A Retrospective Analysis Of Inappropriate Implantable Cardioverter-Defibrillator Therapies In High-Risk Sudden Cardiac Death Patients

ObjectivesThe purpose of this retrospective, single-center study was to identify the incidence, common causes, predictors, and clinical outcomes of inappropriate therapies in implantable cardioverter-defibrillator (ICD) patients, and also, to seek the management options to reduce inappropriate therapies.MethodsTotally 123 patients implanted with ICD for the first time in Peking Union Medical College Hospital from January 2006 to December 2014 were involved in our study. The patients were followed up 3 months after implantation and every year after that. Three experienced electrophysiologists would review and reevaluate the appropriateness of ICD therapies according to the intracardiac electrocardiogram recordings. Any ICD therapy not delivered for ventricular tachycardia (VT) or ventricular fibrillation (VF) was deemed to be inappropriate therapy.ResultsDuring the median follow-up period of 36 months, One or more inappropriate therapies occurred in 28 (22.8%) of the 123 patients. Inappropriate therapy episodes constituted 161 (55.1%) of the 292 total therapy episodes. Among the 118 inappropriate therapy episodes in VT/FVT detection zone,90 (76.3%) received only anti-tachycardia pacing (ATP), and most inappropriate shocks (96%) were delivered after 1-2 ATP attempts. Atrial fibrillation/flutter was the most common cause of inappropriate therapies (63.3%). A history of atrial fibrillation/flutter, single-chamber ICD, absence of hypertension and absence of diabetes were the independent predictors of inappropriate therapy. There was a significant increase of inappropriate therapy occurrence in single-chamber ICD comparing with dual-chamber ICD or CRT-D (p<0.001). No significant difference was observed in the incidence of inappropriate therapy when comparing primary and secondary prevention groups (p=0.433).ConclusionInappropriate therapies occurred commonly in our study and the most common cause is atrial fibrillation/flutter. A history of atrial fibrillation/flutter, single-chamber ICD, absence of hypertension and absence of diabetes were associated with increased risk of inappropriate therapy. Programming a higher number of ATP attempts could reduce inappropriate shocks in ICD recipients.