Author + information
- Received June 7, 1983
- Revision received September 13, 1983
- Accepted September 19, 1983
- Published online March 1, 1984.
- Elias Botvinick, MD, FACCa,b,
- Michael Frais, MDc,
- William O'connell, MA,
- Donald Faulkner, CNMT,
- Melvin Scheinman, MD, FACC,
- Fred Morady, MD, FACC,
- Ruey Sung, MD, FACC,
- Dale Shosa, PhD and
- Michael Dae, MD
- ↵aAddress for reprints: Dr. Elias Botvinick, c/o Division of Cardiology, 1186-Moffitt Hospital, University of California, San Francisco, San Francisco, California 94143.
To localize bypass pathways, left and right ventricular regions were analyzed at rest by phase image analysis in 18 patients with ventricular pre-excitation syndromes. These were compared with image findings in 18 normal subjects. In each of 17 patients with pre-excitation, the site localized on electrophysiologic study correlated closely with the region of earliest ventricular phase angle. This site could be objectively separated from that in normal subjects in each of eight patients with an active left-sided pathway and in both patients with a right-sided pathway. Those with a septal pathway revealed earliest septal phase angle, but could not be separated from normal subjects. In the eight patients with an active left bypass tract, the onset, upstroke and peak of the left ventricular phase histogram preceded those of the right ventricular histogram. Those with a left-sided pathway demonstrated a mean left ventricular phase angle, a difference between mean left and mean right ventricular phase angle and a difference between earliest left and right ventricular phase angles which was significantly less than that in normal subjects (p < 0.05). These variables presented characteristic converse changes in those with a right-sided pathway.
Sequential phase changes in 10 studies suggested “fusion” of normal septal with lateral bypass fronts. Electrocardiographic and electrophysiologic localization of the bypass pathway agreed in only 8 of 14 patients with a recognized delta wave.
The phase image represents a new, noninvasive method of evaluating ventricular pre-excitation. The method may provide useful information complementary to that of electrocardiographic and electrophysiologic analysis.
↵b Dr. Botvinick is a recipient of an Established Investigator Award of the American Heart Association, Dallas, Texas, with funds contributed by the California Heart Association, San Francisco. He is also supported in part by a grant from the George D. Smith Foundation, San Francisco, California.
↵c Dr. Frais participated in this work while a Research Fellow in Cardiology and Nuclear Medicine at the University of California, San Francisco. He is now a Cardiology Fellow at the University of Calgary Hospitals, Calgary, Alberta, Canada.
This work is supported in part by grants from the California Heart Association, San Mateo, California, and from the Fanny Ripple Fund, Morristown, New Jersey.
- Received June 7, 1983.
- Revision received September 13, 1983.
- Accepted September 19, 1983.
- American College of Cardiology Foundation