Amiodarone in congestive heart failure

Originally developed as an antianginal agent, amiodarone was soon found to have antiarrhythmic properties and to be a non-competitive inhibitor of alpha and beta-adrenergic receptors. Many trials studying the use of amiodarone in patients with heart failure have now been performed and are reviewed in this article. The trials appear to show that amiodarone possesses significant antiarrhythmic activity, even in heart failure patients. The drug appears to be well tolerated and proarrhythmia is uncommon. Based on the findings of a large Argentinian randomised trial (GESICA) and the Congestive Heart Failure Survival Trial of Antiarrhythmic Therapy (CHF STAT), it would appear there is a role for amiodarone in patients with non-ischaemic cardiomyopathy, but prospective studies are required to confirm this. The benefit of amiodarone in patients with non-ischaemic cardiomyopathy might be related to the beta-blocking effect that is seen with the use of conventional beta-blockers. Further studies, including the Sudden Cardiac Death Heart Trial (SCD HeFT), should help determine the role of amiodarone in heart failure patients.     

Female patients with congestive heart failure: how they conceive their life situation

Congestive heart failure (CHF) is a significant health problem for women, particularly elderly women. The risk factors for heart failure appear to be different in women than in men, with hypertension and diabetes playing a greater role in women and ischaemic heart disease a greater role in men. The aim of this study was to describe, from a nurse's perspective, how female patients with CHF conceive their life situation. Interview questions were designed with a focus on five dimensions: biophysical, socio-cultural, emotional, intellectual and spiritual-existential. A qualitative method was used with a phenomenographic approach, as this approach examines aspects of the surroundings as they are conceived. Five categories emerged in the results: feeling content, feeling a sense of support, feeling a sense of limitation, feeling anxiety and feeling powerless. A sense of limitation regarding working capacity and being able to support those in their surroundings causes patients with CHF to experience anxiety due to feeling insecure about themselves and in relation to their surroundings. This may result in feelings of worthlessness in women with CHF, both concerning their own capacity and the fact that they feel they are a burden to those around them. Through nursing intervention, these patients can receive help to break this vicious circle of feeling limited and powerless. This can be done by encouraging them to verbalize their feelings and set realistic goals and expectations, and by increasing their knowledge and that of their families concerning CHF and its symptoms, with a focus on self-care and existing possibilities. These measures will make it easier for women with CHF to maintain a hopeful perspective and a sense of control, competence, and self-esteem.     

A randomized crossover trial of levodopa in congestive heart failure

BACKGROUND: The short- and long-term effects of levodopa (L-dopa), an oral dopaminergic prodrug, were assessed in patients with severe left ventricular dysfunction. METHODS AND RESULTS: Initially, 26 patients were included in the study group. After clinical, radiographic, and radionuclide examination, each patient underwent right heart catheterization (Swan-Ganz thermodilution catheter). Plasma noradrenaline levels were measured. In two patients, a favorable hemodynamic response to L-dopa was not observed, another two required permanent pacemaker implantation. These four patients were excluded from the study. Two patients required permanent pacemaker implantation. The remaining 22 patients with favorable hemodynamic response to L-dopa (increase in cardiac index, stroke volume index, reduction in total systemic resistance) were randomized in a nonblinded fashion to the conventional (11 patients) or conventional plus L-dopa (11 patients) treatment groups. During the study period, two patients, one from each group, died. They were excluded from the analysis. The final analyzed study group consisted of 20 men, aged 33-69, in New York Heart Association functional class IV (9 patients) and III (11 patients). The cause of congestive heart failure was primary dilated cardiomyopathy in 11 patients and ischemic heart disease in 9 patients. After 3 months' treatment, all patients were crossed over. Clinical, radiographic, radionuclide, and hemodynamic evaluation was repeated at the end of the 3-month treatment period. After 3 months of therapy with L-dopa in each group (covariance analysis), there was improvement in clinical, radiographic (relative heart volume, -128 mL/m2), radionuclide (left ventricular ejection fraction, +4.6; right ventricular ejection fraction, +4.8%), hemodynamic (mean pulmonary wedge pressure, -8 mmHg; total systemic resistance, -1.8 Wu; total pulmonary resistance, -3.5 Wu), and neurohumoral (noradrenaline, -218 pg/mL) measures. CONCLUSIONS: The addition of L-dopa to conventional therapy has beneficial short- and long-term effects in patients with severe left ventricular dysfunction.     

Therapy of congestive heart failure in elderly persons

LVEF should be measured in all elderly persons with CHF Underlying causes and precipitating causes of CHF should be treated. Persons with CHF associated with abnormal LVEF should be treated with a low sodium diet, diuretics, and ACE inhibitors. If CHF persists, digoxin should be added. If CHF still persists, isosorbide dinitrate plus hydralazine should be added. If CHF still persists, a beta blocker should also be added. However, calcium channel blockers should not be used. Persons with CHF associated with normal LVEF should be treated with a low sodium diet, diuretics, and ACE inhibitors. If CHF persists, a beta blocker, isosorbide dinitrate plus hydralazine, or a calcium channel blocker should be added to the therapeutic regimen. If sinus rhythm is present, digoxin should not be used. Persons with CHF and abnormal or normal LVEF unable to tolerate ACE inhibitors should be treated with losartan.     

Decrease of cardiac chaos in congestive heart failure

The electrical properties of the mammalian heart undergo many complex transitions in normal and diseased states. It has been proposed that the normal heartbeat may display complex nonlinear dynamics, including deterministic chaos, and that such cardiac chaos may be a useful physiological marker for the diagnosis and management of certain heart trouble. However, it is not clear whether the heartbeat series of healthy and diseased hearts are chaotic or stochastic, or whether cardiac chaos represents normal or abnormal behaviour. Here we have used a highly sensitive technique, which is robust to random noise, to detect chaos. We analysed the electrocardiograms from a group of healthy subjects and those with severe congestive heart failure (CHF), a clinical condition associated with a high risk of sudden death. The short-term variations of beat-to-beat interval exhibited strongly and consistently chaotic behaviour in all healthy subjects, but were frequently interrupted by periods of seemingly non-chaotic fluctuations in patients with CHF. Chaotic dynamics in the CHF data, even when discernible, exhibited a high degree of random variability over time, suggesting a weaker form of chaos. These findings suggest that cardiac chaos is prevalent in healthy heart, and a decrease in such chaos may be indicative of CHF.     

Learning needs of congestive heart failure patients

Congestive heart failure (CHF) affects approximately one-half million Canadians and five million Americans. Patient education is a vital component of nursing care of this population, with the goals of improving the CHF patient's quality of life, minimizing symptoms and hospital admissions, and reducing length of hospital stay. A review of the literature related to the educational needs of CHF patients reveals minimal research. The purpose of this study was to compare the perceived learning needs of CHF patients by patients and nurses, and to identify existing gaps between their perceptions. Fifty (50) CHF patients and 47 cardiac nurses were surveyed using a modified version of the CHF Patient Learning Needs Inventory developed by Hagenhoff et al. This instrument measured the importance of specific learning topics within the categories of anatomy and physiology, medications, diet, risk factors, activity, psychological factors, and other pertinent information. The results indicated that both groups found most information "moderately" to "very" important to learn. The patients generally rated all information items higher than nurses did. The most significant finding was that the nurses rated the diet category as second in importance, while the patients rated it last. The results from the study will be incorporated into a needs-based educational program for CHF patients.     

Calcium antagonists and sympathetic activity in congestive heart failure

OBJECTIVE: To review the sympathetic abnormalities occurring in heart failure, their pathophysiological importance and clinical relevance, and the effects of drug treatment, with particular reference to calcium antagonists. SYMPATHETIC ACTIVATION IN HEART FAILURE: Indirect and direct approaches to study sympathetic function in humans have documented conclusively that sympathetic activation represents a hallmark of cardiac failure syndrome. Evidence indicates that sympathetic overactivity is associated with, and probably caused by, a baroreflex impairment and that it has adverse effects on patients' prognosis and survival. GOALS OF DRUG TREATMENT IN CONGESTIVE HEART FAILURE: In the past, drug treatment in heart failure was aimed at improving patients' survival by ameliorating cardiac hemodynamics. It is now established that a major goal of therapeutic intervention is also to reduce sympathetic activation characterizing heart failure. CALCIUM ANTAGONISTS IN HEART FAILURE: Studies with short-acting calcium antagonists show that they enhance sympathetic activation and that this has an adverse effect on patients' survival. In contrast, third generation calcium antagonists such as amlodipine, which have a slow onset and long duration of action, do not adversely affect sympathetic function and reflex cardiovascular control. Indeed, evidence suggests calcium antagonists with this profile may exert favorable clinical effects.     

Exercise-related ventilatory abnormalities and survival in congestive heart failure

This retrospective study of 104 New York Heart Association class 1 to 4 heart failure patients undergoing exercise stress testing with gas exchange analysis demonstrated that the ventilatory equivalent for carbon dioxide at anaerobic threshold is useful in determining prognosis in patients with severe congestive heart failure, particularly when used in combination with peak exercise oxygen consumption. A ventilatory equivalent for carbon dioxide >50 and peak oxygen consumption < or =15.0 ml/kg/min defines a very high-risk patient group who should be prioritized for transplantation.     

A placebo-controlled study of growth hormone in patients with congestive heart failure

AIM: Experimental data in heart failure models and an open trial of seven patients with idiopathic dilated cardiomyopathy have suggested beneficial effects of growth hormone on cardiac function. The aim of the present study was to evaluate growth hormone effects on cardiac function in a placebo-controlled study. METHODS: Twenty two patients with congestive heart failure of different aetiologies in NYHA II and III and an echocardiographic ejection fraction <0.45 were studied in a 3 month double-blind placebo-controlled study with growth hormone added to optimal heart failure therapy. Patients received either placebo (n=11) or recombinant human growth hormone (n=11) in an initial dose of 0.1 IU x kg(-1) week(-1) for 1 week, and thereafter 0.25 IU x kg(-1) week(-1) for the rest of the treatment period. Cardiac function was assessed by equilibrium radionuclide angiography and Doppler echocardiography. Functional capacity was evaluated by computerized bicycle exercise electrocardiography. RESULTS: Recombinant human growth hormone had no significant effect on systolic or diastolic cardiac function, exercise capacity or neuroendocrine activation. In addition, there was no overall improvement in functional class or dyspnoea grade. Insulin-like growth factor-I significantly increased demonstrating that the growth hormone had an endocrine effect. CONCLUSION: This is the first double-blind and placebo-controlled study of the administration, over 3 months, of recombinant human growth hormone in patients with congestive heart failure of different aetiologies. The treatment was safe and without serious side effects. However, no beneficial effects on cardiac function or structure could be detected.     

Correlates of outcomes in patients with congestive heart failure

This study relates components of care, including patient characteristics, degree of initial morbidity, and process of care, to patient outcomes. One hundred twenty-two adults who were being treated for congestive heart failure by a sample of physicians in Fort Wayne, Indiana were studied. Data were obtained on the patients' personal characteristics; degree of illness at the beginning of the six-month study period; process measures (physician awareness, communication, medication use, therapeutic management, patient satisfaction, and utilization of services); and level of activity and symptoms at the end of the study period. These components were quantified and subjected to correlation and regression analysis. The largest and most significant predictors of outcome status were measures of initial disease status. Process variables were strongly and significantly associated with outcome only in a group of patients who were minimally symptomatic initially. The lack of an overall association between process of medical care and patient outcome cannot be generalized beyond these patients with congestive heart failure. A similar approach of dissection, quantification, and analysis of components of care, however, can be used to explore a possible relationship in other conditions and care delivery settings.     

Effects of dichloroacetate in patients with congestive heart failure

BACKGROUND: Conventional approaches to management of congestive heart failure (CHF) rely on drugs that increase myocardial contractility or reduce ventricular afterload. These approaches often improve cardiac symptoms and survival, but may be associated with significant deleterious effects. An alternative approach is to enhance myocardial energy production. Dichloroacetate (DCA) stimulates pyruvate dehydrogenase activity and accelerates aerobic glucose, pyruvate, and lactate metabolism in myocardial cells. These alterations would be expected to improve myocardial function. HYPOTHESIS: The purpose of the investigation was to assess the efficacy of DCA in patients with left ventricular systolic dysfunction and to examine the mechanism by which improvement occurs. METHODS: A total of 25 patients (16 men, 9 women; age range 31-72 years, mean 59) with CHF and ejection fraction < or = 40% received an intravenous infusion of 50 mg/kg DCA over 15 min. Indices of systolic and diastolic function were obtained by two-dimensional and Doppler echocardiography performed at baseline, 30 min, and 60 min following completion of DCA infusion. RESULTS: Baseline ventricular ejection fraction was 27.3 +/- 9.1%; 17 patients (68%) had nonischemic cardiomyopathy. Heart rate increased after DCA infusion from 73.9 +/- 14.5 to 79.2 +/- 14.9 beats/min at 60 min; p = 0.02. Left ventricular diastolic and systolic volumes increased at 30 min compared with baseline (248.7 +/- 98.1 vs. 259.6 +/- 99.6; p = 0.04, and 180.1 +/- 80.4 vs. 192.2 +/- 84.9; p = 0.002, respectively), but stroke volume (49.2 +/- 19.1 vs. 48.9 +/- 18.1; p = 0.9) and ejection fraction (27.3 +/- 9.1 vs. 25.7 +/- 9.8; p = 0.2) were unchanged. Indices of diastolic function were also unchanged. CONCLUSION: Dichloroacetate infusion in patients with CHF is not associated with improvement in noninvasively assessed left ventricular function.     

Ace inhibitors: treatment of congestive heart failure

Nasal passage geometry was measured by acoustic rhinometry in 8 healthy medical students (5 males and 3 females, 21-29 years old; mean age 24 years) after 6 min in different postures of head and body. The minimum cross-sectional area (A-min) and volume between the nostril and 7 cm posteriorly were measured on both sides. When changing from sitting to horizontal the total airway dimension (i.e., the sum of A-min for the two sides) decreased by about 16% (Mean +/- SD = 0.19 +/- 0.14 cm2), and when standing up it increased by about 12% (0.14 +/- 0.13 cm2). A-min seemed more sensitive than volume to detecting postural changes. Including the variation between the cavities, the coefficient of variation (CV = SD/Mean) for area was 24.8 +/- 6.7 and for volume 22.4 +/- 6.4 for the 8 subjects. For the total nasal airway passage the corresponding figures were 12.9 +/- 3.9 and 10.9 +/- 5.5. These figures are considerably higher than for subjects measured only in the sitting position under comparable circumstances. In conclusion, our findings indicate a composite response of the nasal cavity mucosa to both systemic (hydrostatic) and local conditions, probably induced by vascular and cutaneous reflexes. These factors must be taken into account in studies of environmental, clinical, and pharmacological conditions.     

Intestinal "bioavailability" of solutes and water: we know how but not why

Only minimal quantities of ingested and normally secreted solutes and water are excreted in the stool. This near 100% bioavailability means that the diet and kidneys are relatively more important determinants of solute, water and acid-base balance than the intestine. Intestinal bioavailability is based on excess transport capacity under normal conditions and the ability to adapt to altered or abnormal conditions. Indeed, the regulatory system of the intestine is as complex, segmented and multi factorial as in the kidney. Alterations in the rate and intestinal site of absorption reflect this regulation, and the diagnosis and treatment of various clinical abnormalities depend on the integrity of intestinal absorptive processes. However, the basis for this regulation an bioavailability are uncertain. Perhaps they had survival value for mammals, a phylogenic class that faced the twin threats of intestinal pathogens and shortages of solutes and water.