abnormal impulse conducting system conduction abnormal heart electrocardiography waveform feature any anomaly in the pattern of the graphic record of the integrated action currents of the cardiac cycle represented as changes in voltage; the prominent waves in the ECG correspond to specific conduction activity in areas of the heart and the timing and amplitude of ECG waveforms provide valuable information about heart rate and rhythm abnormal EKG MP:0010508 abnormal heart ECG waveform features MPheno.ontology abnormal cardiac electrocardiography 2010-09-30T04:16:30Z csmith abnormal ECG