Electrical and mechanical predictors in response to cardiac resynchronisation therapy

Abstract

Results: Responders were 27 (20M-7F; 60%) and CRT improved IMVD (p 400 msc and Q-S delay >65 msc between two basal segments selected the patient who will benefit of CRT. Background and purpose: Cardiac resynchronization therapy (CRT) was shown to reverse left ventricular (LV) remodeling in patients with congestive heart failure (CHF). The prediction of LV function im- provement was demonstrated for intraventricular and interventricular asynchrony degree, evaluated by tissue Doppler imaging echocardiog- raphy. The aim of the study was to investigate whether intraoperative electrocardiographic (ECG) and electrophysiological (EP) parameters were also predictive factors of LV reverse remodeling after CRT. Methods and results: Forty-nine patients with CHF were implanted with resynchronization devices. During procedure, several ECG and EP parameters were evaluated without pacing, with fight ventricular pacing (RVp), LV pacing (LVp) and biventricular pacing (Bp). At follow-up (mean 9 months) responders (n=27) were defined by a relative increase in LV ejection fraction more or equal than 25% compared with baseline. Several ECG and EP parameters, evaluating electrical asynchrony during LVp or RVp, were shown to predict LV reverse remodeling. Receiver operating curve analysis revealed the ratio of QRS width during BP and RVp (Bp/RVp index) as the best predictor of LV functional recovery after resynchronization (area under the curve=0.82). The value of the Bp/RVp index with the best predictive accuracy resulted 0.78. The Bp/RVp index correlated significantly with the improvement of LV ejection fraction (r= -0.49, p<0.005) at follow-up and with LV free wall activation time relative to QRS (r= -0.52, p<0.005). Clinical and