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 S₁S₂S₃ or S₁Q₃T₃ 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, S₁S₂S₃, or S₁Q₃T₃ 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. Ann Noninvasive Electrocardiol 2010;15(2):145–150