OBJECTIVES: The aim of this study was to determine whether QRS duration(QRSd) correlates with occurrence of ventricular arrhythmia in patients with coronary disease(CAD) receiving implantable cardioverter-defibrillators(ICDs). OBJECTIVES: A QRSd measured on a standard electrocardiograph(ECG) correlates with total mortality risk in CAD patients at high risk for sudden death; however, the relationship between QRSd and risk of ventricular tachyarrhythmias(ventricular tachycardia/ ventricular fibrillation[VT/VF]) is unclear. METHODS: PainFREE Rx II was a randomized trial, comparing efficacy of antitachycardia pacing versus shock therapy for VT/VF in patients receiving ICDs. We retrospectively correlated the QRSd and specific ECG conduction abnormalities on the 12-lead ECG at study entry with occurrence of VT/VF in 431 patients with CAD enrolled in the trial. RESULTS: The QRSd was ≤120 ms in 291 of 431(68%) patients. Left bundle branch block(LBBB) was present in 65 patients, right bundle branch block(RBBB) in 48 patients, and nonspecific intraventricular conduction delay(IVCD) was present in 124 patients. Over 12 months’follow-up, VT/VF occurred in 95(22%) patients(22%of patients with QRSd ≤120 ms vs. 23%of patients with QRSd >120 ms, p=NS). Patients with LBBB were less likely to experience at least one VT/VF episode than patients with QRSd< 120 ms. Patients with RBBB and nonspecific IVCD did not differ from patients with narrow QRS complexes with regard to occurrence of tachycardias. CONCLUSIONS: The QRSd and ECG conduction abnormalities are not useful to predict ICD benefit in patients having the characteristics of our study population. The utility of QRSd to predict VT/VF events in patients with CAD requires further prospective evaluation.
展开▼
