Dipyridamole echocardiography evaluation of acute inferior myocardial infarction with concomitant anterior ST segment depression

The electrocardiogram in ST elevation acute myocardial infarction: correlation with coronary anatomy and prognosis

The electrocardiogram is considered an essential part of the diagnosis and initial evaluation of patients with chest pain. This review summarises the information that can be obtained from the admission electrocardiogram in patients with ST elevation acute myocardial infarction, with emphasis on: (1) prediction of infarct size, (2) estimation of prognosis, and (3) the correlations between various electrocardiographic patterns and the localisation of the infarct and the underlying coronary anatomy.

Influence of thrombolytic therapy on inferior acute myocardial infarction with concomitant anterior ST segment depression

The purposes of this study were to analyze the prognostic significance of precordial ST segment depression and to determine whether thrombolytic therapy is effective for all patients with inferior acute myocardial infarction (AMI) or whether there is a different effectiveness for patients with concomitant anterior ST segment depression persisting for 24 hours or longer. Medical charts of 176 patients were studied. On the basis of ECG the patients were subclassified into three groups according to the presence, persistence, or absence of significant ST segment depression: Group 1: anterior ST segment depression persisting for less than 24 hours (45.4%); Group 2: anterior ST segment depression persisting for more than 24 hours (17.6%); Group 3: no anterior ST segment depression (37%). Age, Killip class, peak creatine kinase, hospital deaths, left ventricular ejection fraction, regional wall motion score, postinfarction angina, and ventricular/supraventricular arrhythmia of all patients were studied. Parameters of the three groups were compared: worse results were found in group 1 and the worst in group 2. This result is independent of thrombolytic therapy. Finally, the same parameters of thrombolyzed and nonthrombolyzed groups were compared: no statistically significant difference was observed. Among thrombolyzed patients the number of those with ST depression lasting more than 24 hours is lower than in nonthrombolyzed patients. It can be assumed that thrombolytic therapy in inferior AMI determines a shifting of patients from a worse prognosis group (ST segment depression persisting for more than 24 hours) to a better prognosis group (ST segment depression persisting for less than 24 hours).

Usefulness of ST-segment depression in non-infarct-related electrocardiographic leads in predicting prognosis after thrombolytic therapy for acute myocardial infarction

This study investigated both the in-hospital and long-term prognostic significance of ST-segment depression in non-infarct-related leads in patients who received thrombolytic therapy after acute myocardial infarction (AMI). We evaluated 221 consecutive patients who were admitted with their first AMI and underwent thrombolysis. Patients were followed for an average of 31 months and were classified into 3 groups: group 1 included 51 patients with persistent ST-segment depression, group 2 had 97 patients with transient ST-segment depression, and group 3 consisted of 73 patients without ST-segment depression (absent). Group 1 had significantly worse long-term survival during follow up by Kaplan-Meier analysis (55%) versus group 2 (81%) and group 3 (94%) (p = 0.0004) and higher event rates. This prognostic significance seemed to be maintained in both the anterior and inferior wall AMI groups. Multivariate analysis, using the Cox model, showed that Killip class, in-hospital left ventricular ejection fraction, and the persistence of ST-segment depression on the predischarge electrocardiogram (group 1) were independent predictors of survival. ST-segment depression in non-infarct-related leads on the predischarge electrocardiogram is an independent risk factor for worse long-term survival after anterior as well as inferior AMI treated with thrombolytic therapy.

Prognostic significance of precordial ST segment depression during inferior myocardial infarction in the thrombolytic era: results in 16,521 patients

OBJECTIVES

We examined the prognostic significance of precordial ST segment depression among patients with an acute inferior myocardial infarction.

BACKGROUND

Although precordial ST segment depression has been associated with a poor prognosis, this correlation has not been adequately quantified, partly because of small sample sizes and methodologic limitations in previous studies.

METHODS

We examined the clinical and angiographic outcomes of 16,521 patients with an acute inferior myocardial infarction who underwent thrombolysis in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) study. Patients were classified into those without precordial ST segment depression (n = 6,422 [38.9%]), those with ST segment depression in leads V1 to V3 only (n = 5,850 [35.4%]), those with ST segment depression in leads V4 to V6 only (n = 876 [5.3%]) and those with ST segment depression in both leads V1 to V3 and leads V4 to V6 (n = 3,373 [20.4%]) on initial electrocardiography. Outcome measures included postinfarction complications (second- or third-degree heart block, congestive heart failure or shock) and 30-day and 1-year mortality.

RESULTS

Patients with precordial ST segment depression had larger infarctions, more postinfarction complications and a higher mortality rate than those without precordial ST segment depression (4.7% vs. 3.2% at 30 days; 5.0% vs. 3.4% at 1 year; both p < 0.001), regardless of whether ST segment depression was noted in leads V1 to V6 or in leads V4 to V6. The magnitude of precordial ST segment depression (sum of leads V1 to V6) added significant independent prognostic information after adjustment for clinical risk factors; the risk of 30-day mortality increased by 36% for every 0.5 mV of precordial ST segment depression.

CONCLUSIONS

Assessment of the magnitude of precordial ST segment depression is useful for acute risk stratification in patients with an inferior myocardial infarction.