Author + information
- Received October 9, 1984
- Revision received December 26, 1984
- Accepted January 9, 1985
- Published online July 1, 1985.
- Nabil El-Sherif, MD, FACCa,
- William B. Gough, PhD,
- Robert H. Zeiler, PhD and
- Robert Hariman, MD, FACC
- ↵aAddress for reprints: Nabil El-Sherif, MD, Cardiology Division, State University of New York, Downstate Medical Center, Box 1199, 450 Clarkson Avenue, Brooklyn, New York 11203.
One to 5 days after one-stage ligation of the left anterior descending coronary artery in dogs, reentrant excitation can be induced by programmed premature stimulation in the surviving electrophysiologically abnormal, thin epicardial layer overlying the infarct. In experiments in four dogs, reentrant excitation occurred “spontaneously” during a regular sinus or atria) rhythm. A tachycardia-dependent Wenckebach conduction sequence in a potentially reentrant pathway was the initiating mechanism for spontaneous reentrant tachycardias and was the basis for both manifest and concealed reentrant extrasystolic rhythms. In all dogs showing spontaneous reentry, reentrant excitation could also be induced by premature stimulation at cycle lengths much shorter than those associated with spontaneous reentry, and induced reentrant circuits were always different from those during spontaneous reentry. In two dogs, the reentrant circuit was located intramurally in close proximity to a patchy septal infarction.
The study illustrates that irrespective of the anatomic localization of reentrant circuits (epicardial or intramural), their dimension (large or small) or their mechanism of initiation (programmed premature stimulation or “spontaneous”), reentrant excitation always occurred in a figure 8 configuration (or a modification thereof). The figure 8 model, rather than the ring model or the leading circle model, may be the common model of reentry in the mammalian heart.
This study was supported by Veterans Administration Medical Research Funds, Washington, D.C.
- Received October 9, 1984.
- Revision received December 26, 1984.
- Accepted January 9, 1985.
- American College of Cardiology Foundation