Author + information
- Received November 9, 1987
- Revision received February 17, 1988
- Accepted March 8, 1988
- Published online August 1, 1988.
- Andrew J. Feiring, MD, FACC∗,1,
- John A. Rumberger, PhD, MD1,
- Steven J. Reiter, MD,
- Steve M. Collins, PhD,
- David J. Skorton, MD, FACC2,
- Michael Rees, MD and
- Melvin L. Marcus, MD, FACC
- ↵∗Present address and address for reprints: Andrew J. Feiring, MD, Division of Cardiology, University of Wisconsin, Milwaukee, Clinical Campus, 950 North Twelfth Street, Room G-222, P.O. Box 342, Milwaukee, Wisconsin 53201.
In this study, ultrafast computed tomography, a new high spatial and temporal resolution imaging system, was employed to define the range of sectional (tomographic) and segmental left ventricular function in 11 normal anesthetized dogs and 11 normal human volunteers. After intravenous infusion of contrast agent, multilevel tomographic images of the left ventricle (apex to base) were acquired at a rate of 17 frames/s. Analysis of these studies demonstrated substantial but predictable heterogeneity in left ventricular contraction from apex to base. In dogs and humans, for example, the average tomographic ejection fraction of the most basal level of the left ventricle was 40% less than that of the most apical level (p < 0.05).
In humans, circumferential segmental cavity contraction at the mid-papillary muscle level was relatively homogeneous (range 50 to 92% for 12 wedge-shaped segments around the tomographic circumference) if the reference system employed an endocardial centroid, but was less uniform if it used an epicardial centroid (range 22 to 98%).
It is concluded that contraction of the normal left ventricle in dogs and humans is heterogeneous both between levels (apex to base) and within a single level (circumferential cavity contraction). However, the patterns of cavity contraction from apex to base and circumferential segmentai cavity contraction within a given level as defined by ultrafast computed tomography are sufficiently narrow and predictable in normal individuals that these variables may be useful to define regional contraction abnormalities in pathologic conditions.
↵1 Drs. Feiring and Rumberger are recipients of Clinician Scientist Award from the American Heart Association, Iowa Affiliation, Iowa City, Iowa.
↵2 Dr. Skorton is a recipient of Research Career Development Award K04-HL01290 from the National Heart, Lung, and Blood Institute, National Institutes of Health.
☆ This study was supported by Grants HL20827, Ischemic SCOR HL32295 and PPG HL-14388-145 from the National Institutes of Health, Bethesda, Maryland and support from Imatron, Inc., South San Francisco, California.
- Received November 9, 1987.
- Revision received February 17, 1988.
- Accepted March 8, 1988.