Sensitivity and accuracy in recording His-Purkinje activity by surface-averaged electrocardiography

A clinical evaluation of the surface-averaged ECG (SAE) to record His-Purkinje activity (HPA) was made on 70 patients who underwent His bundle electrograms (HBE). The recorded signals first judged as HPA in 43 patients by the noninvasive method alone were later verified in 37 patients by HBE; the accuracy of the HPA recordings (predictive value) was 86.0%. The HPA-V interval measured noninvasively had a high correlation with the HV interval by HBE (r = 0.89, p less than 0.01). The verified detection rate in all 70 patients was 52.9%: HPA was detected in 12 of 18 patients (66.7%) with sclerotic and hypertensive heart disease (Group I), five of 19 patients (26.3%) with rheumatic heart disease (Group II), 11 of 17 patients (64.7%) with congenital heart disease (Group III), and nine of 16 patients (56.2%) with miscellaneous conditions (Group IV). The detection rate was markedly lower in Group II than in other groups (Group II vs Group I or III, p less than 0.025). The PR segment was significantly longer in the patients in whom HPA was detected than in those in whom it was not detected (71.5 +/- 22.3 msec vs 43.9 +/- 19.5 msec, p less than 0.001). His-Purkinje activity (HPA) was detected in 32 of 52 recordings (61.5%) with sinus rhythm and seven of 20 recordings (35.0%) with atrial fibrillation, including two recordings in each of two cardioverted patients (p less than 0.05). We conclude that the surface-averaged ECG (SAE) has clinically acceptable sensitivity and accuracy except in patients with rheumatic heart disease, short PR segments or atrial fibrillations.