Immediate diagnosis of acute myocardial infarction by two-dimensional echocardiography.

Abstract

SUMMARY To define the role of portable two-dimensional echocardiography (2-D echo) in the immediate diagnosis of acute chest pain syndrome, 80 consecutive patients were studied. Adequate 2-D echo studies were obtained in 65 (81%). Thirty-three patients had clinical evidence of transmural or nontransmural acute myocardial infarction (AMI), 18 infarction, which correlate well with pathologic data and with the site of infarction on the ECG. The purpose of this study was to investigate the role of twodimensional echocardiography in the immediate diagnosis of acute myocardial infarction in patients who present with acute chest pain to the emergency room. Materials and MethodsThe study population consisted of 80 consecutive patients with a symptom complex of prolonged chest discomfort occurring within 12 hours of admission to an intensive care unit. Patients with valvular heart disease, previous myocardial infarction, cardiomyopathy or significant periocardial effusion were excluded by clinical history, physical examination or echocardiography. M-mode and two-dimensional echocardiograms were obtained within 8 hours of admission. Fifty-four males and 26 females, ages 32-85 years, were studied. Myocardial infarction was diagnosed by a typical history of chest pain along with either characteristic electrocardiographic changes or a rise in serum CK-MB. ECGs were performed at least once daily and CK-MB was measured every 8 hours for the first 24 hours and then daily for at least 2 days. CK-MB was performed by the cellulose acetate electrophoretic method. A transmural myocardial infarction was diagnosed by the development of new Q waves > 0.04 second in more than one lead or an R: S ratio > 1 in lead V1 or V2 with at least abnormal repolarization in the inferior leads. A nontransmural myocardial infarction was diagnosed by an elevation of CK-MB enzyme without necessitating important ECG changes or classic evolution of deep symmetric T-wave inversions. The infarction was considered inferior if the Q waves or symmetrically inverted T waves occurred in leads 2, 3, or aVF; anterior if in leads V1-V,; and lateral if in leads 1, aVL or V,-V,.The clinical course was monitored in the intensive care unit and thereafter. A cardiac complication was

Two-dimensional ultrasonic tissue characterization: backscatter power, endocardial wall motion, and their phase relationship for normal, ischemic, and infarcted myocardium.

“…Many investigators have observed qualitative regional wall motion abnormalities by echocardiography during acute myocardial ischemia. [1][2][3][4] Over the last 7 years much effort has been directed toward quanti-LABORATORY INVESTIGATION-ECHOCARDIOGRAPHY of endocardial excursion at end-diastolic and end-systole may fail to detect important wall motion abnormalities. Blumenthal et al 16 showed that wall motion abnormalities may persist long after transient ischemia, even when myocardial blood flow is reestablished and histology is normal.…”

Diretrizes

“…A ecocardiografia constitui importante subsídio, tanto para a elucidação diagnóstica como para a avaliação do prognóstico após infarto agudo do miocárdio 115,116 .…”

III Diretriz sobre tratamento do infarto agudo do miocárdio

“…A ecocardiografia constitui importante subsídio tanto para a elucidação diagnóstica como para a avaliação do prognóstico após-IAM 137,138 .…”