ST segment elevation and the prediction of hospital life-threatening complications - The role of right ventricular and posterior leads

Accurate prognosis in suspected acute myocardial infarction (AMI) is essent ial for appropriate use of thrombolytic therapy and primary angioplasty. Ho wever, previous models may be limited because the 12-lead electrocardiogram (ECG) does not examine the right ventricular (RV) and posterior myocardium . We evaluated ST segment elevation (STSE) in posterior (V-7-V-9) and RV (V -4R-V-6R) leads to determine their predictive value for hospital life-threa tening complications (HLTCs). Method and Results: This prospective trial of seven Midwestern hospital emergency departments (EDs) had inclusion criter ia of age 35 years, chest pain suggestive of ischemia, and coronary care un it (CCU) admission. ECG leads were test positive if STSE was > 0.1 mV. Pati ents were positive for HLTCs if ED or inpatient hospital course included: v entricular fibrillation or tachycardia, second- or third-degree block, shoc k, arrest, or death. Univariate and multivariate analyses were performed to test each lead's association with HLTCs. Of 573 patients, 64.7% (345/533) had AMT and 15.8% (85/533) had HLTCs. The sensitivity of 18 leads for HLTCS was increased by 5.8%, but specificity decreased by 8.2%. ECG subgroups by STSE were associated with the following HLTC rates: inferior/+RV (32.4%); anterior (29.5%), lateral (23.1%), inferior RV (17.9%), and posterior (16.2 %). V-1 (odds = 3.2) and V-6R (odds = 3.1) were statistically significant i ndependent predictors. Conclusion: Posterior and RV leads did not increase the ECG's overall prognostic value, but in the presence of inferior STSE, w ere associated with low and high complication rates, respectively. Right an d left precordial leads were the best predictors of HTLCs.