Comparison of adenosine stress and dobutamine stress by real-time myocardial contrast echocardiography in detecting myocardium ischemia in dogs.
BACKGROUND
Real-time perfusion imaging (RTPI) using ultrasound contrast agents has shown good "accuracy" in detecting myocardial infarction, however its accuracy in the assessment of peri-infarct ischemia and stress echocardiography are not known. The aim of this study was to determine the accuracy of RTPI in assessment of peri-infarct ischemia during dobutamine and adenosine stress.


METHODS
We employed the RTPI modality (Agilent and ATL Philips) in a canine model (18 dogs) of distal coronary occlusion and proximal coronary stenosis. Using coronary flow probe recordings, the physiologic significance of proximal coronary stenosis was established by confirming abolition of the coronary reserve. The contrast agent Optison was given as a slow bolus injection at baseline, during prolonged distal coronary occlusion, during adenosine bolus stress and during dobutamine stress. Triphenyltetrazolium chloride (TTC) staining was used to verify a distal infarction. RTPI recordings at baseline, the distal coronary occlusion and stress protocols were randomly mixed and reviewed blindly.


RESULTS
In all but one dog, RTPI detected a distal infarct as small as 9% of the left ventricle. The sensitivity, specificity and overall diagnostic accuracy of RTPI in the detection of distal infarcts were: 94%, 89% and 92%, respectively. The sensitivity, specificity, and overall diagnostic accuracy of RTPI in the assessment of peri-infarction ischemia were 83%, 92% and 88% for adenosine stress and 95%, 86% and 91% for dobutamine stress, respectively.


CONCLUSIONS
Even small distal infarcts can be detected by RTPI; peri-infarct ischemia can be accurately recognized by RTPI during stress; adenosine and dobutamine stress appear equally reliable in the RTPI evaluation of peri-infarct ischemia.
Xing
Yan-qiu
YQ
Department of Geriatrics, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China. Xingyanqiu@sina.com
Hou
Bo-wen
BW
Zhang
Yun
Y
Liu
Xiang-qun
XQ
Gao
Hai-qing
HQ
D000241:Adenosine / Q000633:toxicity*; D000818:Animals; D003326:Coronary Circulation / Q000187:drug effects; D004280:Dobutamine / Q000633:toxicity*; D004285:Dogs; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*
D004280:Dobutamine; D000241:Adenosine