Sudden Death in Patients With Cardiac Implantable Electronic Devices

Abstract

Interrogations and autopsies of sudden deaths with cardiac implantable electronic devices (CIEDs) are rarely performed. Therefore, causes of sudden deaths with these devices and the incidence of device failure are unknown.OBJECTIVE To determine causes of death in individuals with CIEDs in a prospective autopsy study of all sudden deaths over 35 months as part of the San Francisco, California, Postmortem Systematic Investigation of Sudden Cardiac Death (POST SCD) study. DESIGN, SETTING, AND PARTICIPANTS Full autopsy, toxicology, histology, and device interrogation were performed on incident sudden cardiac deaths with pacemakers or implantable cardioverter defibrillators (ICDs). The setting was the Office of the Chief Medical Examiner, City and County of San Francisco. Participants included all sudden deaths captured through active surveillance of all deaths reported to the medical examiner and San Francisco residents with an ICD (January 1, 2011, to November 30, 2013). MAIN OUTCOMES AND MEASURESIdentification of a device concern in sudden deaths with CIEDs, including hardware failures, device algorithm issues, device programming issues, and improper device selection. For the ICD population, outcomes were the cumulative incidence of death and sudden cardiac death and the proportion of deaths with an ICD concern.RESULTS Twenty-two of 517 sudden deaths (4.3%) had CIEDs, and autopsy revealed a noncardiac cause of death in 6. Six of 14 pacemaker sudden deaths and 7 of 8 ICD sudden deaths died of ventricular tachycardia or ventricular fibrillation. Device concerns were identified in half (4 pacemakers and 7 ICDs), including 3 hardware failures contributing directly to death (1 rapid battery depletion with a sudden drop in pacing output and 2 lead fractures), 5 ICDs with ventricular fibrillation undersensing, 1 ICD with ventricular tachycardia missed due to programming, 1 improper device selection, and a pacemaker-dependent patient with pneumonia and concern about lead fracture. Of 712 San Francisco residents with an ICD during the study period, 109 died (15.3% cumulative 35-month incidence of death), and the 7 ICD concerns represent 6.4% of all ICD deaths. CONCLUSIONS AND RELEVANCE Systematic interrogation and autopsy of sudden deaths in one city identified concerns about CIED function that might otherwise not have been observed. Current passive surveillance efforts may underestimate device malfunction. These methods can provide unbiased data regarding causes of sudden death in individuals with CIEDs and improve surveillance for CIED problems.

Sudden Cardiac Death Despite a Functional Cardioverter‐Defibrillator: The Case for Early and Aggressive Therapy for Ventricular Tachycardia in Selected Patients

“…It is also useful to evaluate these patients in the context of the overall population experiencing sudden death with cardiac implantable defibrillators, recently reported in a prospective autopsy study published by Tseng et al 12 One patient in that series had ventricular tachycardia "missed due to programming," the description that would best fit the patients presented here. That frequency in the ICD population of a major metropolitan area over a 35-month period suggests that this is an exceptionally rare occurrence.…”

Failure to detect life‐threatening arrhythmias in ICDs using single‐chamber detection criteria

“…In an autopsy study, Tseng et al. described six patients with sudden death despite a functional ICD . Undersensing of VF occurred in five patients; in one patient the VT was slower than the programmed detection rate.…”

“…A matter of concern is the anecdotal reports of sudden cardiac death despite a functional defibrillator . In this report, we describe another 24 patients with a fatal or near‐fatal arrhythmic event due to failure to detect ongoing life‐threatening ventricular tachyarrhythmias (VAs).…”

“…The hatched area contains a 4-second period of uninterrupted charging during ongoing PVT. Abbreviations: -= unbinned interval; * = charging for shock delivery; Ars = atrial refractory sense, i.e., atrial event detected in the atrial refractory period; F = binned interval in VF zone; FF = far-field; ID = initial detection; mon = monitoring zone; PVT = polymorphic VT; VF = ventricular fibrillation; VS = ventricular sensed event; VT = ventricular tachycardia; VT2 = VT2 zone; sinus = sinus zone [Color figure can be viewed at wileyonlinelibrary.com] study, Tseng et al described six patients with sudden death despite a functional ICD 7. Undersensing of VF occurred in five patients; in one patient the VT was slower than the programmed detection rate.Montgomery et al reported on three cases of sudden death dueto sustained VT that fell below the programmed detection rate 8.…”

Athletes with implantable cardioverter defibrillators: can they return to competitive sports?

“…One patient had a known moricizine-induced rise in defibrillation threshold9 and a second case had alcohol intoxication 10. ICDs are not 100% effective in preventing deaths from ventricular arrhythmias,11 and it does not seem that this small number of failed shocks is greater than otherwise would be expected in ICD recipients.…”