Subcutaneous Implantable Cardioverter-Defibrillator Shocks After Left Ventricular Assist Device Implantation.

Abstract

A 42-year-old man experiencing nonischemic cardiomyopathy with severely reduced left ventricular function and advanced heart failure met the criteria for primary prophylactic implantation of an implantable cardioverter-defibrillator (ICD). A subcutaneous ICD (S-ICD; EMBLEM; Boston Scientific, Marlborough, MA) was implanted at a secondary center in November 2015 with the lead (3401; Boston Scientific) tunnelled in left parasternal position. Before implantation, surface ECG screening was performed following the manufacturer’s instructions. A few weeks later, the patient was transferred to Hannover Medical School because of heart failure deterioration (New York Heart Association class IV). After careful evaluation, a continuous-flow left ventricular assist device (LVAD; HeartMate 3; Thoratec, Pleasanton, CA) was implanted using conventional sternotomy.1 Approximately 1 hour after LVAD implantation, the patient received 31 S-ICD shocks. The device was immediately deactivated. Interrogation of the S-ICD revealed normal sinus rhythm during the shocks. However, R waves were diminished and superimposed by electric …