Evaluation of reperfusion hyperemia with myocardial contrast echocardiography.
In this study we used myocardial contrast echocardiography to evaluate reperfusion hyperemia in an open-chest canine model of temporary coronary artery occlusion. Eight dogs had coronary occluders and electromagnetic flow probes on the left circumflex coronary artery. Aortic root injections of agitated sodium diatrizoate and saline solution were used for myocardial contrast. Data were collected at baseline (n = 16), during coronary occlusion (n = 18), immediately after coronary release (n = 18), and 5 minutes after coronary artery release (n = 12). Baseline coronary flow was 23.8 +/- 5.9 ml/min, decreasing to 0 ml/min during coronary occlusion. Immediately after coronary release flow was 96.6 +/- 41 ml/min (p less than 0.001 compared with baseline), and 5 minutes after coronary release flow was 68.2 +/- 27.9 ml/min (p less than 0.001 compared with baseline). The myocardial image intensity change after injection of contrast material was 74.25 +/- 30.6 ml/min at baseline and declined to 10.4 +/- 10.9 ml/min during coronary occlusion (p less than 0.001 compared with baseline). During reperfusion hyperemia image intensity change was 102.3 +/- 33.3 ml/min (p less than 0.001 compared with occlusion, p less than 0.02 compared with baseline, p less than 0.001 compared with remote regions). Considering all observations, myocardial image intensity change after contrast injection correlated positively with coronary flow (r = 0.67, p less than 0.001). Correlations within individual dogs ranged from r = 0.70 to 0.98. We conclude that image intensity change after aortic root injection of echocardiographic contrast correlates with coronary blood flow. Objective measurements of contrast intensity reflect increases in coronary flow associated with reactive hyperemia after coronary occlusion and release.
Armstrong
W F
WF
Wishard Memorial Hospital, Krannert Institute of Cardiology, Indianapolis, IN 46202.
Gage
S W
SW
D000818:Animals; D003326:Coronary Circulation / Q000502:physiology*; D003327:Coronary Disease / Q000503:physiopathology*; D003973:Diatrizoate; D004285:Dogs; D004452:Echocardiography; D004582:Electronics, Medical / Q000295:instrumentation; D005260:Female; D006940:Hyperemia / Q000175:diagnosis*; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis*; D015588:Observer Variation; D012212:Rheology
D003973:Diatrizoate