![]() ![]() This can occur even in patients who have no previous history of coronary symptoms. In some cases there may be the precipitation of serious ventricular tachyarrhythmia, including sudden cardiac death. The most important concern with beta blocker withdrawal is the exacerbation of ischemic symptoms, including the precipitation of an acute myocardial infarction, in patients with known coronary artery disease. īeta blocker withdrawal - Acute withdrawal of a beta blocker can lead to substantial morbidity and even mortality. Compounds with ISA may cause less impairment of AV conduction. Use of a beta blocking drug can therefore lead to a serious bradyarrhythmia in patients with an underlying complete or partial AV conduction defect (ie, second or third degree AV block), especially if the patient is also receiving another agent that impairs AV nodal conduction such as digoxin or a calcium channel blocker. Nevertheless, all beta blockers are relatively contraindicated in patients with symptomatic bradycardia that may be associated with sinus node dysfunction, especially if there is a further reduction in rate, unless an artificial pacemaker is present.īeta blockers also depress conduction through the atrioventricular (AV) node, potentially causing heart block. This effect is less prominent with drugs with ISA. Negative chronotropic effects - Slowing of the resting heart rate and the development of sinus bradycardia is a normal response to treatment with a beta blocker. One study that reviewed data from HF trials reported between 19 found that, although beta blockers were associated with these side effects, the absolute increase in symptoms was small and did not necessitate withdrawal of drug therapy. (See "Treatment and prognosis of heart failure with preserved ejection fraction" and "Primary pharmacologic therapy for heart failure with reduced ejection fraction".)Īnother concern about beta blockers in patients with HF is the occurrence of other symptoms, including dizziness due to hypotension and bradycardia. Furthermore, long-term therapy with beta blockers is often beneficial in such patients, improving survival in patients with systolic heart failure and improving diastolic function in patients with diastolic heart failure. As an example, worsening of heart failure was observed in only 6 percent of patients with chronic heart failure who were being treated with carvedilol . ![]() ĭespite these concerns, only a minority of patients with stable heart failure deteriorate after the initiation of beta blocker therapy. On the other hand, drugs with intrinsic sympathetic activity (ISA), such as pindolol, may be less likely to impair myocardial function. Increased peripheral vascular resistance, induced by nonselective beta blockers, also may contribute to the decline in myocardial function in this setting. (See "Pharmacologic therapy of heart failure with reduced ejection fraction: Mechanisms of action", section on 'Beta blockers'.) However, patients already receiving beta blockers can be continued on this therapy if there is decompensated heart failure. ![]() Hence, beta blockers should not be administered as new therapy until after heart failure is compensated. However, beta blockers may exacerbate symptoms in patients with acute decompensated heart failure or in those with preexisting myocardial dysfunction and borderline compensation, since the maintenance of cardiac output in such patients depends in part upon sympathetic drive. Heart failure - Beta blockers are an important component of long-term therapy for patients with chronic heart failure and reduced left ventricular systolic function, as these drugs reduce the detrimental effects of excess chronic catecholamine stimulation. (See "Beta blocker poisoning" and "Choice of drug therapy in primary (essential) hypertension" and "Acute myocardial infarction: Role of beta blocker therapy" and "Primary pharmacologic therapy for heart failure with reduced ejection fraction".)ĪDVERSE CARDIAC EFFECTS DUE TO BETA BLOCKADE - Major cardiac effects caused by beta blockade include the precipitation or worsening of congestive heart failure, and significant negative chronotropy. Beta blocker intoxication (overdose) and the clinical use of these drugs for the treatment of arrhythmias, hypertension, myocardial infarction, and heart failure are discussed separately. The major side effects associated with the use of beta blockers will be reviewed here. ![]() Other reactions apparently unrelated to beta blockade can occur, but they are uncommon. Many signs and symptoms can therefore be induced because the beta receptors affect multiple metabolic and physiologic functions. INTRODUCTION - Most of the major adverse effects of beta blocking drugs result from beta-adrenoreceptor blockade. ![]()
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