Prognostic value of lead V1 ST elevation during acute inferior myocardial infarction
Cheuk-Kit Wong1, Wanzhen Gao, Ralph A Stewart
1Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
Insights
ST elevation in lead V(1) during acute inferior myocardial infarction indicates higher mortality risk, especially when persistent. This finding aids in identifying high-risk patients for better management.
Area of Science:
- Cardiology
- Electrocardiography
- Myocardial Infarction
Background:
- Lead V(1) ST elevation in acute inferior myocardial infarction (MI) can indicate right ventricular involvement or posterolateral MI.
- The prognostic significance of V(1) ST elevation may depend on concurrent V(3) ST changes.
Purpose of the Study:
- To investigate the prognostic significance of ST elevation in lead V(1) during acute inferior myocardial infarction.
- To determine if V(1) ST elevation predicts 30-day mortality, considering V(3) ST changes.
Main Methods:
- Analysis of 7967 patients from the HERO-2 trial with acute inferior MI.
- Electrocardiographic analysis of V(1) and V(3) ST levels, including baseline and post-fibrinolysis measurements.
- Statistical adjustment for V(3) ST levels, inferolateral ST elevation, and clinical factors to predict 30-day mortality.
Main Results:
- Baseline V(1) ST elevation as a continuous variable was associated with increased 30-day mortality (odds ratio 1.24 after adjustment).
- Each 0.5-mm increase in V(1) ST elevation correlated with a 25% rise in mortality.
- Persistent V(1) ST elevation (≥1 mm) 60 minutes post-fibrinolysis was linked to significantly higher mortality (10.8% vs. 5.5%).
Conclusions:
- ST elevation in lead V(1) is an independent predictor of higher mortality in acute inferior myocardial infarction.
- This ECG finding helps identify high-risk patients requiring closer monitoring and management.
Background:
Lead V(1) directly faces the right ventricle and may exhibit ST elevation during an acute inferior myocardial infarction when the right ventricle is also involved. Leads V(1) and V(3) indirectly face the posterolateral left ventricle, and ST depression ("mirror-image" ST elevation) in V(1) through V(3) may reflect concomitant posterolateral infarction. The prognostic significance of V(1) ST elevation during an acute inferior myocardial infarction may therefore be dependent on V(3) ST changes.
Methods And Results:
In 7967 patients with acute inferior myocardial infarction in the Hirulog and Early Reperfusion or Occlusion-2 (HERO-2) trial, V(1) ST levels were analyzed with adjustment for lead V(3) ST level for predicting 30-day mortality. V(1) ST elevation at baseline, analyzed as a continuous variable, was associated with higher mortality. Unadjusted, each 0.5-mm-step increase in ST level above the isoelectric level was associated with approximately 25% increase in 30-day mortality; this was true whether V(3) ST depression was present or not. The odds ratio for mortality was 1.21 (95% confidence interval, 1.07 to 1.37) after adjustment for inferolateral ST elevation and clinical factors and 1.24 (95% confidence interval, 1.09 to 1.40) if also adjusted for V(3) ST level. In contrast, lead V(1) ST depression was not associated with mortality after adjustment for V(3) ST level. V(1) ST elevation >or=1 mm, analyzed dichotomously in all patients, was associated with higher mortality. The odds ratio was 1.28 (95% confidence interval, 1.01 to 1.61) unadjusted, 1.51 (95% confidence interval, 1.19 to 1.92) adjusted for V(3) ST level, and 1.35 (95% confidence interval, 1.04 to 1.76) adjusted for ECG and clinical factors. Persistence of V(1) ST elevation >or=1 mm 60 minutes after fibrinolysis was associated with higher mortality (10.8% versus 5.5%, P=0.001).
Conclusions:
V(1) ST elevation identifies patients with acute inferior myocardial infarction who are at higher risk.
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