[Noninvasive recording of His-Purkinje activity in man].

To clarify the etiology of the prepotentials (PPs) between the end of P wave and the onset of QRS complex (P'-R segment) in signal averaged electrocardiogram (SAECG), SAECG was recorded in 26 healthy volunteers and 15 patients with idiopathic left ventricular tachycardia (VT) and electrophysiologic study (EPS) was done in those 15 VT patients. The PPs which had three components (PP1, PP2, PP3) were recorded in 14 of the 26 volunteers (53.8%) and 10 of the 15 VT patients (66.7%). The intervals from the PPs to the onset of QRS complex were 45.4 +/- 6.6, 30.6 +/- 5.6, 16.0 +/- 4.7 ms, respectively. These intervals in SAECG were very similar to the intervals from the electrograms of His bundle, right bundle, Purkinje network to the onset of QRS complex in EPS. The PPs in SAECG were thought to represent the electrical activity of His bundle, right bundle and Purkinje network.