Factors causing arrhythmias in chronic congestive heart failure.

Severe congestive heart failure (CHF) is a common syndrome with a high mortality rate (about 50% in 1 year among patients with symptoms at rest). Severity of left ventricular dysfunction is the most important adverse prognostic factor. Serious arrhythmias are common in CHF and also increase the mortality rate. Sudden death is the mode of death in about 40% of patients with severe heart failure. Multiple factors contribute to arrhythmias in CHF, including left ventricular dysfunction, myocardial ischemia, catecholamines, electrolyte disturbances, and drugs used to treat the heart failure. Minimizing or correcting these influences may be important in reducing serious arrhythmias. Antiarrhythmic drugs may be important in reducing the incidence of sudden death among patients with severe heart failure, although this has not yet been proved.