Clinical significance of inferior ST elevation during acute anterior myocardial infarction.

Abstract

Objectives-To clarify the genesis and clinical significance of inferior ST elevation during acute anterior myocardial infarction. Patients and design-A total of 106 patients with first acute anterior myocardial infarction (< 6 h) were divided into two groups according to the presence (group A, n = 12) or absence (group B, n = 94) of ST elevation of > 1 mm in at least two of the inferior leads on the admission electrocardiogram. Results-On admission electrocardiograms, group A had a smaller summed ST deviation in the lateral limb leads than group B. On emergency coronary arteriograms, the incidence of a wrapped left anterior descending artery was higher in group A than in group B (100% v 27%, P < 0.01). The incidence of occlusion of a left anterior descending artery distal to its first diagonal branch was higher in group A than in group B (100% v 46%, P < 0*01).Peak serum creatine kinase activity and in-hospital mortality tended to be lower in group A than in group B. Group A had better left ventricular ejection fraction and regional wall motion in the anterobasal and anterolateral regions in the chronic phase than group B. In contrast, regional wall motion in the diaphragmatic region was reduced to a greater extent in group A than in group B. Conclusions-Inferior ST elevation during acute anterior myocardial infarction appears only in the presence of a combination of a lesser degree of transmural ischaemic myocardium in the anterobasal and anterolateral wall together with transmural ischaemic myocardium in the inferior wall; in all cases there was occlusion of a wrapped left anterior descending artery distal to its first diagonal branch. Patients with such an ST elevation appear to have a better in-hospital prognosis than those without it. (Br HeartJ' 1995;74

Clinical Implications of Serial Changes in ST-Segment Elevation After Reperfusion in Patients With Anterior Acute Myocardial Infarction

“…Third, the presence of ischemia in the non-infarcted area might influence the degree of ST-segment deviation in the infarcted area on the admission ECG. 31 However, the rates of multivessel disease were not significantly different among the 3 groups.…”

Specific Findings of the Standard 12-Lead ECG in Patients With 'Takotsubo' Cardiomyopathy-Comparison With the Findings of Acute Anterior Myocardial Infarction-

“…[9][10][11][12] In addition, Raitt et al 13 postulated that acute ischemia in regions supplied by the proximal left anterior descending coronary artery can cause local intramyocardial conduction delays, resulting in early abnormal Q wave formation. On the basis of these observations, we postulate that the lack of reciprocal changes and abnormal Q waves in the setting of 'Takotsubo' cardiomyopathy might be explained by the fact that myocardial dysfunction is confined to the apical wall, and therefore the ST-segment elevations are greater in leads V4-6 than in leads V1-3.…”

Differentiation Between Patients With Takotsubo Cardiomyopathy and Those With Anterior Acute Myocardial Infarction

“…The ST-segment in the inferior leads is elevated in some patients with anterior AMI and a smaller infarct and wrapped LAD, 10,14,15 and it might be difficult to distinguish TC from anterior AMI, particularly when the culprit lesion is in the distal LAD.…”

“…[1][2][3][4][5][6][7] The absence of reciprocal changes, absence of abnormal Q waves, and ∑ST V4-6/∑ST V1-3 >1 have been reported as having high sensitivity and specificity for distinguishing TC from anterior AMI. 3 However, it has been hypothesized that the ECG findings of anterior AMI depend on the site of the culprit lesion and the presence of a wrapped LAD, [8][9][10][11][12][13][14][15] and therefore, we divided the present patients with an anterior AMI into groups according to the site of the culprit lesion and compared their ECG findings with those from patients with TC.…”