Management of common arrhythmias: Part II. Ventricular arrhythmias and arrhythmias in special populations.

In patients without established cardiac disease, the occurrence of premature ventricular complexes without sustained ventricular tachycardia is more an annoyance than a medical risk, and treatment is not required. In contrast, patients with established heart disease and premature ventricular complexes have a higher likelihood of developing ventricular tachycardia or fibrillation. These patients should be treated with a beta blocker or class I antiarrhythmic drug. Treatment of arrhythmias in pregnant women is rarely needed. When treatment is required, amiodarone should be avoided, and beta blockers should be used with caution, because these agents have been associated with fetal growth retardation. The most important rhythm abnormality in athletes is ventricular tachycardia associated with hypertrophic cardiomyopathy. If the presence of the disease is confirmed by echocardiography, beta-blocker therapy is necessary, and these patients should be limited to participation in nonstrenuous sports. Acute arrhythmias in children with Wolff-Parkinson-White syndrome can be treated with adenosine. Radiofrequency ablation of the accessory pathway can provide long-term control.