Author + information
- Received July 16, 1982
- Revision received October 19, 1982
- Accepted October 25, 1982
- Published online March 1, 1983.
- Marco A.R. Torres, MD,
- Eliot Corday, MD, FACC*,
- Samuel Meerbaum, PhD, FACC,
- Tatsuo Sakamaki, MD,
- Thomas Peter, MD and
- Takahisa Uchiyama, MD, FACC
- ↵*Address for reprints: Eliot Corday, MD, Halper Research Building, Cedars-Sinai Medical Center, 8700 Beverly Boulevard. Los Angeles, California 90048.
Two-dimensional echocardiography was applied experimentally in a closed chest dog model with intact pericardium to determine the location, magnitude and extent of contractile response during pacing from discrete ventricular sites. Mid ventricular short-axis tomographic images obtained during regular sinus rhythm and subsequent premature ventricular beats provided comparative measurements of global and segmental systolic changes of cross-sectional luminal areas and myocardial wall thickness. Computer-assisted standardized analysis of segmental systolic fractional area change and wall thickening was used to map left ventricular contraction during normal rhythm and premature beats of 70% coupling interval, induced alternately from anterior and lateral aspects of the mid-left ventricular short-axis cross-sectional plane.
A characteristic pattern consisting of early systolic contraction and wall thickening was followed by paradoxical motion and wall thinning in late systole in segments corresponding to the region of direct electrical stimulation. Statistical analysis of segment by segment function indicated a maximal amount of premature beat contractile derangement at the site of the stimuli. Pacing from a right ventricular wall site in the midventricular plane caused a similar premature beat response at the anterior aspect of the interventricular septum.
It is concluded that two-dimensional echographic analysis of segmental ventricular function can identify the location of electrical stimuli, and thus might non-invasively characterize regional patterns of contraction associated with ectopic foci during arrhythmias.
This study was supported in part by Grants HL 17651-07 and 08 and HL14644-09 from the National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland and the Ah-manson, W.M. Keck. Nicolai Joffe and Lillian D. Truyens Foundations, Los Angeles; Mrs. Anna Bing Arnold, Mr. and Mrs. William Black-field, Mr. Theodore Cummings and Mr. and Mrs. E. E. Fogelson, Mrs. Florence Hamilton, Mr. and Mrs. Randolph Scott, and Mrs. Elizabeth Corday
- Received July 16, 1982.
- Revision received October 19, 1982.
- Accepted October 25, 1982.
- American College of Cardiology Foundation