New indications for pacing.

This article reviews developments in four areas: single- versus dual-chamber pacing, pacing for prevention of atrial fibrillation (AF), pacing for the treatment of neuromediated syncope, and pacing in patients with congestive heart failure. Large, randomized clinical trials comparing physiologic and ventricular pacing in different pacemaker populations have demonstrated that physiologic pacing does prevent AF but does not reduce cardiac mortality or stroke. The benefit for prevention of AF appears to be in patients with sinus node disease as the primary indication for pacing. Selective atrial pacing algorithms designed for the prevention of AF have not been shown to substantially reduce the overall burden of AF. Cardiac pacing has been shown to have a moderate benefit in the treatment of neuromediated syncope. Cardiac resynchronization therapy is emerging as a promising new treatment for heart failure. Long-term studies report that it improves quality of life and functional capacity, and reduces hospitalizations for heart failure. The impact of this therapy on mortality awaits the results of ongoing studies.