Author + information
- Received February 15, 1983
- Accepted April 8, 1983
- Published online September 1, 1983.
- Alan K. Woelfel, MD,
- Ross J. Simpson Jr., MD, FACC,
- Leonard S. Gettes, MD, FACC and
- James R. Foster, MD, FACC*
- ↵*Address for reprints: James R. Foster, MD. 349 Clinical Sciences Bldg. 229H, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27514.
Three patients with 1:1 atrioventricular (AV) conduction at rest developed fixed 2:1 or 3:1 AV block during treadmill exercise testing. Electrophysiologic study documented block distal to the AV node in all three patients, and suggested that the exercise-induced block occurred because of increased atrial rate and abnormal refractoriness of the His-Purkinje conduction system.
The findings in these three patients suggest that high grade AV block appearing during exercise reflects conduction disease of the His-Purkinje system rather than of the AV node, even in the absence of bundle branch block. Patients with this diagnosis should be considered for permanent cardiac pacing.
This study was supported in part by Training Grants HL 27430, HL 26484-02 and HL 07470 from the National Institutes of Health, Bethesda, Maryland.
- Received February 15, 1983.
- Accepted April 8, 1983.
- American College of Cardiology Foundation