092: Prognosis value of QRS duration in patients with heart disease and syncope

Abstract

Patients with heart disease (HD) and syncope are at high risk of sudden death. Implantable defibrillator (ICD) is recommended in patients with unexplained syncope and left ventricular ejection fraction (LVEF) < 30% or in patients with LVEF >30% and inducible ventricular tachycardia (VT). The purpose of the study was to evaluate the prognostic significance of QRS duration measurement in patients with HD and syncope. 528 patients, 89 women and 439 men, mean age 65±12 years, were admitted for syncope. All of them had an HD, either ischemic HD (n=382) or left ventricular impairment of other origin (n=115). Holter monitoring, electrophysiological study and head-up tilt test were systematic. Filtered QRS duration was measured at signal-averaged ECG (Fidelity 2000 of Cardionics) (filter 40 Hz, noise level < 0.6 μV). The patients were followed from 3 months up to 18 years (mean 5 ±4 years). Mean LVEF was 40±14%. Cardiac defibrillator was implanted in 73 patients. 30 patients died suddenly, 75 died from heart failure or were transplanted (n=9). Remaining patients are alive or died from non cardiac death (n= 8). The last group differed from group who died suddenly by an higher LVEF (42±14% vs 32±13) (p< 0.00001) and a shorter QRS duration (125±34 msec vs 144±31) (p< 0.026). They tended to be older (65±12 years vs 61±13) (p<0.09). The alive group differed also from group who died from heart failure by an higher LVEF (42±14% vs 33±13) (p< 0.001) and a shorter QRS duration (125±34 msec vs 141±31) (p< 0.0033). They tended to be younger (65±12 years vs 67±10) (p<0.08). Patients who died suddenly and those who died from heart failure had similar LVEF and QRS duration but patients who died suddenly are younger than patients who died from heart failure (p<0.01). Low LVEF is a classical risk of worse prognosis in patients with HD and syncope. A longer QRS duration is also a noninvasive and simple test of worse prognosis. A QRS duration more than 125 msec had a sensitivity of 73% and a specificity of 64% to predict cardiac mortality.