The rate-corrected QT interval calculated from 24-hour Holter recordings may serve as a significant arrhythmia risk stratifier in heart failure patients.

摘要

To examine the ability of repolarization markers: QT, QTc, QTa/RR, QTe/RR to serve as predictors of life-threatening arrhythmias in heart failure (HF) patients [1], we screened non-invasively a cohort of 221 patients presenting with left ventricular ejection fraction (LVEF) < 50%. All patients gave informed consent and the study was approved by our institution's Ethics Committee. All patients underwent 12 lead ECG, ECHO, Signal Averaged ECG (SAECG) and 24-h Holter (HM). Patients with nonsustained ventricular tachycardia (NSVT) were further risk stratified by EPS. The patients with clinical or inducible on EPS ventricular tachycardia and/or ventricular fibrillation (VT/VF) received an ICD. The study population was divided in the high risk group including 62 patients (20 with history of clinical VT/VF and 42 with inducible VT/VF on EPS) and in the low risk group including the rest 159 arrhythmia-free patients. Each participant underwent a 12-lead ECG at 25 mm/s (MAC 5000, GE Marquette Medical, Milwaukee, USA). The following intervals were measured in lead II: RR , QRS, QT and QTc (correction with Bazett's formula: QTc = QT/VRR.) A SAECG (MAC 5000 GE Medical, Milwaukee, USA) was performed.