Congestive heart failure drugs, specific

ACE inhibitors do not completely block aldosterone synthesis. Since this steroid hormone is a potent inducer of fibrosis in the heart, specific antagonists, such as spironolactone and eplerenone, have recently been very successfully used in clinical trials in addition to ACE inhibitors to treat congestive heart failure [5]. Formerly, these drugs have only been applied as potassium-saving diuretics in oedematous diseases, hypertension, and hypokalemia as well as in primary hyperaldosteronism. Possible side effects of aldosterone antagonists include hyperkalemia and, in case of spironolactone, which is less specific for the mineralocorticoid receptor than eplerenone, also antiandrogenic and progestational actions. 

Answer This patient has congestive heart failure from long-standing hypertension. In addition, the patient has compromised liver function, limiting the choice of drug. Drugs that inhibit the renin-angiotensin system, specifically ACE inhibitors, are... 

Myocardial cell membrane ATPase, the enzyme present in heart muscle, is the site of action of the cardiac steroid glycosides, which have a specific action on the heart muscle. These drugs increase the force of contraction of the muscle (positive inotropic effect) as well as its conductivity and automaticity. They are also valuable in treating congestive heart failure, in which the circulatory needs of organs are no longer satisfied, and heart arrhythmias, in which the rhythm of the cardiac contractions is upset. The effect of the drug is that the force of contraction increases and the heart rate is slowed (chronotropic effect). Consequently, the cardiac output is elevated while the size of the heart decreases. 

Dopamine and dobutamine are sometimes used to stimulate the heart in cases of acute or severe heart failure (see Chapter 20). Dopamine and dobutamine exert a fairly specific positive inotropic effect, presumably through their ability to stimulate beta-1 receptors on the myocardium.60 Other beta-1 agonists (epinephrine, prenalterol, etc.) will also increase myocardial contractility, but most of these other beta-1 agonists will also increase heart rate or have other side effects that prevent their use in congestive heart failure. Dopamine and dobutamine are usually reserved for patients with advanced cases of congestive heart failure who do not respond to other positive inotropic drugs (e.g., digitalis).6,72... 

Edema and specific drugs for its treatment have long been problems of the physician and of the chemist interested in medicinal products. Digitalis and the many related cardiac glycosides were the first effective agents for the treatment of dropsy associated with congestive heart failure. However, it was soon recognized that the mobilization of the excess tissue fluid associated with this condition was due to a primary action on the heart with improved cardiovascular hemodynamics and only secondarily to an action upon the kidney. 

On the basis of this report, and on reports of studies in animals and from the known risks associated with the concurrent use of beta blockers (see Disopyramide -i- Beta blockers , p.252), the UK manufacturer warns about combining disopyramide and other drugs [such as verapamil] that may have additive negative inotropic effects. However, they do point out that in some specific circumstances combinations of antiarrhythmie drugs (they specifically name digoxin, beta blockers and verapamil for the control of atrial fibrillation) may be beneficial. They note that severe hypotension caused by disopyramide has usually been associated with cardiomyopathy or uncompensated congestive heart failure. However, the US manufacturer advises that until more data is available, disopyramide should not be given within 48 hours before or 24 hours after verapamil. ... 

The electrophysiology test may be useful for specific clinical situations. The electrophysiology test may be useful for patients with wide complex tachycardia of unclear mechanism (76) and for patients with syncope and impaired left ventricular function or structural heart disease (76). Examples include a patient with left ventricular dysfunction and a recent non-Q-wave myocardial infarction who has suffered a sustained arrhythmia near the time of the acute myocardial infarction and a patient who has a cardiac arrest after cardiac surgery, in the throes of acute congestive heart failure, or during infusion of an inotropic drug. 

Specific antiarrhythmic drug therapy has been advocated for patients who are at high risk for arrhythmic death, SCD, and total mortality, as standard therapies mentioned are limited in their ability to reduce total mortality in high-risk populations. Several randomized, multicenter antiarrhythmic drug trials have been completed (116-124). Antiarrhythmic drugs used in the post myocardial infarction period or in association with congestive heart failure have not been shown to provide benefit. They may also cause harm. 

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