[show abstract][hide abstract] ABSTRACT: Background. Ivabradine is an If ion current inhibitor that has proved to reduce mortality in patients with systolic heart failure by slowing heart rate without decreasing myocardial contractility. Photoplethysmography is a simple, low-cost optical technique that can evaluate vascular function and detect changes in blood flow, pulse, and swelling of tissular microvascular space. Objective. To evaluate the effect of ivabradine on endothelial function by photoplethysmography in diastolic and right heart failure patients. Methodology. 15 patients were included (mean age of 78.1 ± 9.2 years) with optimally treated diastolic and right heart failure. They underwent photoplethysmography before and after induced ischemia to evaluate the wave blood flow on the finger, using the maximum amplitude time/total time (MAT/TT) index. Two measurements were made before and after oral Ivabradine (mean 12.5 mg a day during 6 months of followup). Results. In the study group, the MAT/TT index was 29.1 ± 2.2 versus 24.3 ± 3.2 (P = 0.05) in basal recording and 30.4 ± 2.1 versus 23.3 ± 2.9 (P = 0.002), before versus after ischemia and before versus after Ivabradine intervention, respectively. Conclusions. Ivabradine administration improves endothelial function (shear stress) in diastolic and right heart failure patients.
Cardiology research and practice. 01/2013; 2013:603913.
[show abstract][hide abstract] ABSTRACT: The aim of this study is to determine the prevalence and prognostic value of elevated cardiac troponin (cTnT) and its association with clinical characteristics according to renal function status in patients with stable heart failure.
In a prospective observational study, 152 consecutive patients from the Heart Failure Clinic of the INCMNSZ were followed for a period of 42 months. All underwent clinical evaluation, echocardiography, and determination of body composition by electric bioimpedance to identify hypervolemia. Concentrations of cTnT were quantified by immunoassay with electrochemoluminescence and > or = 0.02 ng/mL levels were considered elevated. Also glomerular filtration rate (eGFR) was estimated using the Cockcroft-Gault equation.
Elevated cTnT was significantly associated with increased all-cause mortality in the observational period even after adjusting for eGFR < 60 mL/min/1.73 m2 and clinical findings such as hypertension, functional class, loop diuretics, angiotensin converting enzyme inhibitors, pulmonary pressure and hypervolemia in Cox regression analysis with a hazard ratio of 4.58 (95% confidence interval: 1.84-11.45).
Heart failure patients with elevated cardiac-specific troponin T are at increased risk of death independently of the presence of chronic kidney disease.
[show abstract][hide abstract] ABSTRACT: Heart failure (HF) patients can benefit from a proper RS. We had observed that they show an increase in the number of arrhythmias during the first year of pharmacological treatment.
We carried out a prospective observational study in which patients in an HF Clinic were included when they had follow-up Holter monitoring. Patients also had a baseline myocardial perfusion scan (Tc99 sestaMIBI/dypiridamole) and a control scan.
We included 90 patients with follow-up Holter and 35 with scintigraphy, for analysis. Fifty-six (62.2%) were men and the average age was 60.8 +/- 14.6 years. Follow-up periods were divided by six-month intervals up to 18 months or more, an increase in premature ventricular contractions (PVCs) occurred in the six-month to one-year period (1915.4 +/- +/- 4686.9 vs. 2959 +/- 6248.1, p = 0.09). In the one-year to 18-month control, PVCs went from 781.6 +/- 1082.4 to 146.9 +/- 184.1, p = 0.05. The increase in PVCs correlated with a reduction in scintigraphy-detected ischemic territories, 5.64 +/- 5.9 vs. 3.18 +/- 3 (p = 0.1) and a gain in those showing a reverse redistribution pattern (0.18 +/- 0.6 vs. 2.09 +/- 4.01, p = 0.1). Necrotic territories and time domain heart rate variability did not show significant changes.
PVCs increase during the first year of HF treatment, and then they tend to diminish and stabilize. These changes seem to correlate with changes in the perfusion state of the patient. While ischemic territories decrease, reverse redistribution increases, showing that endothelial dysfunction could have a relevant role in arrhythmia generation, possibly because of membrane instability of recovered hibernating myocardium.
[show abstract][hide abstract] ABSTRACT: Microalbuminuria is considered a major risk factor predisposing to cardiovascular morbidity and mortality. Microalbuminuria levels in patients with or without diabetes have been associated with a higher risk of chronic heart failure (HF). However, there are limited data regarding prevalence of microalbuminuria in chronic heart failure and its prognostic value. The aim of this study was to assess the occurrence of microalbuminuria in chronic heart failure patients as well as its association with clinical, echocardiographic, and body composition markers.
In a cross-sectional study, we included 72 chronic heart failure patients (NYHA I-III) on standard HF therapy. All patients had an echocardiogram and body composition by vector bioelectric impedance analysis (measured by Body Stat Quad Scan).
The studied population consisted of 64% men at mean age of 62.6 +/- 15.1 years. Patients were divided into systolic and diastolic HF groups. Microalbuminuria was observed in 40% of diastolic and 24% systolic HF patients (p = 0.04). Microalbuminuria was present in more patients with volume overload (80 vs. 21.9%, p = 0.002), with a worse phase angle and lower serum albumin (4.7 vs. 5.9 degrees and 3.5 vs. 4.0 mg/dl, p = 0.02) and higher pulmonary arterial pressure compared with patients without microalbuminuria in systolic HF patients. There was no significant association between frequency of microalbuminuria and ejection fraction. In the diastolic HF group, the presence of microalbuminuria was not associated with any known risk factor.
Microalbuminuria was more frequent in diastolic than systolic HF patients. In systolic HF patients microalbuminuria was associated with factors known to be markers of worse prognosis.
[show abstract][hide abstract] ABSTRACT: Serum levels of aldosterone in heart failure are increased up to 20 times compared to normal subjects. After an acute myocardial infarction, aldosterone increases progressively as well as interstitial fibrosis and collagen synthesis from cardiac fibroblasts, forming a patchy heterogeneous interstitial collagen matrix that affects ventricular function. Even if angiotensin converting enzyme inhibitors (ACEI) or angiotensin II receptor antagonists (ARA) can reduce aldosterone levels early during treatment, they increase again after a 12 week treatment. The aim of this study was to evaluate the changes in structure and function of the left ventricle in symptomatic (NYHA I-III) diastolic heart failure patients receiving an aldosterone receptor antagonist.
Twenty-eight subjects with diastolic heart failure, on BB, ACEI and/ or ARA were randomized to receive spironolactone (group A) on a mean dose of 37.5 mg once a day (n = 14, age 63.7 +/- 21.6 years and body mass index, BMI 27.5 +/- 9.4), or not (group B, n = 14, Age 64.8 +/- 11.9, BMI 26.9 +/- 4.7). All patients were followed-up for a mean of 13.79 +/- 0.99 months.
Group A showed a 42.8% ischemic origin of heart failure, while in group B was 55% (p = 0.2). No other co-morbidities were significativelly different among both groups. Mean percentage of changes by echocardiogram was as follows: Interventricular septum (IVS) -12.2 +/- 11% vs. 1.3 +/- 15.2 (p = 0.03), pulmonary systolic artery pressure (PSAP was 0.99 +/- 3.8% vs. 10.5 +/- 9.1, p = 0.05). Other parameters did not show statistically significant differences.
Aldosterone receptor antagonists reduce or avoid increasing of PSAP and inducing a favorable remodeling of the left ventricle, especially in the IVS in diastolic heart failure patients.
Revista de investigacion clinica; organo del Hospital de Enfermedades de la Nutricion 01/2007; 59(2):103-7. · 0.31 Impact Factor
[show abstract][hide abstract] ABSTRACT: Several studies have reported a direct association between elevated plasma levels of inflammatory cytokines and worse functional class (New York Heart Association [NYHA]) and cardiac function, measured as left ventricular ejection fraction (LVEF). Thalidomide has recently shown to improve LVEF in chronic heart failure patients, accompanied by a marked decrease in plasma levels of tumor necrosis factor alpha (TNF-alpha).
In a randomized prospective open label study of men and women with heart failure (HF) due to ischemic and non-ischemic cardiomyopathy who had systolic dysfunction (LVEF <40%) and NHYA classification, functional classes II and III were assigned to control (without thalidomide, 60 patients) or thalidomide group (20 patients). The initial dose of thalidomide was 100 mg once a day, and it was increased to 100 mg twice a day after a period of 10 days, if the prior dosage was well-tolerated. Demographic characteristics, etiology of HF, prior myocardial infarction, co-morbidities associated were registered and laboratory routine test, TNF-alpha serum levels, and echocardiogram were obtained at the beginning and after 6 months of follow-up.
Clinical status (NYHA) at the end of the follow-up period, improved moderately in both groups. TNF-alpha levels were initially of 5.88 +/- 0.9 and 6.49 +/- 1.82 vs. 6.32 +/- 1.6 and 7.94 +/- 3.8 pg/ml during follow-up, for thalidomide and control groups, respectively. There were non-significant differences in echocardiography variables.
In conclusion, although there is a large amount of information supporting a direct relationship between TNF-alpha and worsening of symptoms and prognosis in patients with HF and recently, the beneficial effect on thalidomide treatment has been suggested, these preliminary observations should be confirmed in a larger prospective study, specially trying to clarify the action mechanisms.
[show abstract][hide abstract] ABSTRACT: Myocardial involvement occurs in about 20% of patients with mixed connective tissue disease. The purpose of this study was to determine the prevalence of conduction disturbances, their association with other manifestations of the disease.
Determine the prevalence of cardiac conduction disturbances in patients with mixed connective tissue disease attended in an institute in Mexico City and their relation with other manifestations of the disease.
One hundred thirteen patients admitted to the Institute with a diagnosis of mixed connective tissue disease were divided into those with conduction disturbances (n = 23) and those without (n = 90). Over a mean follow-up of 10.2 +/- 7.8 years, clinical course, treatment, duration of the disease, types of conduction disturbances and systemic alterations were examined.
There was an overwhelming predominance of women in both groups. Conduction disturbances occurred in about 20% of the patients with mixed connective tissue disease and that was not possible to find significant differences in the outcome of them. As could be expected a significant difference between the two groups was QRS axis, related to anterior hemiblock, the most common conduction alteration observed. During the follow-up one patient death in-group A, but none in group B.
Conduction disturbances were present in 20%; in agree with other authors in the literature. However, did not participate in the outcome of the disease.
Revista de investigacion clinica; organo del Hospital de Enfermedades de la Nutricion 01/2001; 53(4):330-4. · 0.31 Impact Factor
[show abstract][hide abstract] ABSTRACT: Atrial fibrillation (Afib) is clinically the most common arrhythmia. Its main complications are recurrent embolic events and a variable deterioration of functional class. Atrial fibrillation induces changes in cellular ionic channels that self-perpetuate the arrhythmia. The pharmacologic treatment of Afib is directed toward correction of those changes and return to sinus rhythm. It is also intended to maintain adequate heart rates and prevent embolic events through anticoagulation or platelet antiagregation. There are presently several class IC or class III antiarrhythmics available for attempting a return to sinus rhythm. The success rates are irregular, the best achieved with flecainide or propafenone among patients without structural heart disease. Amiodarone is the best choice when there is such a problem. The combination possibilities are huge, so that each case must be individualized. The new class III antiarrhythmics are very effective, but have a relatively high rate of side effects including torsade de pointes. Anticoagulation should be the preferred treatment among the majority of patients, but each case should be individually evaluated. New therapies such as focal or linear catheter ablation techniques, atrial or biatrial programmed stimulation, and atrial cardioverter-defibrillator need longer follow-up and experience to be objectively evaluated, although there are reasons to be optimistic in the future, even if patients need antiarrhythmic support at present. Surgery has high morbi-mortality rates, so it is not the preferred approach.
Gaceta medica de Mexico 137(5):445-58. · 0.13 Impact Factor
[show abstract][hide abstract] ABSTRACT: Determine the myocardial perfusion characteristics in obstructive sleep apnea and its possible role in cardiovascular damage.
Fourteen patients from the Obesity Clinic weighing less than 130 kg underwent myocardial perfusion studies using single photon emission computed tomography with technetium 99m-labeled sestamibi during nighttime polysomnographic recordings. Coronary angiograms were performed on patients with suspect of severe coronary obstruction according nighttime myocardial perfusion studies or pharmacological stress carried out during waking hours.
All 14 patients manifested myocardial perfusion defects during sleep, affecting an average of 5.5 segments/patient, although only 8 presented ischemic ST segment changes and none demonstrated rhythm or conduction disturbances. Angiographic examination of the 10 patients with the most severe perfusion defects did not reveal significant coronary obstruction, and fewer perfusion defects were documented during daytime scintigraphy.
In obese patients with obstructive sleep apnea, myocardial perfusion defects appear to occur with highest frequency and severity during nighttime sleep, justifying further investigation in a larger number of patients with obstructive sleep apnea and more significant obesity.
Revista de investigacion clinica; organo del Hospital de Enfermedades de la Nutricion 55(1):18-25. · 0.31 Impact Factor