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 essential for appropriate use of thrombolytic therapy and primary angioplasty. However, 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 (V7-V9) and RV (V4R-V6R) leads to determine their predictive value for hospital life-threatening complications (HLTCs).


RESULTS
This prospective trial of seven Midwestern hospital emergency departments (EDs) had inclusion criteria of age 35 years, chest pain suggestive of ischemia, and coronary care unit (CCU) admission. ECG leads were test positive if STSE was > 0.1 mV. Patients were positive for HLTCs if ED or inpatient hospital course included: ventricular fibrillation or tachycardia, second- or third-degree block, shock, arrest, or death. Univariate and multivariate analyses were performed to test each lead's association with HLTCs. Of 533 patients, 64.7% (345/533) had AMI 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%). V1 (odds = 3.2) and V6R (odds = 3.1) were statistically significant independent predictors.


CONCLUSIONS
Posterior and RV leads did not increase the ECG's overall prognostic value, but in the presence of inferior STSE, were associated with low and high complication rates, respectively. Right and left precordial leads were the best predictors of HTLCs.
Zalenski
R J
RJ
Department of Emergency Medicine and Medicine, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
Rydman
R J
RJ
Sloan
E P
EP
Hahn
K
K
Cooke
D
D
Tucker
J
J
Fligner
D
D
Fagan
J
J
Justis
D
D
Hessions
W
W
Pribble
J M
JM
Shah
S
S
Zwicke
D
D
D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D003325:Coronary Care Units; D003430:Cross-Sectional Studies; D003657:Decision Making; D004562:Electrocardiography / Q000295:instrumentation*; D004566:Electrodes / Q000592:standards; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D005500:Follow-Up Studies; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D015588:Observer Variation; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity