Author + information
- Received May 13, 1991
- Revision received July 10, 1991
- Accepted July 23, 1991
- Published online February 1, 1992.
- Mario S. Verani, MD, FACC∗,
- Jeffrey L. Lacy, PhD,
- Gerald W. Guidry, CNMT,
- Shigeyuki Nishimura, MD,
- John J. Mahmarian, MD,
- Theodoros Athanasoulis, MD and
- Robert Roberts, MD, FACC
- ↵∗Address for reprints: Mario S. Verani, MD, Section of Cardiology, Department of Medicine, Baylor College of Medicine, Nuclear Cardiology, The Methodist Hospital, 6535 Fannin, F-905, Houston, Texas 77030.
To study the functional significance or transient coronary occlusion on systolic and diastolic left ventricular function relative to the anatomic site of occlusion, first-pass radionuclide angiography with a mobile multiwire gamma camera using tantalum-178 (dose activity ≤84 mCi/elution) was performed in 46 patients undergoing balloon coronary angioplasty. First-pass images were acquired immediately before angioplasty and during the last 30 s of a 60-s balloon inflation in 23 left anterior descending arteries, 18 right coronary arteries, 8 circumflex arteries and 5 diagonal coronary arteries.
Occlusion of the left anterior descending artery resulted in significant decreases in left ventricular ejection fraction (54.6 ± 12.7% to 32.3 ± 10.6%, p = 0.0001) and peak filling rate (2.48 ± 0.68 to 1.75 ± 0.64 end-diastolic volumes/s, p = 0.0001), accompanied by severe abnormalities in regional function and left ventricular dilation. Right coronary artery occlusion caused inferior hypokinesia, but did not significantly change left ventricular ejection fraction (48.5 ± 12.4% vs. 45.8 ± 12.5%, p = NS) or peak filling rate (2.05 ± 0.81 vs. 2.09 ± 0.81 end-diastolic volumes/s, p = NS). Circumflex artery occlusion resulted in mild wall motion deterioration and a borderline decrease in ejection fraction (54.7 ± 11.4% to 50.5 ± 12%, p = 0.057). Diagonal artery occlusion did not cause significant changes in left ventricular ejection fraction or filling rate. The decrease in left ventricular ejection fraction during coronary occlusion was 9 ± 25% and 27 ± 22%, respectively, in those arteries with and without collateral supply (p = 0.052).
These data provide strong evidence for the critical importance of the left anterior descending artery and the secondary role of the other coronary arteries in maintaining global systolic and diastolic left ventricular function and suggest a protective role of collateral vessels during coronary occlusion.
☆ This, study was presented in part at the 40th Annual Meeting of the American College of Cardiology, Atlanta, Georgia, March 1991, and at the 37th Annual Meeting of the Society of Nuclear Medicine, Washington, DC, June 1990. Computational assistance was provided by the CLINFO project, Houston, which is funded by Grant RR-00350 from the Division of Research Resources of the National Institutes of Health, Bethesda, Maryland.
- Received May 13, 1991.
- Revision received July 10, 1991.
- Accepted July 23, 1991.