Digoxin use in congestive heart failure. Current status.

The use of digitalis in congestive heart failure with normal sinus rhythm is still debated. While older uncontrolled, withdrawal studies from 1969 to 1983 provided incomplete data, with poorly documented clinical status and poor haemodynamic and exercise data, some patients did improve clinically when digitalis treatment was utilised. Randomised, double-blind, placebo-controlled trials from 1977 to 1991 were of better quality but still short in duration, with small sample sizes and still with incomplete haemodynamic and exercise data. In 1993, the Prospective Randomised Study of Ventricular Failure and Efficacy of Digoxin (PROVED) and Randomised Assessment of Digoxin on Inhibitors of the Angiotensin-Converting Enzyme (RADIANCE) study, followed in 1997 by the Digitalis Investigation Group (DIG) trial, documented that digoxin prevents clinical deterioration and hospitalisations, and improves exercise tolerance and left ventricular function, but has no effect on survival. A substudy of the DIG trial showed no detrimental effect of digoxin on survival in patients with ejection fraction (EF) of > 45%, i.e. left ventricular (LV) diastolic dysfunction. Therefore, digoxin appears to be the first inotrope with no detrimental effect on survival in heart failure. In addition, the neurohormonal effect of digoxin has been documented, and is possibly present with dosages even lower than 0.25 mg. Finally, it has been determined that patients with only mild heart failure do obtain documented benefit from administration of this drug.

A cardiologist's perspective on evolving concepts in the management of congestive heart failure.

The conceptual framework for treatment of congestive heart failure has changed dramatically in the past 30 years. The 1950s and 1960s were characterized by manipulation of the left ventricular function curve by digitalis and diuretics. The 1970s focused on relief of symptoms by afterload reduction with vasodilators. Then stimulation of cardiac output with inotropes was shown to relieve symptoms, but patients died sooner. Now the focus is on the neurohumeral milieu and methods to counteract excess renin-angiotensin and sympathetic nervous system stimulation. Angiotensin-converting enzyme inhibitors are the drugs of choice because they also improve survival, but beta-blockers are becoming popular. The effect of molecular cardiology on practice guidelines for congestive heart failure is yet to be seen.

Adjunctive medical therapy for acute myocardial infarction.

Physicians should consider oxygen, morphine, nitrates, beta blockers, and aspirin as the foundation of early adjunctive treatment of acute myocardial infarction. An angiotensin-converting enzyme (ACE) inhibitor should be considered after 72 hours of adjunctive treatment. Intravenous heparin therapy is useful in certain subsets of patients, and intravenous magnesium therapy shows promise. With the exception of beta blockers, prophylactic antiarrhythmic agents are currently not indicated. We predict that combination therapy with aspirin, a beta blocker, and an ACE inhibitor will assume an ever-increasing role in treatment of myocardial infarction.

Antihypertensive therapy. Current issues and challenges.

Choosing antihypertensive agents that protect patients against cardiovascular and other complications is a growing trend in the treatment of mild to moderate hypertension. Calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors are favored because they have neutral or positive effects on lipid levels and insulin resistance. The alpha 1 blockers, especially doxazosin mesylate (Cardura), are enjoying a resurgence in popularity because they have a beneficial effect on lipid levels. In terms of preserving patients' quality of life, the ACE inhibitors in particular have been shown to have a positive impact. It has been shown that systolic hypertension in elderly patients should definitely be treated, but the most appropriate agent has yet to be defined. Therapy should be tailored to the individual. The following questions should be considered when choosing an antihypertensive agent: (1) What are its side effects (especially metabolic ones)? (2) Does it require only once- or twice-a-day dosing? (3) Does it cause regression of left ventricular hypertrophy? (4) Does it prevent death from coronary artery disease? (5) How will it affect quality of life? (6) How much does it cost? The goal of therapy should be to provide adequate blood pressure control throughout the day, enhance compliance, and protect the heart, brain, and kidneys without adversely affecting metabolic state.

A cardiology patient simulator for continuing education of family physicians.

"Harvey," the cardiology patient simulator (CPS), is the result of a new type of simulation technology that allows for repetitive practice of bedside cardiology skills and provides feedback to the learner. "Harvey" is able to realistically simulate an essentially unlimited number of both common and rare cardiac disease. This report describes the use of the CPS in continuing medical education programs conducted for members of the American Academy of Family Physicians. Cardiovascular disorders constitute a significant percentage of the practice of family physicians. The CPS teaching system has great potential for helping them keep their cardiovascular diagnostic skills current and for promoting better understanding of recent advances in the diagnosis and treatment of heart disease. The participants in this study were nearly unanimous in their feeling that the CPS accurately simulates cardiology bedside findings and is a valuable teaching tool with which they would like to again be taught in the future.

Clinical decision-making with treadmill testing and thallium 201.

Fifty patients were prospectively evaluated for myocardial ischemia utilizing treadmill testing and thallium-201 imaging. By coronary angiography, 43 had significant coronary stenosis and seven were normal. The sensitivity, specificity, accuracy and predictive value of treadmill testing alone (81 per cent, 71 per cent, 80 per cent and 95 per cent) did not statistically differ from that of thallium-201 imaging (70 per cent, 86 per cent, 72 per cent and 97 per cent). Combined treadmill testing and thallium-201 imaging (84 per cent, 71 per cent, 80 per cent and 98 per cent) did not significantly affect the results of treadmill testing alone. Thallium-201 imaging failed to identify a number of patients with high risk lesions. The high prevalence of disease, the presentation of typical angina, preselection bias, multiple lead monitoring and exclusion of patients with abnormalities on the resting electrocardiogram probably accounted for failure of thallium-201 imaging to improve the results obtained with treadmill testing. The use of thallium-201 imaging in certain subsets of patient (resting electrocardiographic abnormalities, nondiagnostic treadmill testing, atypical chest pain or asymptomatic patients with abnormalities on treadmill testing) may be of value. However, the use of thallium-201 imaging as a routine screening procedure for myocardial ischemia in patients with typical angina, without due consideration of the prevalence of the disease in the population, is not justified.

Isolated gonococcal pulmonary valve endocarditis: diagnosis by echocardiography.

The perplexing clinical course of a 23-year-old black male with isolated gonococcal pulmonary valvular endocarditis is presented. M-mode echocardiography provided the first clue to the presence of pulmonary valvular vegetations and the proper diagnosis. Since Neisseria gonorrhea appears to have a particular affinity for the pulmonary valve, the presence of isolated pulmonary valvular endocarditis should raise the strong possibility that Neisseria gonorrhea is the offending organism. This case report of pulmonary valvular vegetations detected by echocardiography strongly emphasizes that all four cardiac valves must be visualized in order to rule out the presence of echocardiographically detectable valvular vegetations.