Heart failure, chronic 1 blockers

In symptomatic chronic heart failure, beta-blockers are also an essential component of an optimal medical regimen, as demonstrated in several trials (95-98). Currently extended-release metoprolol succinate, carve-dilol, and bisoprolol remain the agents of choice for treatment of patients with chronic ischemic heart disease and NYHA Class II-IV symptomatic heart failure. 

FIGURE 3-1. Treatment algorithm for chronic heart failure. ACE, angiotensin-converting enzyme ARB, angiotensin receptor blocker EF, ejection fraction HF, heart failure LV, left ventricular Ml, myocardial infarction SOB shortness of breath. Table 3-5 describes staging of heart failure. 

Many patients cannot tolerate chronic ACE inhibitor therapy secondary to adverse effects outlined below. Alternatively, the angiotensin receptor blockers (ARBs), can-desartan and valsartan, have been documented in trials to improve clinical outcomes in patients with heart failure.68,69 Therefore, either an ACE inhibitor or candesartan or valsartan are acceptable choices for chronic therapy for patients who have a low ejection fraction (EF) and heart failure following MI. Since more than five different ACE inhibitors have proven benefits in MI while only two ARBs have been studied, the benefits of ACE inhibitors are generally considered a... 

Medications can increase the risk of hyperkalemia in patients with CKD, including angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, used for the treatment of proteinuria and hypertension. Potassium-sparing diuretics, used for the treatment of edema and chronic heart failure, can also exacerbate the development of hyperkalemia, and should be used with caution in patients with stage 3 CKD or higher. 

The most serious side effects early in ACS are hypotension, bradycardia, and heart block. Initial acute administration of //-blockers is not appropriate for patients presenting with decompensated heart failure. However, therapy may be attempted in most patients before hospital discharge after treatment of acute heart failure. Diabetes mellitus is not a contraindication to //-blocker use. If possible intolerance to //-blockers is a concern (e.g., due to chronic obstructive pulmonary disease), a short-acting drug such as metoprolol or esmolol should be administered IV initially. 

In patients with chronic heart failure, the use of digoxin and beta blockers is typically sufficient to control heart rates, and the combination of digoxin with carvedilol has been shown to provide better overall rate control than either of them used alone in heart failure patients [42]. However, if the patient is either intolerant of beta blockers or they fail to... 

Anonymous. A trial of the beta-blocker bucindolol in patients with advanced chronic heart failure, [see comment]. N. Eng. J. Med. 2001 344 1659-67. 

Most of the indications for -blockers concern the -adrenoceptor. This subtype is predominantly present in the heart, mediating all typical cardiac effects like positive inotropy, chronotropy and dro-motropy. The main indications are hypertension, ischemic heart disease, cardiac arrhythmias and some forms of congestive heart failure. The mechanism by which -blocker, when administered chronically, can reduce the blood pressure is not completely understood yet. Most probably several mechanisms. 

Paradoxically, these agents—not positive inotropic drugs—are the first-line therapies for chronic heart failure. The drugs most commonly used are diuretics, ACE inhibitors, angiotensin receptor antagonists, aldosterone antagonists, and blockers (Table 13-1). In acute failure,... 

Ahmed A, Dell Italia LJ. Use of beta-blockers in older adults with chronic heart failure. Am J Med Sci. 2004 328 100-111. 

Erhardt LR. A review of the current evidence for the use of angiotensin-receptor blockers in chronic heart failure. IntJ Clin Pract. 2005 59 571-578. 

In the past, prescription of a diuretic plus digitalis was almost automatic in every case of chronic heart failure, and other drugs were rarely considered. At present, diuretics are still considered as first-line therapy, but digitalis is usually reserved for patients who do not respond adequately to diuretics, ACE inhibitors, and B-blockers (Table 13-1). 

Cohn JN, Tognoni G. A randomized trial of the angiotensin-receptor blocker valsartan in chronic heart failure. N Engl J Med 2001 345 1667-1675. 

Chronic heart failure is typically managed by reduction in physical activity, low dietary intake of sodium (less than 1500 mg sodium per day), and treatment with vasodilators, diuretics and inotropic agents. Drugs that may precipitate or exacerbate CHF—nonsteroidal antiinflammatory drugs (NSAIDs), alcohol, (3-blockers, calcium channel-blockers and some antiarrhythmic drugs—should be avoided if possible. Patients with CHF complain of dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, fatigue, and dependent edema. 

Subsets of the hypertensive population The (3-blockers are more effective for treating hypertension in white than in black patients, and in young patients compared to the elderly. [Note Conditions that discourage the use of 3-blockers (for example, severe chronic obstructive lung disease, chronic congestive heart failure, severe symptomatic occlusive peripheral vascular disease) are more commonly found in the elderly and in diabetics.]... 

Like p-blockers, ACE inhibitors are most effective in hypertensive patients who are white and young. However, when used in combination with a diuretic, the effectiveness of ACE inhibitors is similar in white and black hypertensive patients. Unlike p-blockers, ACE inhibitors are effective in the management of patients with chronic congestive heart failure (see p. 156). ACE inhibitors are now a standard in the care of a patient following a myocardial infarction. Therapy is started 24 hours after the end of the infarction. 

Beta-adrenoceptor blockers. The realisation that the coiuse of chronic heart failure can be adversely affected by activation of the renin-angiotensin-aldosterone and sympathetic nervous systems led to exploration of possible benefit from P-adrenoceptors in a condition where, paradoxically, such drugs can have an adverse effect. Clinical trials have, indeed, shown that bisoprolol, carvedilol or metoprolol lower mortality and decrease hospitalisation when added to diuretics, digoxin and an ACE inhibitor (see below). 

Amlodipine is a long-acting dihydropyridine calcium channel blocker. It has an adverse effects profile similar to those of other dihydropyridines, but at a lower frequency (1). Along with felodipine (2), but unlike other calcium channel blockers, it may also be safer in severe chronic heart failure when there is concurrent angina or hypertension (3). 

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