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To assess the significance of ST segment shift during the acute phase of non-Q myocardial infarction we studied the clinic echocardiographic, ergometric and coronarographic findings of 46 patients with a first non-Q wave myocardial infarction. The study population was subdivided in 2 subgroups on the basis of acute electrocardiographic change (Group I with ST elevation, Group II with ST depression). Patients with ST elevation had little myocardial infarction with enzymatic (early CPK peak) and coronarographic (low prevalence of coronary occlusion) signs of early spontaneous fibrinolysis. The second group had more diffuse myocardial infraction, higher prevalence of multivessel coronary disease and positive stress test. The ECG changes in this subgroup an probably due to subendocardial necrosis for the presence of collateral flow. The worse intrahospital prognosis of patients with ST segment depression may be related to cardiac function and age.

Early relaxation is characterized by a segmental outward wall movement during isovolumic relaxation. There is still no general agreement as to its significance. Some Authors have considered the phenomenon to be a specific marker of isolated coronary narrowing, others have regarded it as a normal variation of left ventricular relaxation and still others concluded that it is a compensatory phenomenon to local ischemia in another region. We used a method of quantitative assessment of regional left ventricular function and a videodensitometric analysis of coronary stenosis. In our study we didn't observe an improved systolic function of the regions that presented early relaxation, but a slight non significant reduction. We did neither observe any correlation between early relaxation and ischemia provoked by stress test nor between early relaxation and coronary artery disease. The amplitude of early relaxation was not statistically different between patients with and without stenosis of left anterior descending artery. We conclude that early relaxation is a normal variation of left ventricular relaxation.

To assess the relation between the extent of myocardial necrosis and the presence of myocardium at risk in myocardial infarction without Q waves (NQMI) we studied by echocardiography the prevalence of jeopardized myocardium in a group of NQMI stratified on the basis of left ventricular wall motion (akinesis, hypokinesis, normal kinesis). We have studied 60 consecutive patients with non-Q myocardial infarction. Patients were examined by 2D echo at rest (V-VI day from the acute episode) and during symptoms limited bicycle ergometric test (ExT) (XX-XXX day). Regional left ventricular wall motion was evaluated as normal or asynergic (severe hypokinetic, akinetic) and the ExT was considered positive in case of new asynergic areas or ECG criteria. 2D echo at rest was technically satisfactory in 56 patients, 19 showed almost an akinetic segment (Aci) 17 had hypokinetic areas (Ipo) and 20 had normal left ventricle kinesis (Norc). Wall motion abnormalities were localized more frequently in the apex and lateral areas. During exercise 2D echo was performed in 46 patients (82%) with 23 positive tests (50%). Stratifying the population on the basis of left ventricle wall motion we observed a major number of positive tests in the group of patients with normal wall motion in comparison with those with asynergic areas at rest (Norc 66.6%, Ipo 35.7%, Aci 42.6% p less than 0.05 Nore vs Ipo and Nore vs Aci) despite the same CAD extension. These data show the heterogeneity of the NQMI that likely includes patients with transmural (asynergy group) and subendocardial MI (normal kinesis group), the latter with a higher degree of myocardium at risk.