We report a case of subcutaneous implantable cardioverter-defibrillator implantation in a morbidly obese pediatric patient with hypertrophic cardiomyopathy for the primary prevention of sudden cardiac death. During routine defibrillator threshold testing of the newly placed subcutaneous implantable cardioverter defibrillator, normal sinus rhythm could not be restored despite repeated attempts at defibrillation using the subcutaneous implantable cardioverter defibrillator and transcutaneous pads. Here, we describe the successful intraoperative resuscitation and management after failure to restore normal sinus rhythm using the newly placed subcutaneous implantable cardioverter defibrillator and repeated transcutaneous defibrillation attempts.