Electrocardiographic differentiation between acute pulmonary embolism and non-ST elevation acute coronary syndromes at the bedside.

Background: Clinical picture of acute pulmonary embolism (APE), with wide range of electrocardiographic (ECG) abnormalities can mimic acute coronary syndromes.

Objectives: Assessment of standard 12-lead ECG usefulness in differentiation at the bedside between APE and non-ST elevation acute coronary syndrome (NSTE-ACS).

Methods: Retrospective analysis of 143 patients: 98 consecutive patients (mean age 63.4 +/- 19.4 year, 45 M) with APE and 45 consecutive patients (mean age 72.8 +/- 10.8 year, 44 M) with NSTE-ACS. Standard ECGs recorded on admission were compared in separated groups.

Results: Right bundle branch block (RBBB) and S(1)S(2)S(3) or S(1)Q(3)T(3) pattern were found in similar frequency in both groups (10 [11%] APE patients vs 6 [14%] NSTE-ACS patients, 27 [28%] patients vs 7 [16%] patients, respectively, NS). Negative T waves in leads V(1-3) together with negative T waves in inferior wall leads II, III, aVF (OR 1.3 [1.14-1.68]) significantly indicated APE with a positive predictive value of 85% and specificity of 87%. However, counterclockwise axis rotation (OR 4.57 [2.74-7.61]), ventricular premature beats (OR 2.60 [1.60-4.19]), ST depression in leads V(1-3) (OR 2.25 [1.43-3.56]), and negative T waves in leads V(5-6) (OR 2.08 [1.31-3.29]) significantly predicted NSTE-ACS.

Conclusions: RBBB, S(1)S(2)S(3), or S(1)Q(3)T(3) pattern described as characteristic for APE were not helpful in the differentiation between APE and NSTE-ACS in studied group. Coexistence of negative T waves in precordial leads V(1-3) and inferior wall leads may suggest APE diagnosis.