Background: Patients with acute pulmonary embolism (APE) often have negative T waves (Neg T) in precordial leads at presentation, but this is also found in acute coronary syndrome (ACS) caused by left anterior descending coronary artery (LAD) disease.
Methods and results: Differences in Neg T on admission electrocardiograms were studied between 107 patients with APE and 248 patients with ACS caused by LAD disease. All patients had Neg T in leads V1-4 and were admitted within 7 days from symptom onset. The number of leads with Neg T (4.8±1.8 vs. 5.5±1.7, P<0.001) and maximum magnitude of Neg T (3.4±2.0 vs. 4.7±3.3mm, P<0.001) were lower in APE. The frequency of occurrence of Neg T in each of the 12 leads, and the precordial lead with the greatest Neg T (peak Neg T) differed between APE and ACS (all P<0.05, respectively). APE was strongly associated with the presence of Neg T in both leads III and V1 and peak Neg T in leads V1-2. The combination of these 2 findings identified APE with 98% sensitivity, 92% specificity, and 94% predictive accuracy, which represented the highest diagnostic accuracy.
Conclusions: Among patients with APE and ACS who have precordial Neg T, the presence of Neg T in leads III and V1 and/or peak Neg T in leads V1-2 simply but accurately differentiates APE from ACS.