Characterization of nontransmural myocardial infarction by positron-emission tomography.

Abstract

SUMMARY The present study was performed to determine whether positron emission tomography (PET) performed after i.v. '1C-palmitate permits detection and characterization of nontransmural myocardial infarction. PET was performed after the i.v. injection of 1'C-palmitate in 10 normal subjects, 24 ture and anatomic distribution of injury with nontransmural compared with transmural myocardial infarction. Materials and Methods PatientsAll 56 subjects gave informed written consent. The group included 10 normal subjects (six males and four females, average age 39 years, range 23-68 years) and 46 patients who had survived acute myocardial infarction for at least 72 hours. Control subjects were seven normal volunteers without a history of chest pain or myocardial infarction and with normal physical examinations and three patients admitted to the coronary care unit for the evaluation of atypical chest pain in whom myocardial infarction was excluded based on serial electrocardiographic and enzymatic criteria. None of the controls had experienced previous myocardial infarction or exhibited Q waves on the ECG.The 46 patients (31 male, 15 female, mean age 57 years, range of 29-84 years) experienced myocardial infarction documented by a history of precordial chest pain of at least 20 minutes duration and serial elevations of total and MB plasma CK. Demographic data are summarized in table 1.Patients with myocardial infarction preceding the index episode were excluded. Transmural myocardial infarction was considered to be present if Q waves of 30 msec duration were seen in recordings from at least two concordant leads. In the absence of these criteria, nontransmural myocardial infarction was considered to be present. Infarction was transmural in 22 and nontransmural in 24 patients. Radiochemicals and Tomographic ProceduresThe "IC-palmitate was prepared with a synthesis developed at Washington University that involves the addition of "CO2 produced in the medical center cyclotron to a Grignard reagent (I-MgBr-pentade-

Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction: Role of magnetic resonance imaging

“…The pharmacologic approach (echocardiography with dobutamine) is stilI under investigation.3 Among the noninvasive cardiac imaging techniques, only positron emission tomography (PET) has proven adequate for distinguishing between reversible and irreversible ischemic tissue injury. [4][5][6] The combined evaIuation of blood flow and glucose utilization aims to identify compromised but viable myocardium when waIl motion is equaIly impaired in necrotic and reversibly damaged tissue.…”

Assessment of Myocardial Metabolism with 11C-palmitate. Comparison with 123I-heptadecanoic acid

“…In the case of electrocardiographically defined non-transmural infarction the sensitivity of PET is considerably higher than conventional scintigraphy with thallium-201 in the same patients' 10 '. Tomographic defect size correlated closely with infarct size estimated from serial plasma MB-CK.…”

Imaging of myocardial fatty acid oxidation

“…PET imaging in ischemia finds clinical utility in the estimation of infarct size, and more specifically in distinguishing viable from non-viable regions in the infarcted zone [34, 41, 42, 50–62]. PET measures of blood flow in ischemia can provide prognostic information [58, 63], and some have even argued that a PET-derived metabolic definition of infarct is superior to other imaging approaches [64].…”