Crinkling of epicardial defibrillator patches. A common and serious problem

The durability and reliability of the implantable cardioverter-defibrillator epicardial patch systems have not been reported. In 128 consecutive patients such systems manufactured by Cardiac Pacemakers, Inc. (St. Paul, Minn.) or Medtronic, Inc. (Minneapolis, Minn.) were implanted with 100% follow-up to investigate the rate of patch crinkling and its consequences. A total of 122 patients survived the operation (operative mortality, 6 patients: 4.7%). Ninety-four patients received Cardiac Pacemakers, Inc. AICD patches and 28 received Medtronic PCD patches. Patients had chest x-ray studies every 3 to 6 months and function of the defibrillator was checked every 3 months. Late mortality occurred in 17 patients (13%) leaving a total of 105 long-term survivors (82%) to the present. Among 122 survivors, severe crinkling of the patches occurred in 48 patients--33 in the Cardiac Pacemakers, Inc. AICD group (36%) and 15 in the PCD group (54%)--within 2 years of the implant. Crinkling of patches caused not only malfunction of the system, but also cardiac pain in three patients. Crinkling occurred as early as 2 months after implant and progressed throughout the period of observation. Fourteen patients later required implant of an additional transvenous defibrillator because of failure of the epicardial system. The percentage of transvenous implantable cardioverter-defibrillator systems needed was higher for the Medtronic group (28%) than for the Cardiac Pacemakers, Inc. AICD group (6.3%). Both systems have shown an unacceptably high rate of patch crinkling that occurs in a relatively short time. There is no difference whether a thoracotomy or midline sternotomy is used or whether the patches are implanted intrapericardially or extrapericardially. The quest should continue for a better patch system design.