Comparison Of Adenosine Stress And Dobutamine Stress By Real-time Myocardial Contrast Echocardiography In Detecting Myocardium Ischemia In Dogs

Objective： To determine the accuracy of RTPI in assessment of peri-infarct ischemiaduring dobutamine and adenosine stress,by taking infarct size delineated byTriphenyltetrazolium chloride (TTC) stainding for reference.Methods： we employed the RTPI modality (Agilent and ATL Philips) in a caninemodel (18dogs) of distal coronary occlusion and proximal coronary stenosis. Usingcoronary flow probe recordings, the physiologic significance of proximal coronary stenosiswas established by confirming abolition of the coronary reserve. The contrast agent Optionwas given as a slow bolus injection at baseline, during prolonged distal coronary occlusion,during adenosine bolus stress and during dobutamine stress. Triphenytetrazolium chloride(TTC) staining was used to verify a distal infarction. RTPI recording at baseline, the distalcoronary occlusion and stress protocols were randomly mixed and reviewed blindly.Results：The percentage of the small infarct area was (15.4±4.5)%(range from5%to 22%) by TTC staining and (15.1±5.7)%(range from0to22%) by RTPI. The percentageof the peri-infarct ischemia area was (25.3±5.6)%(range from17%to36%) by adenosinestress and (26.3±5.5)%(range from17%to37%) by dobutamine stress. Sensitivity,specificity and overall diagnostic accuracy of adenosine stress were83%,92%and88%,respectively. Sensitivity, specificity and overall accuracy of dobutamine stress were95%,86%and91%,respectively.Conclusion：Even small distal infarcts can be detected by RTPI; peri-infarct ischemiacan be accurately recognized by RTPI during stress; adenosine and dobutamine stressappear equally reliable in the RTPI evaluation of peri-infarct ischemia.