Pathophysiological insights into abnormal intra-QRS signals in the high resolution ECG

Presents the idea of abnormal intra-QRS potentials, analogous to conventional late potentials, in the experimental setting of canine myocardial infarction. The link between delayed or slow conduction-evidenced by late potentials-and a reentry mechanism for ventricular tachycardia has been well established. However, the question of whether abnormal intra-QRS potentials may be arrhythmogenic has not been addressed. It is hypothesized that these potentials may reflect disruption and/or delay in ventricular conduction that is potentially arrhythmogenic. If verified, the concept of late potentials might be usefully expanded to include abnormal potentials occurring anywhere within the period of the high resolution QRS complex, as opposed to only the terminal portion.