A system provides an image acquisition trigger signal compensated for signal processing time delay. An interface receives waveform signal data representing electrical activity of a patient heart over at least one heart beat cycle. A detector detects a particular point associated with a particular signal portion within successive heart beat cycles of the signal data. A first time variation detector provides a first timing adjustment signal in response to detected change in time of occurrence of the detected particular point. A second time variation detector provides a second timing adjustment signal in response to comparison of relative timing of the trigger signal and the detected particular point. An output processor generates the trigger signal in response to the detected particular point and the first timing adjustment signal and the second timing adjustment signal.
