Abstract 14643: Clinical and Electrocardiographic Characteristics are Insensitive Indicators of Acute Myocardial Infarction in Patients who Present with Chest Pain and Left Bundle Branch Block or Paced Rhythm
BACKGROUND Patients who present to the emergency department (ED) with chest pain and left bundle branch block (LBBB) or paced rhythm are a clinical dilemma. We aim to identify clinical and electrocardiographic characteristics that can predict acute myocardial infarction (AMI).
METHODS Patients who presented to Henry Ford Hospital ED (2005-2009) with chest pain and LBBB, or paced rhythm, in the initial EKG were retrospectively included. We studied the presence of clinical risk factors (history of coronary artery disease, hypertension, diabetes, kidney disease, stroke, hyperlipidemia, peripheral vascular disease, and heart failure; vital signs and chest pain duration), and Sgarbossa criteria on the initial EKG. These risk factors were compared between the patients with and without AMI. Chi-square test, t-test, analysis of variance and logistic regression were used for the analysis.
RESULTS A total of 177 individuals were included. Of these, 102(57.6%) had old LBBB, 58(32.7%) had new LBBB, and 17(9.6%) had a paced rhythm. AMI occurred in 27 patients (15.2%).The median age was 67.3 ±14 years and the median ejection fraction was 39.4±17%. New LBBB was associated with AMI (p=0.02) in the unadjusted analysis but not in the multivariate analysis. The presence of any Sgarbossa criteria on EKG (OR 13.1, 95% CI 3.1-55.3; p<0.001) and history of peripheral vascular disease (OR 21.9, 95%CI 4.1-116; p<0.001) were associated with AMI in the multivariate analysis. The presence of any Sgarbossa criteria had a specificity of 96%, but a sensitivity of 25.9% for AMI (Table 1).
CONCLUSIONS Most patients who presented with chest pain and LBBB did not have AMI. Clinical characteristics are insensitive parameters to evaluate presence of AMI in this population. The presence of any Sgarbossa criteria in the presenting electrocardiogram was very specific but not sensitive. More research is needed to better stratify the risk of AMI in this population.
- © 2012 by American Heart Association, Inc.