Biventricular pacing improves clinical behavior and reduces prevalence of ventricular srrhythmia in patients with heart failure

PURPOSE: To analyze the influence of biventricular pacing (BP) on clinical behavior, ventricular arrhythmia (VA) prevalence, and left ventricular ejection fraction (LV EF) by gated ventriculography. METHODS: Twenty-four patients with left bundle branch block (LBBB) and NYHA class III and IV underwent pacemaker implantation and were randomized either to the conventional or BP group, all receiving BP after 6 months. RESULTS: Sixteen patients were in NYHA class IV (66.6%) and 8 were in class III (33.4%). After 1-year follow-up, 14 patients were in class II (70%) and 5 were in class III (25%). Two sudden cardiac deaths occurred. A significant reduction in QRS length was found with BP (p=0.006). A significant statistical increase, from a mean of 19.13 ± 5.19% (at baseline) to 25.33 ± 5.90% (with BP) was observed in LVEF Premature ventricular contraction prevalence decreased from a mean of 10,670.00 ± 12,595.39 SD or to a mean of 3,007.00 ± 3,216.63 SD PVC/24 h with BP (p<0.05). Regarding the hospital admission rate over 1 year, we observed a significant reduction from 60. To 16 admissions with BP (p<0.05). CONCLUSION: Patients with LBBB and severe heart failure experienced, with BP, a significant NYHA class and LVEF improvement. A reduction in the hospital admission rate and VA prevalence also occurred.

Effects of Sibutramine on the Treatment of Obesity in Patients with Arterial Hypertension

OBJECTIVE: To assess the effects of weight reduction with 10mg of sibutramine or placebo on blood pressure during 24 hours (ambulatory blood pressure monitoring), on left ventricular mass, and on antihypertensive therapy in 86 obese and hypertensive patients for 6 months. METHODS: The patients underwent echocardiography, ambulatory blood pressure monitoring, and measurement of the levels of hepatic enzymes prior to and after treatment with sibutramine or placebo. RESULTS: The group using sibutramine had a greater weight loss than that using placebo (6.7% versus 2.5%; p<0.001), an increase in heart rate (78.3±7.3 to 82±7.9 bpm; p=0.02), and a reduction in the left ventricular mass/height index (105±29.3 versus 96.6±28.58 g/m; p=0.002). Both groups showed similar increases in the levels of alkaline phosphatase and comparable adjustments in antihypertensive therapy; blood pressure, however, did not change. CONCLUSION: The use of sibutramine caused weight loss and a reduction in left ventricular mass in obese and hypertensive patients with no interference with blood pressure or with antihypertensive therapy.

Autonomic Modulation of the Heart in Systemic Arterial Hypertension

OBJECTIVE: To analyze the heart rate variability in patients with mild to moderate systemic arterial hypertension. METHODS: Thirty-two healthy (group I) and 70 systemic arterial hypertensive (group II) individuals, divided according to age (40 to 59 and 60 to 80 years old, respectively) and with a similar distribution by sex were studied. Thirty-one had left ventricular hypertrophy (LVH), 22 were overweight, and 16 had Type II diabetes mellitus. Smoking, alcohol ingestion, and sedentary habits were the same between groups. Variability in heart rate was analyzed in the time domain, using standard deviations of normal RR intervals (SDNN) and the differences between maximal brady- and tachycardia (D-BTmax) during sustained inspiration. Analysis of the frequency band of the power spectrum between 0.05 and 0.40 Hz at rest and during controlled respiration was chosen for analysis of the frequency domain. RESULTS: In both time and frequency domains, variables were lower in group II than in group I. Within groups, statistically significant variables were only found for individuals in the 40 to 59 year old group. The presence of LVH, overweight, or diabetes mellitus did not influence the variability in heart rate to a significant extent. CONCLUSION: Variability in heart rate was a valuable instrument for analyzing autonomic modulation of the heart in arterial hypertension. The autonomic system undergoes significant losses in cardio-modulatory capacity, more evident in subjects between 40 and 59 years old. In those over 60 years old, reduced variability in heart rate imposed by aging was not significantly influenced by the presence of systemic arterial hypertension.

Implications of the Hemodynamic Optimization Approach Guided by Right Heart Catheterization in Patients with Severe Heart Failure

OBJECTIVE: To report the hemodynamic and functional responses obtained with clinical optimization guided by hemodynamic parameters in patients with severe and refractory heart failure. METHODS: Invasive hemodynamic monitoring using right heart catheterization aimed to reach low filling pressures and peripheral resistance. Frequent adjustments of intravenous diuretics and vasodilators were performed according to the hemodynamic measurements. RESULTS: We assessed 19 patients (age = 48±12 years and ejection fraction = 21±5%) with severe heart failure. The intravenous use of diuretics and vasodilators reduced by 12 mm Hg (relative reduction of 43%) pulmonary artery occlusion pressure (P<0.001), with a concomitant increment of 6 mL per beat in stroke volume (relative increment of 24%, P<0.001). We observed significant associations between pulmonary artery occlusion pressure and mean pulmonary artery pressure (r=0.76; P<0.001) and central venous pressure (r=0.63; P<0.001). After clinical optimization, improvement in functional class occurred (P< 0.001), with a tendency towards improvement in ejection fraction and no impairment to renal function. CONCLUSION: Optimization guided by hemodynamic parameters in patients with refractory heart failure provides a significant improvement in the hemodynamic profile with concomitant improvement in functional class. This study emphasizes that adjustments in blood volume result in imme-diate benefits for patients with severe heart failure.

Study of Coronary Flow Reserve with Intravenous Use of Microbubbles (Contrast Echocardiography) and Adenosine: Protocol for Clinical Application in Patients Suspected of Having Coronary Heart Disease

OBJECTIVE: To test the feasibility, safety and accuracy of the adenosine protocol in the study of myocardial perfusion with microbubbles contrast echocardiography. METHODS: 81 pts (64 male, 60+11 years) were submitted to contrast echocardiography with PESDA (sonicated solution of albumin 20%-1ml, dextrose 5%-12ml and deca-fluorobutane gas-8ml) to study the myocardial perfusion at rest and after bolus injection of adenosine (6 to 18mg) and to coronary angiography within 1 month each other. For each patient 3 left ventricle perfusion beds were considered (total of 243 territories). 208 territories were analyzed and 35 territories were excluded. PESDA was continuously infused (1-2ml/min), titrated for best myocardial contrast. Triggered (1:1) second harmonic imaging was used. RESULTS: Coronary angiography showed 70 flow limiting (> 75%) lesions and 138 no flow limiting lesions. At rest an obvious myocardium contrast enhancement was seen in at least 1 segment of a territory in all patients. After adenosine injection an unquestionable further increase in myocardial contrast was observed in 136 territories (99%) related to no flow limiting lesions, lasting < 10 s, and a myocardial perfusion defect was detected in 68 territories (97%) related to flow limiting lesions. It was observed only 4 false results. There were no serious complications. CONCLUSION: Myocardial perfusion study with PESDA and adenosine protocol is a practical, safe and accurate method to analyze the coronary flow reserve.

Acute Myocardial Infarction: The First Manifestation of Ischemic Heart Disease and Relation to Risk Factors

OBJECTIVE: To assess the association between cardiovascular risk factors and acute myocardial infarction as the first manifestation of ischemic heart disease, correlating them with coronary angiographic findings. METHODS: We carried out a cross-sectional study of 104 patients with previous acute myocardial infarction, who were divided into 2 groups according to the presence or absence of angina prior to acute myocardial infarction. We assessed the presence of angina preceding acute myocardial infarction and risk factors, such as age >55 years, male sex, smoking, systemic arterial hypertension, lipid profile, diabetes mellitus, obesity, sedentary lifestyle, and familial history of ischemic heart disease. On coronary angiography, the severity of coronary heart disease and presence of left ventricular hypertrophy were assessed. RESULTS: Of the 104 patients studied, 72.1% were males, 90.4% were white, 73.1% were older than 55 years, and 53.8% were hypertensive. Acute myocardial infarction was the first manifestation of ischemic heart disease in 49% of the patients. The associated risk factors were systemic arterial hypertension (RR=0.19; 95% CI=0.06-0.59; P=0.04) and left ventricular hypertrophy (RR=0.27; 95% CI=0,.8-0.88; P=0.03). The remaining risk factors were not statistically significant. CONCLUSION: Prevalence of acute myocardial infarction as the first manifestation of ischemic heart disease is high, approximately 50%. Hypertensive individuals more frequently have symptoms preceding acute myocardial infarction, probably due to ventricular hypertrophy associated with high blood pressure levels.

Consequences of the Prolonged Waiting Time for Patients Candidates for Heart Surgery

OBJECTIVE - To assess mortality and the psychological repercussions of the prolonged waiting time for candidates for heart surgery. METHODS - From July 1999 to May 2000, using a standardized questionnaire, we carried out standardized interviews and semi-structured psychological interviews with 484 patients with coronary heart disease, 121 patients with valvular heart diseases, and 100 patients with congenital heart diseases. RESULTS - The coefficients of mortality (deaths per 100 patients/year) were as follows: patients with coronary heart disease, 5.6; patients with valvular heart diseases, 12.8; and patients with congenital heart diseases, 3.1 (p<0.0001). The survival curve was lower in patients with valvular heart diseases than in patients with coronary heart disease and congenital heart diseases (p<0.001). The accumulated probability of not undergoing surgery was higher in patients with valvular heart diseases than in the other patients (p<0.001), and, among the patients with valvular heart diseases, this probability was higher in females than in males (p<0.01). Several patients experienced intense anxiety and attributed their adaptive problems in the scope of love, professional, and social lives, to not undergoing surgery. CONCLUSION - Mortality was high, and even higher among the patients with valvular heart diseases, with negative psychological and social repercussions.

Can the Cardiopulmonary 6-Minute Walk Test Reproduce the Usual Activities of Patients with Heart Failure?

OBJECTIVE: The 6-minute walk test is an way of assessing exercise capacity and predicting survival in heart failure. The 6-minute walk test was suggested to be similar to that of daily activities. We investigated the effect of motivation during the 6-minute walk test in heart failure. METHODS: We studied 12 males, age 45±12 years, ejection fraction 23±7%, and functional class III. Patients underwent the following tests: maximal cardiopulmonary exercise test on the treadmill (max), cardiopulmonary 6-minute walk test with the walking rhythm maintained between relatively easy and slightly tiring (levels 11 and 13 on the Borg scale) (6EB), and cardiopulmonary 6-minute walk test using the usual recommendations (6RU). The 6EB and 6RU tests were performed on a treadmill with zero inclination and control of the velocity by the patient. RESULTS: The values obtained in the max, 6EB, and 6RU tests were, respectively, as follows: O2 consumption (ml.kg-1.min-1) 15.4±1.8, 9.8±1.9 (60±10%), and 13.3±2.2 (90±10%); heart rate (bpm) 142±12, 110±13 (77±9%), and 126±11 (89±7%); distance walked (m) 733±147, 332±66, and 470±48; and respiratory exchange ratio (R) 1.13±0.06, 0.9±0.06, and 1.06±0.12. Significant differences were observed in the values of the variables cited between the max and 6EB tests, the max and 6RU tests, and the 6EB and 6RU tests (p<0.05). CONCLUSION: Patients, who undergo the cardiopulmonary 6-minute walk test and are motivated to walk as much as they possibly can, usually walk almost to their maximum capacity, which may not correspond to that of their daily activities. The use of the Borg scale during the cardiopulmonary 6-minute walk test seems to better correspond to the metabolic demand of the usual activities in this group of patients.

Prevalence of Cardiac Arrhythmias During and After Pregnancy in Women with Chagas' Disease without Apparent Heart Disease

OBJECTIVE: To evaluate cardiac arrhythmias during and after pregnancy in women with Chagas' disease without apparent heart disease using dynamic electrocardiography. METHODS: Twenty pregnant women with Chagas' disease without apparent heart disease aged 19 to 42 years (26.96 ± 3.6) and a control group of 20 non-chagasic pregnant patients aged 16 to 34 years (22.5 ± 4.8). The patients were submitted to passive hemagglutination and indirect immunofluorescence for the detection of Trypanosoma cruzi evaluation, and electrocardiography, echocardiography and 24-h dynamic electrocardiography. RESULTS: Supraventricular premature depolarizations were observed in 18 (90%) patients and ventricular premature depolarization in 11 (55%) patients of both groups during pregnancy. After delivery, supraventricular premature depolarizations were present in 13 (60%) chagasic patients and in 16 (89.4%) control patients (P<=0.05). Ventricular premature depolarization were observed in 9 (45%) chagasic patients and 11 (57.8%) control patients. CONCLUSION: The prevalence of ventricular premature depolarization was similar for the chagasic and control groups during and after pregnancy. The incidence of supraventricular premature depolarizations was similar in the two groups during pregnancy, while after delivery a predominance was observed in the control group compared to the chagasic group.

Correlations Between the Collagen Content of the Human Left Ventricular Myocardium, Measured by Biochemical and Morphometric Methods

OBJECTIVE: To assess, in myocardium specimens obtained from necropsies, the correlation between the concentration of hydroxyproline, measured with the photocolorimetric method, and the intensity of fibrosis, determined with the morphometric method. METHODS: Left ventricle myocardium samples were obtained from 45 patients who had undergone necropsy, some of them with a variety of cardiopathies and others without any heart disease. The concentrations of hydroxyproline were determined with the photocolorimetric method. In the histologic sections from each heart, the myocardial fibrosis was quantified by using a light microscope with an integrating ocular lens. RESULTS: A median of, respectively, 4.5 and 4.3 mug of hydroxyproline/mg of dry weight was found in fixed and nonfixed left ventricle myocardium fragments. A positive correlation occurred between the hydroxyproline concentrations and the intensity of fibrosis, both in the fixed (Sr=+0.25; p=0.099) and in the nonfixed (Sr=+0.32; p=0.03) specimens. CONCLUSION: The biochemical methodology was proven to be adequate, and manual morphometry was shown to have limitations that may interfere with the statistical significance of correlations for the estimate of fibrosis intensity in the human myocardium.

Assessment of the Cardiovascular Risk and Physical Activity of Individuals Exercising at a Public Park in the City of São Paulo

OBJECTIVE: Physical exercise helps to prevent cardiovascular disorders. Campaigns promoting exercise have taken many people to the parks of our city. The most appropriate exercise for preventing cardiovascular disorders is the aerobic modality; inappropriate exercise acutely increases cardiovascular risk, especially in individuals at higher risk. Therefore, assessing the cardiovascular risk of these individuals and their physical activities is of practical value. METHODS: In the Parque Fernando Costa, we carried out the project "Exercício e Coração" (Exercise and Heart) involving 226 individuals. Assessment of the cardiovascular risk and of the physical activity practiced by the individuals exercising at that park was performed with a questionnaire and measurement of the following parameters: blood pressure, weight, height, and waist/hip ratio. The individuals were lectured on the benefits provided by exercise and how to correctly exercise. Each participant received a customized exercise prescription. RESULTS: In regard to risk, 43% of the individuals had health problems and 7% of the healthy individuals had symptoms that could be attributed to heart disorders. High blood pressure was observed in a large amount of the population. In regard to the adequacy of the physical activity, the individuals exercised properly. The project was well accepted, because the participants not only appreciated the initiative, but also reported altering their exercise habits after taking part in the project. CONCLUSION: Data obtained in the current study point to the need to be more careful in assessing the health of individuals who exercise at parks, suggesting that city parks should have a sector designated for assessing and guiding physical activity.

Late Clinical Outcomes of the Fontan Operation in Patients with Tricuspid Atresia

OBJECTIVE: Evaluation of the long-term clinical results of the Fontan operation in patients with tricuspid atresia. METHODS: A retrospective analysis was made at the Instituto de Cardiologia do Rio Grande do Sul (Institute of Cardiology of Rio Grande do Sul), from August 1980 through January 2000, of 25 patients with a long-term follow-up, out of a series of 36 patients who underwent the Fontan operation or one of its variants due to tricuspid atresia. Their mean age at surgery was 5.4±3.1 years, and their mean weight was 15.8±6.1 kg, the majority of them (63.9%) being males. Four patients underwent the classical Fontan operation, 12 the Kreutzer variant, 6 the Björk variant, 9 total cavopulmonary shunt with a fenestrated tube, and 5 total cavopulmonary shunt with a nonfenestrated tube. RESULTS: The patients were followed-up on an outpatient basis, with a mean long-term survival time of 5.5±4.2 years (50 days to 17.8 years) and a late mortality rate of 8%. Arterial saturation increased from 77.2±18.8% in the preoperative period to 91±6.7% upon the last outpatient visit (p>0.05). At the final check, most (67%) patients were asymptomatic and 87% could tolerate exercise. Ten (40%) patients experienced some kind of complication during the long-term follow-up, such as cardiac arrhythmia, cyanosis, protein-losing enteropathy, neurological events, right heart failure, intolerance to exercise and reoperation. CONCLUSION: The results indicate that, once the immediate postoperative period is over, during which the adaptations to the new circulatory physiology occur, the evolution of patients with tricuspid atresia who underwent the Fontan operation is satisfactory, in spite of a low, yet significant, morbidity.

Neonate Aortic Stenosis: Importance of Myocardial Perfusion in Prognosis

OBJECTIVE: To analyze our experience with percutaneous aortic balloon valvuloplasty in newborn infants with aortic stenosis, emphasizing the extraordinary importance of myocardial perfusion.METHODS: Over a 10-year-period, 21 neonates underwent percutaneous aortic balloon valvuloplasty. Age ranged from 2 to 27 days, weight ranged from 2.2 to 4.1 kg and 19 were males. All patients presented with congestive heart failure that could not be treated clinically. The onset of symptoms in the first week of life occurred in 9 patients considered as having critical aortic stenosis. Severe aortic stenosis occurred in 12 patients with the onset of symptoms in the second week of life.RESULTS: Mortality reached 100% in the patients with critical aortic stenosis. The procedure was considered effective in the 12 patients with severe aortic stenosis. Vascular complications included the loss of pulse in 12 patients and rupture of the femoral artery in 2 patients. Cardiac complications included acute aortic regurgitation in 2 patients and myocardial perforation in one. In an 8.2±1.3-year follow-up, 5 of the 12 patients died (2 patients due to septicemia and 3 patients due to congestive heart failure). Five of the other 7 patients underwent a new procedure and 2 required surgery.CONCLUSION: Percutaneous aortic valvuloplasty in neonates is not an effective procedure in the 1st week of life, because at this age the common presentation is cardiogenic shock. It is possible that, in those patients with critical aortic stenosis, dilation of the aortic valve during fetal life may change the prognosis of its clinical outcome.

Trends of the Risk of Death due to Circulatory, Cerebrovascular, and Ischemic Heart Diseases in 11 Brazilian Capitals from 1980 to 1998

OBJECTIVE: To assess the trends of the risk of death due to circulatory (CD), cerebrovascular (CVD), and ischemic heart diseases (IHD) in 11 Brazilian capitals from 1980 to 1998. METHODS: Data on mortality due to CD, CVD and IHD were obtained from the Brazilian Health Ministry, and the population estimates were calculated by interpolation with the Lagrange method based on census data from 1980 and 1991 and the population count of 1996. The trends were analyzed with the multiple linear regression method. RESULTS: CD showed a trend towards a decrease in most capitals, except for Brasília, where a mild increase was observed. The cities of Porto Alegre, Curitiba, Rio de Janeiro, Cuiabá, Goiânia, Belém, and Manaus showed a decrease in the risk of death due to CVD and IHD, while the city of Brasília showed an increase in CVD and IHD. The city of São Paulo showed a mild increase in IHD for individuals of both sexes aged 30 to 39 years and for females aged 40 to 59 years. In the cities of Recife and Salvador, a reduction in CD was observed for all ages and both sexes. In the city of Recife, however, an increase in IHD was observed at younger ages (30 to 49 years), and this trend decreased until a mild reduction (-4%) was observed in males ³ 70 years. CONCLUSION: In general, a reduction in the risk of death due to CD and an increase in IHD were observed, mainly in the cities of Recife and Brasília.

Benefits of exercise training in the treatment of heart failure: study with a control group

OBJECTIVE: Exercise training programs have been proposed as adjuncts to treatment of heart failure. The effects of a 3-month-exercise-training-program with 3 exercise sessions per week were assessed in patients with stable systolic chronic heart failure. METHODS: We studied 24 patients with final left ventricle diastolic diameter of 70±10mm and left ventricular ejection fraction of 37±4%. Mean age was 52±16 years. Twelve patients were assigned to an exercise training group (G1), and 12 patients were assigned to a control group (G2). Patients underwent treadmill testing, before and after exercise training, to assess distance walked, heart rate, systolic blood pressure, and double product. RESULTS: In G2 group, before and after 3 months, we observed, respectively distance walked, 623±553 and 561± 460m (ns); peak heart rate, 142±23 and 146± 33b/min (ns); systolic blood pressure, 154±36 and 164±26 mmHg (ns); and double product, 22211± 6454 and 24293±7373 (ns). In G1 group, before and after exercise, we observed: distance walked, 615±394 and 970± 537m (p<0.003) peak heart rate, 143±24 and 143±29b/min (ns); systolic blood pressure, 136±33 and 133±24 mmHg (ns); and double product, 19907± 7323 and 19115±5776, respectively. Comparing the groups, a significant difference existed regarding the variation in the double product, and in distance walked. CONCLUSION: Exercise training programs in patients with heart failure can bring about an improvement in physical capacity.