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Background: Both 2-dimensional echocardiography and myocardial perfusion imaging (MPI) with technetium-99m based agents have been used to identify patients in the emergency department with myocardial infarction (MI). However, the inclusion of small numbers of patients in prior studies limits the accurate assessment of sensitivity of the 2 techniques., Methods: Gated MPI was used as part of the initial triage process in patients initially considered at low to moderate risk for acute coronary syndromes (no ST elevation or depression). Patients diagnosed with MI also underwent echocardiography. MPI results were considered positive if there was a perfusion defect associated with abnormal wall motion or thickening, and echocardiographic results were considered positive if there were segmental wall motion abnormalities or ejection fraction of less than 40%., Results: Both tests were performed on 141 patients. The sensitivities for MI for echocardiography (91%; 95% CI, 86%-95%) and MPI (89%; 95% CI, 83%-94%) were similar. Patients who had either negative echocardiographic results (peak creatine kinase level [CK], 325 +/- 206 vs 582 +/- 614 U/L; P =.003) or negative MPI results (peak CK, 313 +/- 227 vs 590 +/- 620 U/L; P =.001) had smaller MIs as estimated with peak CK values. Ejection fraction was highly correlated between the 2 techniques (r = 0.82; P <.001)., Conclusion: Both echocardiography and MPI have a high sensitivity for identifying patients in the emergency department who have MI. False negative studies with either technique were associated with small MIs.

Background: Accurate identification of patients at high risk for acute coronary syndromes among those seen in the emergency department (ED) with possible myocardial ischemia and nonischemic electrocardiograms is problematic. Both 2-dimensional echocardiography and myocardial perfusion imaging with technetium-99m sestamibi can identify patients at low and high risk; however, comparative studies are lacking., Methods and Results: Patients initially considered at low or moderate risk for myocardial ischemia on the basis of the presenting history, physical examination, and electrocardiogram underwent both echocardiography and myocardial perfusion imaging within 4 hours of ED presentation. Positive echocardiography was defined as the presence of segmental wall motion abnormalities or moderate to severe global systolic dysfunction; positive perfusion imaging was defined as a perfusion defect in association with abnormal wall motion, thickening, or both. End points included MI, percutaneous transluminal coronary angioplasty, and positive stress perfusion imaging. Both imaging procedures were performed in the ED on 185 patients. Six patients had MI, and an additional 4 patients underwent percutaneous transluminal coronary angioplasty. Echocardiography and perfusion imaging were positive in all 10. Overall agreement between the 2 techniques was high (concordance 89%, kappa coefficient 0.74) in the 27 patients who had MI or underwent coronary angiography. For all patients, concordance was 89%, with a kappa coefficient of 0.66., Conclusions: Agreement between echocardiography and perfusion imaging with technetium-99m sestamibi is high when used in patients in the ED with possible myocardial ischemia. Both techniques identified patients at high risk who required admission and those who could be safely discharged directly from the ED.

Evidence that non-Q-wave myocardial infarction (MI) is an unstable or incomplete cardiac syndrome is clear. Morphologic findings, coronary pathoanatomy, in-hospital complication rates, risk-stratification data, postdischarge mortality data, and particularly morbidity data indicate a need for close diagnostic evaluation and careful long-term follow-up. Thrombolytic therapy appears to be ineffective in patients with non-Q-wave MI. Measures to prevent reinfarction during the hospital stay are indicated. Any complication of non-Q-wave MI is an indication for cardiac catheterization. All patients with non-Q-wave MI require predischarge risk stratification. If they cannot be stratified by clinical or electrocardiographic characteristics, exercise stress testing is required, preferably with an imaging study. When stratification indicates high risk, predischarge cardiac catheterization is required.

The effect of percutaneous transluminal coronary angioplasty (PTCA) on left ventricular (LV) diastolic function has not been systematically investigated in patients treated for unstable angina or ischemia after acute myocardial infarction (AMI). To assess the relation between reduction of stenosis severity and improvement in diastolic function in this setting, 42 patients with either unstable angina (n = 22) or post-AMI ischemia (n = 20) were serially monitored by Doppler echocardiography 8 +/- 5 hours before and 2 +/- 1 days after PTCA. Doppler LV filling indexes included isovolumic relaxation time, mitral deceleration time, E/A peak velocity ratio and atrial filling fraction. Eighteen aged-matched control subjects served to establish normal values for comparison. Before PTCA, both groups exhibited abnormal diastolic function demonstrated by prolonged isovolumic relaxation time and mitral deceleration time, decreased E/A ratio and increased atrial filling fraction. After PTCA isovolumic relaxation time and deceleration time decreased 18 +/- 28 (p less than 0.005) and 33 +/- 43 ms (p less than 0.002) in the unstable angina group and 18 +/- 23 (p less than 0.003) and 14 +/- 34 ms (difference not significant), respectively, in the post-AMI ischemia group. An increase in E/A ratio and a decrease in atrial filling fraction occurred in both groups; however, these changes were significant only in patients with post-AMI ischemia (+21%, p less than 0.03 and -11.4%, p less than 0.005, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Perhaps the most important point concerning right ventricular myocardial infarction is to be alert for its occurrence. Approximately one fifth of all infarctions and one third of all inferior infarctions have some right ventricular involvement. All right ventricular infarcts are probably associated with inferior left ventricular infarctions. The correct diagnosis alters the treatment of a patient with a low cardiac-output state that complicates the acute infarction. The prognosis after a right ventricular myocardial infarction would seem to be related to the degree of left ventricular dysfunction associated with the original infarction.

The rationale for introducing the term "non-Q-wave myocardial infarction" is identified. The incidence, pathology, pathogenesis, and diagnostic criteria for this condition, previously identified as nontransmural or subendocardial infarction, are reviewed. In reviewing the diagnostic criteria, the various noninvasive techniques that may be applied are discussed. The clinical course, prognosis, and management are discussed under the headings of early postinfarction period, late clinical course, predischarge evaluation, and long-term care. The issues of the management of infarct extension and acute interventional therapy are raised and reviewed. Suggestions regarding specific aspects of therapy in non-Q-wave myocardial infarction are included in the summary.

To determine whether real-time two-dimensional echocardiography (2-D echo) can estimate the extent of myocardial involvement in patients with acute myocardial infarction (MI), regional wall motion on serial short-axis 2-D echo recordings was analyzed and the summed scores were compared with estimates of infarct involvement by thallium-201 reperfusion (Tl) and technetium-99m stannous pyrophosphate (99mTc-PYP) scintigraphy. Thirty-two consecutive male patients admitted with their first MI were studied; 10 patients had anterior, 16 had inferior and six had subendocardial MIs. Two patients were technically unsuitable for 2-D echo studies. Twenty patients had Tl scintigrams and 29 had 99MTc-PYP scintigrams. Summed 2-D echo scores correlated closely with estimates of infarct involvement by Tl (r = 0.87) and with estimates of infarct size by 99mTc-PYP (r = 0.74). The location of MI by 2-D echo agreed with the electrocardiographic location in 26 of 29 patients; discrepancies occurred in one inferior and two subendocardial MIs. Predischarge 2-D echo failed to identify extension of transmural infarction. However, two patients whose subendocardial MIs progressed to transmural MIs were identified. This study shows that 2-D echo is a valid method for the early estimation of the extent of myocardial involvement in patients with acute MI, especially transmural MIs. In particular, 2-D echo correlates closely with Tl reperfusion scintigraphy because both detect areas of ischemia and infarction.