (23 men) performed within 24 h of endomyocardial biopsy. Mean age of the cohort was 50 +/- 9 years and mean time from transplantation was 19 +/- 21 months (1-81). All patients were in sinus rhythm. Myocardial performance index was calculated as the ratio of isovolumic contraction time plus isovolumic relaxation time divided by ejection time. Left ventricular dimensions, left ventricular mass, ejection fraction, and a number of Doppler indices (E-point velocity, A-point velocity, deceleration time, and deceleration slope) were also measured. The International Society for Heart and Lung Transplantation (ISHLT) grading system was used for the classification of endomyocardial biopsies. Myocardial performance index was significantly prolonged (0.60 +/- 0.13, 0.68 +/- 0.08, 0.75 +/- 0.20, in biopsy scores 0, IA, and IB, respectively; p<0.001). Isovolumic contraction time was significantly prolonged; isovolumic relaxation time was not significantly changed. Ejection time and deceleration time were significantly shortened. Multivariate stepwise regression analysis revealed that MPI and deceleration time were the only independent predictors of biopsy score (r=0.48, F=10.53, p<0.0001). Myocardial performance index seems to be a useful adjunct in the follow-up of cardiac transplant patients. These preliminary data suggest that a larger study may be indicated to clarify the relevance of myocardial performance index.
    Clinical Cardiology 06/2004; 27(6):352-8. DOI:10.1002/clc.4960270611 · 2.23 Impact Factor
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    ABSTRACT: This study was designed to research the effect of hypercholesterolaemia and ascorbic acid on forearm blood flow (FBF) reactive hyperaemia (RH). Reactive hyperaemia seems to be at least partly endothelium-dependent. Endothelial dysfunction has been described in patients with hypercholesterolaemia, and has been reversed with ascorbic acid administration. Forearm blood flow was studied with venous occlusion plethsmography in 26 healthy volunteers and 46 hypercholesterolaemic patients. Hypercholesterolaemic patients were divided into two groups. Group A comprised 25 patients, who received ascorbic acid and group B comprised 21 patients, who received placebo. All subjects underwent measurement of FBF at baseline and during RH (phase A). Forearm blood flow during RH was measured every 15 seconds for three minutes. Subsequently patients in group A received 2 g of ascorbic acid orally in the form of effervescent tablets, and patients in group B received placebo orally in the same form. Forearm blood flow measurements at baseline and during RH were repeated two hours later (phase B). Maximal percent increase of FBF was significantly higher in healthy subjects than in hypercholesterolaemic patients (139.1+/-12.1% versus 73.1+/-11.0% respectively, P<0.05). Duration of RH was smaller in hypercholesterolaemic patients compared to normal subjects (60.9+/-17.1 seconds versus 105.6+/-10.2 seconds, P<0.05). Administration of ascorbic acid but not of placebo increased the duration of RH (69.1+/-11.1 seconds versus 104.1+/-12.2 seconds, P<0.05) but not of peak RH FBF. Hypercholesterolaemia seems to impair both the early and late phase of RH. Ascorbic acid improves only the duration of RH, possibly due to its antioxidant effect on endothelium.
    European Journal of Cardiovascular Prevention and Rehabilitation 04/2004; 11(2):149-54. DOI:10.1097/01.hjr.0000095049.46631.b9 · 3.69 Impact Factor
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    ABSTRACT: Impaired left ventricular diastolic function is a common finding in essential hypertension. In order to investigate possible relationships between flow velocity through the mitral valve (E/A; index of left ventricular diastolic function) and 24-hour blood pressure and heart rate variations, 198 patients with mild to moderate essential hypertension were studied by Doppler echocardiography and ambulatory blood pressure monitoring. They were divided according to age into group 1 (n = 88, age 40-54 years) and group 2 (n = 110, age 55-79 years). Each group was divided into subgroups with (1a, 2a) or without (1b, 2b) left ventricular hypertrophy according to the end-diastolic posterior wall thickness and/or the interventricular septum thickness. In a multivariate stepwise regression analysis, age (beta = -0.25, p < 0.0001), posterior wall thickness (beta = -0.31, p < 0.0057) and mean heart rate during the day (beta = -0.34, p < 0.0284) were the independent predictors of E/A in the pooled population. In group 1a (young subjects with left ventricular hypertrophy), mean systolic blood pressure during the night (beta = -0.33, p < 0.041) was the only independent predictor of E/A. In the elderly group without left ventricular hypertrophy (group 2b), the mean heart rate during the day (beta = -0.44, p < 0.0000) and mean pulse pressure during the night (beta = -0.60, p < 0.0007) were the independent predictors of E/A. The new finding provided by this study is that in elderly hypertensive patients without left ventricular hypertrophy, a large pulse pressure at night may serve as an independent predictor of abnormal left ventricular diastolic filling.
    Cardiology 02/2004; 102(2):108-14. DOI:10.1159/000078149 · 2.04 Impact Factor
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    ABSTRACT: Short-term cigarette smoking is associated with persistent endothelial dysfunction. Data on the reversibility of this effect with per os antioxidants after short-term smoking are lacking. This study examines the effect of orally administered ascorbic acid on cigarette smoking-induced endothelial dysfunction. In the present double-blind, randomized, crossover study, 19 healthy subjects (28.7 +/- 6.8 years, mean +/- SD) were examined by high-resolution ultrasonography of the brachial artery before and 0, 30, 60, 90, and 120 minutes after smoking a cigarette. Flow-mediated dilatation (FMD) was used as a method to examine endothelial function. Measurements were performed on two different days, 2 hours after oral administration of 2 g of ascorbic acid or placebo. FMD was similar for each subject between the two visits at baseline. FMD was significantly decreased after smoking with both placebo and ascorbic acid. However, there was a significant beneficial effect of ascorbic acid on the FMD change over time after smoking. After smoking, the FMD dropped to less than half of the baseline value. Thereafter in the placebo group, FMD increased to 70% of baseline value in 90 minutes, but in the ascorbic acid group the FMD increased to 70% of baseline value in 46 minutes. Oral administration of ascorbic acid attenuates endothelial dysfunction after short-term cigarette smoking by shortening its duration.
    International Journal for Vitamin and Nutrition Research 12/2003; 73(6):417-22. DOI:10.1024/0300-9831.73.6.417 · 1.00 Impact Factor
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    ABSTRACT: Three patients, 2 women and 1 man, with primary (AL) amyloidosis without congestive heart failure are described; all 3 patients presented reduced I-123 metaiodobenzylguanidine (MIBG) myocardial uptake suggesting marked cardiac sympathetic denervation. This is the first time myocardial adrenergic denervation is described in patients with AL amyloidosis without evidence of congestive heart failure; the observed denervation could be implicated in the pathogenesis of cardiac conduction disturbances which are common in this disease.
    Amyloid 07/2003; 10(2):117-20. DOI:10.3109/13506120309041733 · 2.51 Impact Factor
  • Journal of the American College of Cardiology 03/2003; 41(6):425-426. DOI:10.1016/S0735-1097(03)81267-6 · 15.34 Impact Factor
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    ABSTRACT: Previous studies have shown that patients with Raynaud's phenomenon secondary to systemic sclerosis present abnormal endothelial function; the mechanisms responsible for the endothelial dysfunction are unknown but increased vascular oxidative stress could be a possible cause. The hypothesis that a potent water-soluble antioxidant can reverse endothelial dysfunction in these patients was tested in the present study. We examined 11 female patients with Raynaud's phenomenon secondary to systemic sclerosis and ten healthy control women by ultrasound imaging of the brachial artery to assess flow-mediated (endothelium-dependent) and nitrate-induced (endothelium-independent) vasodilatation. Flow-mediated dilatation and nitrate-induced dilatation were significantly reduced in patients with Raynaud's phenomenon, indicating abnormal endothelial and smooth muscle cell function. Patients with Raynaud's phenomenon entered a double-blind, randomized, crossover placebo-controlled trial and received orally 2 g of ascorbic acid or placebo; vascular studies were repeated two hours after ascorbic acid or placebo administration. Flow-mediated dilatation did not improve after ascorbic acid (1.6 +/- 2.2% to 2.2 +/- 2.5%, ns) or placebo administration (1.2 +/- 1.9% to 1.7 +/- 1.4%, ns); also nitrate-induced dilatation was similar after ascorbic acid or placebo (16 +/- 7.4% vs 17 +/- 8%, ns), suggesting no effect of ascorbic acid on endothelial and vascular smooth muscle function. In conclusion, ascorbic acid does not reverse endothelial vasomotor dysfunction in the brachial circulation of patients with Raynaud's phenomenon secondary to systemic sclerosis. The use of different antioxidants or different dosing of ascorbic acid may be required to show a beneficial effect on endothelial vasodilator function.
    International Journal for Vitamin and Nutrition Research 03/2003; 73(1):3-7. DOI:10.1024/0300-9831.73.1.3 · 1.00 Impact Factor
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    ABSTRACT: Mitral valve prolapse (MVP) has been reported to be associated with systemic lupus erythematosus (SLE). The aim of the present study was to determine the prevalence of MVP in SLE patients, assess its clinical significance and examine the possible association of this entity with other autoimmune indices. Eighty-seven consecutive SLE patients attending the rheumatology clinic and 73 normal control subjects were examined by M-mode, two-dimensional color-Doppler echocardiography. Serum samples were examined for various organ and non-organ specific autoantibodies. MVP was detected in 19/87 patients with SLE and in four of the healthy controls(P = 0.0057). SLE patients with MVP were younger (33.6 +/- 12.4 years) than those without MVP (41. +/- 12.9, P = 0.04) and with shorter duration of the disease (P = 0.03). We found a statistically higher prevalence of anticardiolipin antibodies (aCL) in SLE patients with prolapse (11/19) compared with SLE patients without prolapse (15/68, P = 0.04). This association was independent of age. The aCL-lgG levels were significantly higher in SLE patients with MVP (32.37 +/- 43.26) compared with SLE patients without MVP (22.24 +/- 29.95, P = 0.04). Thyroid autoantibodies tended to be more common in S LE patients with MVP. Th e prevalence of MVP is increased in SLE patients. The presence of aCL and of organ-specific autoantibodies in SLE patients with MVP might indicate the autoimmune origin of MVP. The possibility that SLE patients with MVP may be predisposed to further autoimmune diseases should be considered.
    Lupus 02/2003; 12(4):308-11. DOI:10.1191/0961203303lu314oa · 2.48 Impact Factor
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    ABSTRACT: L-Arginine is a nitric oxide precursor, which augments endothelium-dependent vasodilatation in hypercholesterolemic humans and animals. Endothelium-dependent vasodilation is attenuated in patients with hypertension; however the effects of oral L-arginine on endothelial function of the conduit arteries in patients with essential hypertension have not previously been investigated. In a prospective randomized double blind trial, 35 patients with essential hypertension received either 6 g L-arginine (18 subjects) or placebo (17 subjects). Patients were examined for flow-mediated endothelium-dependent dilatation of the brachial artery before and 1.5 h after administration of L-arginine or placebo. At the end of the protocol the nitrate-induced, endothelium-independent vasodilatation was evaluated. Two groups of L-arginine and placebo were similar regarding age, sex, blood lipids, smoking, diabetes, coronary artery disease, body mass index, intima-media thickness of the common carotid artery, clinics blood pressure and baseline brachial artery parameters. Administration of L-arginine or placebo did not change significantly heart rate, blood pressure, baseline diameter, blood flow or reactive hyperemia. L-Arginine resulted in a significant improvement of flow-mediated dilatation (1.7+/-3.4 vs. 5.9+/-5.4%, P=0.008) while placebo did not significantly change this parameter (3.0+/-2.7 vs. 3.1+/-2.2%, P=ns). The effect of L-arginine on flow-mediated dilatation was significantly different from the effect of placebo (P=0.05). L-Arginine did not significantly influence nitrate-induced dilatation (16+/-6.9 vs. 17.7+/-6.7%, P=ns). Oral administration of L-arginine acutely improves endothelium-dependent, flow-mediated dilatation of the brachial artery in patients with essential hypertension. The long-term effects of L-arginine in these patients require further investigation.
    International Journal of Cardiology 01/2003; 86(2-3):317-23. DOI:10.1016/S0167-5273(02)00413-8 · 6.18 Impact Factor
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    ABSTRACT: A case of post-transplantation pneumonia due to Candida krusei is reported. A 42-year-old man was admitted 28 days after heart transplantation with cough, pleuritic pain and fever. A chest computed tomograph showed multiple alveolar infiltrates bilaterally. He received broad-spectrum antibiotics, fluconazole for oral candidiasis, and cotrimoxazole for possible Pneumocystis carinii. A short-lived period of improvement was followed by respiratory failure. Cultures of bronchial washings grew C. krusei and C. albicans. The infection was documented by histology and culture obtained by transthoracic aspiration. Treatment with amphotericin B was initiated, but the patient died. Histology and culture of a pulmonary specimen, obtained immediately post mortem, further documented the infection with C. krusei.
    Clinical Microbiology and Infection 01/2003; 8(12):806-9. DOI:10.1046/j.1469-0691.2002.00488.x · 5.20 Impact Factor
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    ABSTRACT: Heart rate (HR) has been characterized as an important cardiovascular parameter that affects acute hemodynamic performance of intra-aortic balloon counterpulsation (IABC). However, the effect of HR on hemodynamics during mechanical assistance by the IABC has neither been clarified nor quantified. We sought to evaluate the relationship between IABC and HR and also to examine whether there is a range of HR with optimum hemodynamic response to IABC. METHODS: 20 patients (14 males--6 females, mean age 64.4 +/- 11.4 years) with post-infarction cardiogenic shock undergoing IABC treatment were evaluated. Hemodynamics were recorded for each patient once per day during the assistance period; 131 measurements were taken and thus a wide range of heart rates was obtained (64-141 bpm). The following changes in aortic pressures were used to evaluate acute IABC performance on: a) the maximal increase of diastolic aortic pressure induced by IABC and b) the reduction in systolic and end-diastolic aortic pressure. RESULTS: Non-linear regression analysis and analysis of variance revealed that a significant correlation exists between IABC performance indices and heart rate. At HR<80 bpm, IABC performance tended to be reduced, whereas the increase in HR above 110 bpm resulted in a significant reduction of all IABC performance indices. In contrast, IABC operating at 80-110 bpm resulted in optimum hemodynamic performance. In conclusion, the effect of heart rate on IABC performance is non-linear indicating that IABC may be more effective when operating within 80-110 bpm.
    The International journal of artificial organs 12/2002; 25(12):1160-5. · 1.45 Impact Factor
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    ABSTRACT: The difference between clinic and daytime ambulatory blood pressure is referred to as the white-coat effect. In this study, we investigated (i) the magnitude of the white-coat effect in subjects with different daytime ambulatory blood pressure levels, and (ii) the association of the white-coat effect with left ventricular mass. A total of 1581 subjects underwent clinic blood pressure readings, 24-h ambulatory blood pressure monitoring and left ventricular echocardiographic assessment. Their mean daytime systolic blood pressure varied from 88.0 to 208.9 mmHg and their mean daytime diastolic blood pressure from 40.3 to 133.0 mmHg. A negative correlation was found between the systolic or diastolic white-coat effect and the systolic or diastolic daytime ambulatory blood pressure (r = -0.22, P < 0.000 and r = -0.50, P < 0.000, respectively). Left ventricular mass significantly correlated with ambulatory blood pressure (P < 0.001), but there was no association between left ventricular mass and clinic blood pressure or white-coat effect. Furthermore, the white-coat effect was reversed at the highest level of systolic or diastolic daytime ambulatory blood pressure (systolic over 170 mmHg or diastolic over 100 mmHg) when systolic or diastolic daytime ambulatory blood pressure was higher than systolic or diastolic clinic blood pressure (ambulatory blood pressure hypertension). The white-coat effect shows an inverse association with daytime ambulatory blood pressure level (systolic or diastolic), being significantly more prominent for levels below 140/80 mmHg for systolic/diastolic daytime ambulatory blood pressure and reversed with daytime ambulatory blood pressure levels above 170/100 mmHg.
    Blood Pressure Monitoring 10/2002; 7(5):271-6. DOI:10.1097/00126097-200210000-00004 · 1.18 Impact Factor
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    ABSTRACT: Quantitative data concerning the effect of arterial compliance (AC) on the effectiveness of intra-aortic balloon counterpulsation (IABC) are lacking. The main objective of this study was to investigate the relationship between AC and IABC performance. For this purpose we constructed a Windkessel, lumped-element, hydraulic model of the systemic circulation. The model consisted of a left ventricular assist device (LVAD), a compliance chamber, a peripheral resistor and two open reservoirs. Two Datascope Driving systems were used to operate the LVAD and intra-aortic balloon. We studied the effect of arterial compliance on the effectiveness of IABC at different levels of mean pressure (55, 75 and 95 mmHg) and heart rates (80, 100, 120 bpm). Three indices were used to evaluate IABC performance: the reduction of systolic and end-diastolic "arterial" pressure and the augmentation of diastolic pressure, induced by the IABC. A 22% decrease in AC (1.8-1.4 ml/mmHg) lead to a 30-40% increase in the indices of IABC performance, independently from pressure. In conclusion, arterial compliance significantly affects IABC efficacy and it could be considered as a further clinical criterion to decide IABC application.
    Medical Engineering & Physics 06/2002; 24(4):279-84. DOI:10.1016/S1350-4533(02)00013-9 · 1.84 Impact Factor

Publication Stats

2k Citations
571.33 Total Impact Points

Institutions

  • 1999–2010
    • Harokopion University of Athens
      Athínai, Attica, Greece
  • 1999–2005
    • National Technical University of Athens
      • School of Mechanical Engineering
      Athínai, Attica, Greece
  • 2004
    • National and Kapodistrian University of Athens
      • Division of Clinical Therapeutics
      Athínai, Attica, Greece
  • 1996–2004
    • Alexandra Regional General Hospital
      Athínai, Attica, Greece
  • 1997–2003
    • Κωνσταντοπούλειο νοσοκομείο Νέας Ιωνίας (Η Αγία Όλγα)
      Athínai, Attica, Greece
  • 2000
    • Utrecht University
      Utrecht, Utrecht, Netherlands
    • University of Utah
      Salt Lake City, Utah, United States
    • BMI The Alexandra Hospital
      Cheadle Hulme, England, United Kingdom
  • 1998
    • University of Ioannina
      • Division of Psychiatry
      Yannina, Epirus, Greece