QRS Prolongation is Associated With High Defibrillation Thresholds During Cardioverter-Defibrillator Implantations in Patients With Hypertrophic Cardiomyopathy

Takayuki Nagai, Takashi Kurita, Kazuhiro Satomi, Takashi Noda, Hideo Okamura, Wataru Shimizu, Kazuhiro Suyama, Naohiko Aihara, Junjiro Kobayashi, Shiro Kamakura
2009 Circulation Journal  
Although high defibrillation threshold (DFT) is a major and unavoidable clinical problem after implantation of an implantable cardioverter defibrillator (ICD), little is known about the cause and management of a high DFT in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to assess the predictors of a high DFT in patients with HCM. Methods and Results: Twenty-three patients with non-dilated HCM who underwent ICD implantation were included. The DFT at the time of
more » ... device implantation was measured in all patients. The patients were divided into 2 groups, a high DFT group (DFT ≥15J, n=13) and a low DFT group (DFT <15J, n=10); and their baseline characteristics were compared. The QRS duration was longer in the high than in the low DFT group (128±31 vs 103±12 ms, respectively; P=0.02). QRS duration, left ventricular (LV) end-systolic diameter, and LV ejection fraction were significant predictors of DFT in univariate analysis. However, in multivariate analysis, the only factor significantly associated with DFT was QRS duration (P=0.002). Conclusions: QRS duration is the most consistent predictor of a high DFT in HCM patients undergoing ICD implantation. (Circ J 2009; 73: 1028 -1032
doi:10.1253/circj.cj-08-0744 pmid:19359812 fatcat:goatbg2pzradzeigse2g2dp25y