BACKGROUND AND OBJECTIVES: The recovery of the left ventricular ejection fraction (LVEF) appeared to be prognostic of survival in congestive heart failure (CHF). The aim of our study was to evaluate the parameters that appear to predict the LVEF recovery in CHF. SUBJECTS AND METHODS: Forty-nine patients, with CHF and a LVEF< 35%, were enrolled. Doppler myocardial imaging was performed on 5-basal and 5-mid segments in order to assess the systolic duration, the time from the R-wave to the peak systolic velocity (RS time) and the time from the R-wave to the peak early diastolic velocity (RE time). The standard deviation (SD) of the RS time was an indicator of the 'systolic synchronicity'. After at least 3 months of full medical therapy, a follow-up echocardiography was performed. According to the changes in the LVEF, the patients were divided into groups I (< 5%, n=29) and II (> or =5%, n=20). RESULTS: The baseline clinical and echocardiographic parameters were similar in both groups. In group II, the LV end-systolic and end-diastolic volumes were decreased, but the LVEF was increased by up to 44% at the follow-up. The right ventricular annulus velocity (group I: 6.7+/-2.1 vs. group II: 8.0+/-2.0 cm/sec, p< 0.05), the use of beta-blocker (69 vs. 100%, p< 0.05) and the SD of the RS time (46+/-21 vs. 21+/-12, p< 0.01) were significantly different between the two groups. However, the systolic duration and the SD of the RE time were similar in the two groups. From a multivariate analysis, only the SD of the RS time was an independent predictor of the LVEF recovery. CONCLUSION: Myocardial systolic synchronicity is an important predictor of the LVEF recovery.