Mark Josephson dedicated his career to the prevention of premature sudden cardiac death (SCD). Toward that goal, he was an early adopter of the implantable cardioverter defibrillator (ICD) and indefatigable advocate for better ICD technology,[1] both as a clinical tool and as living laboratory to study SCD in ambulatory patients. With characteristic intellectual integrity and analytical rigour, he sought an honest and balanced appraisal of the life-saving benefits and serious complications of this unique therapy.