PURPOSE: QRS complex width is not an accurate marker of left ventricular mechanical dyssynchrony (LVMD). Echocardiography is the optimal tool to assess LVMD, but results are inconsistent. LVMD determined by a method using combined pulsed wave Doppler (PW) and tissue Doppler imaging (TDI) is a novel method and has been recently reported. Our aims were to evaluate the sensitivity, specificity, positive and negative predictive value and agreement with positive response of cardiac resynchronization therapy (CRT) by using this method.
METHODS: We studied 108 consecutive patients [male 78, female 30, age 69.9± 9.7 years] with CRT [left ventricular ejection fraction (LVEF) ≤; 35% (20.4±6.7 %) and NYHA class III-IV and QRS duration ≥ 120ms (165.2±28.3 ms)]. Patients with atrial fibrillation were excluded. There were 69 patients with ischemic cardiomyopathy and 39 patients with non-ischemic cardiomyopathy. The difference (PW-TDI) between the time from onset of QRS to the LV ejection end by PW and the time from onset of QRS to the end of the systolic wave in basal segment with greatest delay by TDI was measured before CRT. PW-TDI > 50ms was defined as LVMD. Left ventricular volume at end systole decreasing ≥15% after CRT was defined as a positive response to CRT.
RESULTS: PW-TDI interval before CRT was 73.9±47.8 ms. During follow-up of 15± 10.9 months, the sensitivity, specificity, positive and negative predictive values in LVMD determined by PW-TDI to CRT responders were 98%, 82%, 81% and 98%, respectively. Area under the ROC curve was 0.92 (Fig1). There was a great agreement between LVMD determined by PW-TDI and the positive response to CRT (Kappa= 0.80).
CONCLUSION: Left ventricular dyssynchrony detected by the method combining pulsed wave Doppler and tissue Doppler demonstrated a high sensitivity, specificity, positive and negative predictive values and agreement with positive response to CRT.
CLINICAL IMPLICATIONS: This study provided a new and reliable method to detect LVMD.
DISCLOSURE: Kishlay Anand, None.