A three dimensional ultrasonic imaging system acquires volume segments of a wide field of view volume image in coincidence with an ECG waveform. The ECG waveforms acquired during acquisition of the volume segments are displayed in a comparative display in which a different ECG waveform can be visually distinguished. A volume segment acquired during an arrhythmic heartbeat can be reacquired or replaced in the wide field of view volume data set. The ECG waveforms can be displayed vertically aligned by their R-waves, in overlapping alignment, or differently shaded or colored. A processor can compare the ECG waveforms automatically and automatically replace the data of a volume segment acquired during an arrhythmic heartbeat.