Objective: The role of ambulatory acoustic cardiography in the management of patients with acute heart failure syndrome (AHFS) remains uncertain. We investigated the usefulness of the ambulatory acoustic cardiography in the prediction of cardiac mortality and re-hospitalization for patients with AHFS. Methods:A total of 75 patients (72.5?14.3 years old, 63 men) hospitalized for AHFS were enrolled and followed up for up to 24 months after discharge. All patients would undergo echocardiographic study, evaluations of arterial stiffness, and ambulatory acoustic cardiographyic monitoring before discharge. Circadian variations of electromechanical activation time (EMAT) were obtained.Results: During a mean follow-up of 387?280 days, 38 patients (50.6%) experienced events including re-hospitalization for heart failure or mortality. After accounting for age and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, 24h-EMAT significantly predicted post-discharge events [hazard ratioper 1-SD and 95% confidence intervals: 1.021(1.004-1.039)]. Diurnal variation of EMAT more prevailed in patients with events than those without events. Increase in nocturnal EMAT (non-dipping pattern) predicted events independent of age, NT-proBNP levels, and 24h-EMAT.Conclusion: Ambulatory acoustic cardiography could be a useful technology to evaluate the risks of patients with AHFS. Nocturnal non-dipping EMAT is an independent predictor for post-discharge adverse events and warrant optimal treatment.