Double ventricular response to an extrastimulus in a patient with triple atrioventricular pathways

• Published in: Chest Vol. 74; no. 5; p. 593
• Main Authors: Pimenta, J, Miranda, M, Silva, L A
• Format: Journal Article
• Language: English
• Published: United States 01.11.1978
• Subjects: Bundle of His - physiopathology; Electrocardiography; Heart Conduction System - physiopathology; Heart Ventricles - physiopathology; Humans; Male; Middle Aged; Wolff-Parkinson-White Syndrome - physiopathology
• ISSN: 0012-3692
• DOI: 10.1378/chest.74.5.593

A patient with the Wolff-Parkinson-White Syndrome was studied through recordings of the intracardiac potentials and programmed atrial stimulation. During programmed atrial stimulation at progressively shorter coupling intervals (A1-A2 intervals), the His deflection was always recorded after the ventricular complex. Thus, at coupling intervals between 295 and 250 msec, there was a double ventricular response, one through the accessory pathway (QRS complex of the Wolff-Parkinson-White morphologic pattern) and the other by the normal atrioventricular pathway (normal QRS complex or with pattern of left bundle-branch block). At a coupling interval of 295 msec, the atrio-His (A-H) interval increased from 200 to 350 msec. This fact and the presence of two distinct A2-H2 intervals are suggestive of the existence of dual atrioventricular pathways, coexisting functionally with a lateral accessory bypass (Kent's bundle).