Shock Reduction Programming and Heart Function Recovery in Japanese Patients Undergoing Implantable Cardioverter Defibrillator Implantation for Primary Prevention　― A Single-Center Prospective Study ―

Abstract

Background: Although implantable cardioverter-defibrillators (ICD) offer prognostic benefit for patients with reduced left ventricular ejection fraction (LVEF), they remain underused in Japan.

Methods and Results: We analyzed 25 patients who underwent primary prevention ICD implantation. During a median follow-up of 52.6 months, no appropriate shocks occurred, but non-sustained ventricular tachycardia (NSVT) was frequently observed. Two patients underwent antitachycardia pacing. LVEF improved to >35% in nearly half of the patients.

Conclusions: Cardiac resynchronization therapy and pharmacotherapy possibly improved cardiac function. Unnecessary shock delivery programming may have also contributed to the favorable outcomes.