The impact of electrocardiographic left ventricular hypertrophy and bundle branch block on the triage and outcome of ED patients with a suspected acute coronary syndrome: a multicenter study.

We studied the impact on triage and outcome of the presence of left ventricular hypertrophy (LVH) and left/right bundle branch block (LBBB/RBBB) on the initial ED electrocardiogram (ECG) for patients with symptoms suggestive of an acute coronary syndrome (ACS). Secondary analysis of data from a prospective clinical trial of patients with chest pain or other symptoms suggesting ACS in six U.S. hospitals comparing patient demographics, clinical variables, and outcomes was used. Of 5,324 study patients, 3% had ECG-LVH, 3% had LBBB, 3% had RBBB, and 43% had ischemic ST segment or T wave abnormalities. Compared with patients without ST segment or T wave abnormalities, patients with ECG-LVH or BBB were older and were more likely to have a chief complaint of shortness of breath or a history of cardiac or related diseases. Patients with ECG-LVH or BBB had more diagnoses of congestive heart failure (CHF) and ACS compared with patients without these ECG abnormalities and were just as likely to have ACS as their diagnosis compared with patients with ischemic ST segment or T wave abnormalities. Having ECG-LVH or BBB did not alter the true-positive rate for ACS but increased the false-positive rate by almost 50%. Patients with ECG-LVH had approximately 3.5 times the 30-day mortality rate as those without these ECG abnormalities. It appears that for patients with symptoms suggestive of ACS, the presence of ECG-LVH or BBB did not alter the ability of ED clinicians to identify patients with ACS but was associated with a 50% higher false-positive admission rate compared with similar patients without these ECG abnormalities. With a short-term mortality rate 3.5 times that for patients without ECG-LVH, selected patients with ECG-LVH and symptoms suggesting ACS might benefit from hospitalization for further evaluation.