Sudden cardiac death syndrome and pump dysfunction: the link.

Clearly, sudden cardiac death syndrome in heart failure is linked to severely perturbed neurohumoral, hemodynamic, and mechanical systems. Routine antiarrhythmic drug therapy has not proven beneficial and, therefore, there is no justification for using these agents in unselected heart failure patients who are without significant symptomatic ventricular arrhythmia. Aggressive treatment of the failure syndrome seems most important. Because many of the problematic arrhythmias arise from triggering automaticity, which is known to occur in excessive ventricular stretch and wall stress, systemic vascular "unloading" with vasodilators and angiotensin-converting enzyme inhibitors is likely helpful. The most recent American College of Cardiology/American Heart Association Guidelines regarding therapeutic management of heart failure suggest that aggressive pharmacologic treatment of asymptomatic ventricular arrhythmias is best avoided. To be considered strongly for pharmacologic prescription or for implantation of a tachyarrhythmia termination device, a patient should have symptomatic ventricular tachycardia with an episode of syncope or sudden cardiac death syndrome rather than simply having palpitations of asymptomatic, unsustained ventricular tachycardia. Indeed, aggressively treating congestive heart failure with medication often eliminates potentially life-threatening arrhythmias. Appropriate use of vasodilators and, particularly, angiotensin-converting enzyme inhibitors is important. Correction of fluid balance and electrolyte disorders may be helpful to address symptoms and certainly is likely to decrease the potential for morbidity and mortality. On occasion it may be necessary to consider bradyarrhythmia pacemaker insertion or the use of atrioventricular nodal-ablation techniques with subsequent ventricular or atrioventricular pacer insertion. Obviously, sudden cardiac death due to sudden heart block or asystole might be attenuated with this strategy.