Current approaches to evaluation and management of patients with ventricular arrhythmias

The clinical manifestations of ventricular arrhythmias encompass a broad spectrum, from complete absence of symptoms to sudden death. Although our understanding of the pathophysiology and natural history of these arrhythmias has advanced significantly over the past decade, large gaps in our knowledge remain, especially in patients with heart failure not due to coronary artery disease. We have learned much about the appropriate roles of antiarrhythmic drugs and implantable defibrillators in the prevention of sudden death. Studies performed over the past decade have made clear that the primary treatment for patients at high risk for life-threatening ventricular arrhythmias should be the implantable defibrillator. However, specific syndromes causing ventricular tachyarrhythmias are being recognized, and care must be individualized. Although hospital mortality from acute myocardial infarction has decreased as a result of newer therapies, sudden death after hospital discharge remains an important problem, causing at least 30% of post-infarction deaths, even in patients who have received thrombolytic therapy. Two independent studies have confirmed that patients with asymptomatic non-sustained ventricular tachycardia in the presence of left ventricular ejection fraction < .40 after myocardial infarction who have sustained ventricular tachycardia inducible by electrophysiologic study are at significant risk for sudden death. This risk is significantly reduced by ICD, but not pharmacologic, antiarrhythmic therapy. Our major challenge at this time is not how best to treat high risk patients, but how best to identify them prior to events. Finally, physicians should be aware that many symptomatic ventricular tachycardias are now curable at low risk, using catheters to deliver radiofrequency energy.