ArticleNasrallah AT, Gillette PC, Mullins CE, Nihill MR, McNamara DG.
Am J Cardiol. 1975 Feb;35(2):288-92.
His bundle electrograms were recorded in two children with cardiac conduction disturbances. In the surface electrocardiograms of one patient His bundle extrasystoles mimicked atrial nonconducted bigeminal rhythms; in the other, they simulated second degree atrioventricular (A-V) block and conducted junctional extrasystoles. In both instances the conduction disturbance was a result of concealed conduction of the His bundle extrasystole into the A-V junction. We conclude that the surface electrocardiogram is suggestive but not definitive in diagnosing His bundle extrasystoles and that His bundle recordings are indispensable for correct diagnosis and treatment.