Myocardial Perfusion in Acute Coronary Syndrome
Venous myocardial contrast echocardiography is a new method for myocardial perfusion imaging. It has been shown to accurately evaluate risk area and infarct size in the experimental setting of acute myocardial infarction and has recently become clinically available. We used this method to assess myocardial salvage after coronary reperfusion in a patient with acute coronary syndrome.
A 68-year-old man with known single-vessel coronary artery disease presented with 6 hours of moderate chest pain typical of unstable angina. Four years earlier, a percutaneous transluminal coronary angioplasty of the left anterior descending coronary artery had been performed; the patient was asymptomatic throughout the following years. On admission, the 12-lead ECG showed atrial fibrillation and descending ST-segment depression up to 0.25 mV in leads V3 through V6. Cardiac enzymes, including troponin I, were normal at that time. After medical treatment with heparin, nitroglycerin, β-blocker, and aspirin, the chest pain and ECG changes resolved completely. Eight hours later, the patient reported reoccurrence of mild chest pain; by then, troponin I was elevated, at 0.8 ng/mL. Cardiac imaging at rest with venous myocardial contrast echocardiography (digitally processed and color-coded echocardiographic images, Figure⇓, A) and 99mTc-sestamibi single photon emission computed tomography (SPECT; B) showed perfusion defects of the basal inferior left ventricular wall. On cardiac catheterization, a subtotal occlusion of the left circumflex coronary artery (C) was seen, and uncomplicated stenting of the lesion was performed (F). Creatine kinase reached a maximum of 256 U/L (MB fraction, 34 U/L) during the next day. After 7 days, venous myocardial contrast echocardiography (D) and 99mTc-sestamibi SPECT (E) were repeated and demonstrated almost complete reperfusion of the inferior left ventricular wall. The patient was discharged 10 days after admission.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to Dr Hugh A. McAllister, Jr, St Luke’s Episcopal Hospital and Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.
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