Electrocardiographic predictors of ventricular fibrillation in ST-segment elevation acute myocardial infarction

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Abstract Introduction Ventricular fibrillation (VF) during ST-segment elevation myocardial infarction (STEMI) is a critical emergency that requires immediate action to recover sinus rhythm and prevent sudden death. The surface electrocardiogram (ECG) is an essential diagnostic tool performed during STEMI. Our objective was to identify markers on the ECG that might be useful as potential predictors of peri-infarct VF. Methods Data was obtained prospectively from consecutive patients with a STEMI diagnosis admitted to the Cardiology Acute Care Unit at a tertiary hospital from July-2019 to May-2020. In all cases, primary angioplasty was performed. Clinical and laboratory data and in-hospital complications were collected. Surface ECG parameters were evaluated at the time of diagnosis. Results Of a total of 93 patients included, 11 patients had peri-infarct VF (11.8%). No differences in age, sex or cardiovascular risk factors between groups were found. The ECG at admission showed notable differences: the degree of maximum elevation of the ST segment in mm (STmax) and the sum of such elevation (STsum) in all leads were significantly higher in the VF group (Table). A receiver operating characteristics analysis was performed in order to evaluate the diagnostic capacity of STmax for VF (Figure). A cut off of 4 mm (4mV) in STmax demonstrated the highest sensitivity and specificity for predicting VF. Patients with ST elevation >4mm in any lead had a 16 times greater probability of developing peri-infarct VF (OR 16.4, 95% CI 1.98–136.4; p=0.01). After adjusting for age, STsum also showed a significant association with peri-infarct VF. An STsum of >12mm resulted in a 4 times greater risk of VF. Conclusions The surface ECG remains an essential tool in the evaluation of patients with STEMI. The maximum ST elevation and the sum of the ST elevation demonstrates a strong association with the development of peri-infarct VF. A ST elevation >4mm in any lead is associated with a 16 times higher risk of developing VF. Funding Acknowledgement Type of funding sources: None. Table 1. Baseline demographics, electrocardiographic (ECG) and laboratory data in patients with and without ventricular fibrillation. CKD: chronic kidney disease. STmax: maximum elevation of the ST segment in the ECG measured in millivolts (mV). STsum: sum of all ST elevation on the 12 lead ECG. LVEF: left ventricular ejection fraction.Figure 1. Receiver operating characteristics (ROC) curve analysis to evaluate the diagnostic capacity of maximum ST elevation for the development of ventricular fibrillation in patients with infarction.