A computer method, employable during an at-rest period of a pacemaker patient, for controlling the operation of the pacemaker so as maximally to support the patient's hemodynamic behavior in a context involving inhibiting fluid overload. The method involves (a) collecting simultaneously occurring ECG and heart-sound information, (b) processing the collected information to obtain at least S3 data, and in certain instances also EMAT and/or % LVST data, (c) utilizing such obtained data, and during the at-rest period, applying (a) pacing rate, (b) pacing intensity, (c) atrio-ventricular delay, and (d) inter-ventricular delay control to the pacemaker. Processing involves (a) calculating from the obtained data an actual, real-time, acoustic cardiographic therapy (AC) value which is to be employed in relation to controlling pacemaker activity, and (b) comparing the actual AC value to a pre-established, related, rest-period-associated, reference AC value to detect differences therebetween, with the utilizing and applying steps being implemented so as to minimize such differences.