Portable electrocardiographic monitoring: performance in patients with short P-R intervals without delta waves.

Twenty-four-hour continuous protable tape-recorded electrocardiograms were obtained in 24 patients with short P-R intervals without delta waves. Atrial premature beats were noted in 15 patients (62%), paroxysmal supraventricular tachycardia (PSVT) in 5 (21%), ventricular premature beats in 14 (58%), and noticeable ventricular arrhythmia in 5 (21%). All episodes of PSVT reflected either unifocal or multifocal atrial ectopic firing. Atrioventricular nodal reentrant PSVT was not observed. Electrocardiographic correlation of symptoms with arrhythmias was not striking. In 21 of the patients, the P-R interval remained short constant through the 24-hour recording period. Patients with a short P-R interval without delta waves have frequent arrhythmias involving multiple areas of the conduction system. The presence of an accessory atrioventricular connection (James tract) would not explain the arrhythmias recorded in these patients.