Late potentials bridging diastole

Shown are surface ECG leads I, II, III, V1, V4, and V6 and electrograms (a to h) recorded from the endocardial surface of the myocardium during ventricular tachycardia. There are presystolic signals in the area of slow myocardial conduction that can be traced through diastole to the preceding QRS complex. During sinus rhythm, late potentials can be recorded from these sites.