Author + information
- Received August 4, 1986
- Revision received October 14, 1986
- Accepted November 3, 1986
- Published online May 1, 1987.
- Fred Morady, MD, FACC*,1,
- Lorenzo A. DiCarlo Jr., MD1,
- Ryszard B. Krol, MD1,
- Thomas M. Annesley, PhD1,
- William W. O’neill, MD1,
- Michael de Buitleir, MB1,
- Jeffrey M. Baerman, MD1 and
- William H. Kou, MD1
- ↵*Address for reprints: Fred Morady, MD, Division of Cardiology, University of Michigan Hospitals, 1500 East Medical Center Drive, UH Bl F245-0022, Ann Arbor, Michigan 48109-0022.
The role of ischemia in the induction of ventricular tachycardia during programmed stimulation was studied in 19 patients who survived a cardiac arrest and were found to have a significant stenosis in at least one branch of the left coronary artery. The arterial-coronary sinus lactate difference was measured during electrophysiologic testing, before the induction of ventricular tachycardia. Ventricular tachycardia was induced in 15 patients; it was sustained and unimorphic in 6 patients and polymorphic in 9. Myocardial ischemia, as reflected by net myocardial lactate production, was present within 60 seconds before the induction of ventricular tachycardia in 8 of the 15 patients with inducible ventricular tachycardia.
In 9 of the 15 patients, programmed stimulation was repeated after a 15 minute rest period, with the same coupling intervals that had induced ventricular tachycardia previously. Net myocardial lactate production was not present in any patient during this repeat attempt. In three patients without evidence of ischemia during the first induction of ventricular tachycardia, the arrhythmia was induced again by the specific coupling intervals that had induced it previously. However, in five of six patients with net myocardial lactate production during the first induction of ventricular tachycardia, the same coupling intervals that had induced the arrhythmia in the presence of ischemia no longer induced it in the absence of ischemia.
The results of this study suggest that myocardial ischemia may be a requirement for the induction of ventricular tachycardia in some patients with coronary artery disease who survive a cardiac arrest.
- Received August 4, 1986.
- Revision received October 14, 1986.
- Accepted November 3, 1986.
- American College of Cardiology Foundation