BACKGROUND: Inferior myocardial infarctions account for 40-50% of all acute myocardial infarctions and are generally viewed as having a more favorable prognosis than anterior wall infarctions. However, nearly 50% of patients suffering inferior infarction will have complications such as heart block, concomitant precordial ST-segment depression and right ventricular infarction or distinguishing features associated with an increased mortality that will substantially alter an otherwise favorable prognosis. METHODS: Clinical characteristics, electrocardiograms, and angiographic findings of coronary artery were viewed in 47 patients with inferior myocardial infarction. Significant ST-segment change was defined as > or =0.1mV horizontal or down sloping depression in acute inferior myocardial infarction patients with ST-segment elevation on leads II, III, aVF measured with reference to the TP segment, 80ms after J point. A group=no precordial ST-segment depression. B group=sum of ST-segment depression in leads V1 to V3 equal to or more than the sum of ST-segment depression in leads V4 to V6. C group=maximal precordial ST-segment depression in leads V4 to V6. RESULTS: 1) Incidence of multi-vessel disease in group A and in group B were 23% and 22%, respectively, compared with 60% for those of group C(p<0.05). 2) Incidence of Killip class III and IV rates in patients with group A and B were 8% and 12%, respectivly, compared with 47% for those patients with group C(p<0.05). 3) No significant difference of sex, age, peak CK level were found among three groups(p>0.05). CONCLUSION: The patients with acute inferior myocardial infarction with the maximal ST-segment depression in leads V4 to V6 would be at high risk for congestive heart failure and multi-vessel disease.
Coronary Vessels ; Depression* ; Electrocardiography ; Heart Block ; Heart Failure ; Humans ; Incidence ; Infarction ; Inferior Wall Myocardial Infarction* ; Mortality ; Myocardial Infarction ; Prognosis

BACKGROUND: Reciprocal ST-segment depression in precordial leads is a common finding in acute inferior myocardial infarction. The responsible mechanism and the significance of this finding, however, are still controversial. METHODS: From January 1991 to December 1994, 38 patients with acute inferior myocardial infarction were treated at the Department of Internal Medicine in Kyung Hee University Hospital. Clinical characteristics, serial electrocardiograms, and angiographic findings of coronary artery and left ventriculography, echocardiography were reviewed. Reciprocal ST-segment depression was defined as ST-segment depression>or=1.0mm in two or more adjacent precordial leads(V1-V3) in patients with acute inferior myocardial infarction showing ST-segment elevation in II, III, aVF. Coronary angiography and echocardiography were performed within 24 hours from admission. In this study, angiographic distribution score was used to define the perfusion territory causing inferior ischemia. RESULTS: 1) The summation of ST-segment elevation in II, III, aVF leads was significantly more higher in group H than group A (P<0.05). 2) However, the angiographic distribution score, peak CK levels, in-hospital complications and ejection fraction showed no difference between two groups (P>0.05). 3) There were no evidence of anterior wall motion abnormality in two groups. CONCLUSIONS: Our results suggest that the S'I'- segment depression on the precordial leads in acute myocardial infarction can be explained mainly by benign reciprocal electrical change.
Coronary Angiography ; Coronary Vessels ; Depression* ; Echocardiography ; Electrocardiography ; Humans ; Inferior Wall Myocardial Infarction* ; Internal Medicine ; Ischemia ; Myocardial Infarction ; Perfusion