The Relationship of ST Segment Changes in Lead aVR with Outcomes after Myocardial Infarction; a Cross Sectional Study
Mohammad Reza Beyranvand1, Mohammad Assadpour Piranfar1, Mohammadreza Mobini2
1Department of Cardiology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Insights
ST segment changes in lead aVR, often overlooked in electrocardiography (ECG), are prevalent in myocardial infarction (MI) patients. ST elevation in lead aVR significantly predicts an eightfold increase in in-hospital mortality risk.
Area of Science:
- Cardiology
- Electrocardiography
- Medical Diagnostics
Background:
- The electrocardiogram (ECG) typically focuses on 11 leads, often neglecting lead aVR.
- Lead aVR provides a unique mirror image perspective of cardiac electrical activity.
- Understanding ST segment changes in lead aVR is crucial for comprehensive cardiac assessment.
Purpose of the Study:
- To determine the prevalence of ST segment changes in lead aVR among patients with myocardial infarction (MI).
- To investigate the association between ST segment changes in lead aVR and in-hospital mortality.
- To explore the relationship between lead aVR ST changes and infarct characteristics.
Main Methods:
- Retrospective cross-sectional study of 288 patients diagnosed with MI.
- Analysis of ECGs for ST segment changes in lead aVR.
- Correlation of lead aVR findings with in-hospital mortality, vessel involvement, infarct location, and ejection fraction.
Main Results:
- ST segment changes in lead aVR were observed in 58.3% of MI patients.
- No significant association was found between lead aVR ST changes and infarct location, number of involved vessels, or ejection fraction.
- ST elevation ≥ 1 mV in lead aVR was significantly linked to an increased risk of in-hospital mortality (Odds Ratio = 7.72).
Conclusions:
- ST segment changes in lead aVR are common in MI patients.
- Lead aVR ST elevation is a strong predictor of in-hospital mortality.
- Lead aVR analysis offers valuable prognostic information in acute MI.
Introduction:
Among the 12 leads studied in electrocardiography (ECG), lead aVR can be considered as the most forgotten part of it since no attention is paid to it as the mirror image of other leads. Therefore, the present study has been designed with the aim of evaluating the prevalence of ST segment changes in lead aVR and its relationship with the outcome of these patients.
Methods:
In this retrospective cross sectional study medical profiles of patients who had presented to emergency department with the final diagnosis of myocardial infarction (MI) in a 4-year period were evaluated regarding changes of ST segment in lead aVR and its relationship with in-hospital mortality, the number of vessels involved, infarct location and cardiac ejection fraction.
Results:
288 patients with the mean age of 59.00 ± 13.14 (18 - 91) were evaluated (79.2% male). 168 (58.3%) patients had the mentioned changes (79.2% male). There was no significant relationship between presence of ST changes in lead aVR with infarct location (p = 0.976), number of vessels involved (p = 0.269) and ejection fraction on admission (p = 0.801). However, ST elevation ≥ 1 mv in lead aVR had a significant relationship with mortality (Odds = 7.72, 95% CI: 3.07 - 19.42, p < 0.001). Sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios of ST elevation ≥ 1 for prediction of in-hospital mortality were 41.66 (95% CI: 22.79 - 63.05), 91.53 (95% CI: 87.29 - 94.50), 31.25 (95% CI: 16.74 - 50.13), 94.44 (95% CI: 90.65 - 96.81), 0.45 (95% CI: 0.25 - 0.79), and 0.05 (95% CI: 0.03 - 0.09), respectively.
Conclusion:
Based on the results of the present study, the prevalence of ST segment changes in lead aVR was estimated to be 58.3%. There was no significant relationship between these changes and the number of vessels involved in angiography, infarct location and cardiac ejection fraction. However, presence of ST elevation ≥ 1 in lead aVR was associated with 8 times increase in in-hospital mortality risk.
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