Faculty Collaboration Database

Intramyocardial variability in integrated backscatter: effects of coronary occlusion and reperfusion. Circulation 1987 Feb;75(2):436-42

Date

02/01/1987

Pubmed ID

3542284

DOI

10.1161/01.cir.75.2.436

Abstract

The present study was undertaken to characterize regional myocardial alterations of reflected ultrasound during the cardiac cycle in normal, ischemic, and postischemic reperfused myocardium. Time-averaged integrated backscatter (IB) and cardiac cycle-dependent amplitude modulation were measured from subepicardial, midmyocardial, and subendocardial regions of the left ventricular apex and the midportion of the right ventricular free wall under normal conditions (n = 5), after 1 hr of 100% acute left anterior descending (LAD) occlusion (n = 8), and after 15 min LAD occlusion plus 120 min reperfusion (n = 5) in anesthetized, ventilated open-chest dogs. A significant increase in time-averaged IB was observed in the subepicardium, the midmyocardium, and the subendocardium during ischemia and reperfusion, but there was no intramyocardial variability. Cardiac cycle-dependent amplitude modulation of IB was significantly higher in the normal subendocardium than in the subepicardium (4.3 +/- 0.6 vs 2.9 +/- 0.8 dB, p less than .01) and midmyocardium (2.8 +/- .05 dB, p less than .01). This transmural gradient in amplitude modulation was abolished during ischemia and reperfusion. We conclude that cardiac cycle-dependent amplitude modulation in IB has a transmural dependence in the normal myocardium and this is abolished during acute myocardial ischemia.

Author List

Sagar KB, Rhyne TL, Warltier DC, Pelc L, Wann LS

Author

David C. Warltier PhD Emeritus Professor in the Anesthesiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Coronary Disease
Dogs
Female
Heart
Male
Myocardial Contraction
Myocardium
Ultrasonography