A changing scenario in the clinical use of implantable defibrillators: the need for long-term data on lead performance.

The story of electrical therapies for the heart began 50 years ago, with the pioneering experience of Senning and Elmqvist, who implanted the first pacemaker at Karolinska hospital in Stockholm on 8 October 1958.1 Since then electrical therapies have undergone an impressive technological evolution with important implications on the clinical use of electrical devices and the outcome of implanted patients. Two clinical steps in the evolution of electrical therapies were the conception and the clinical validation of implantable cardioverter defibrillators (ICDs) and devices for cardiac resynchronization therapy, which have extended the benefit of treatment with electrical devices to a much wider proportion of patients affected by heart diseases.1,2 The treatment with ICDs was conceived more than 30 years ago as a last-resort intervention for highly selected patients who had survived at least two episodes of cardiac arrest.2 In the first years after its approval by the FDA in 1985, the overall number of ICD implantations thus remained low, both in the US and Europe.2 In the last decade, the scenario of clinical use of ICDs changed dramatically and randomized clinical trials have prompted a widening of clinical indications, with a shift towards increasing use of ICDs in the setting of primary prevention of sudden cardiac death, for patients identified as subjects at increased risk for life-threatening ventricular tachyarrhythmias.