Acute pulmonary embolism (PE)  is a common condition that can be both severe and difficult to diagnose. Half of all acute PE cases are diagnosed in the emergency department, and acute PE follows acute coronary syndrome as the second most common cause of sudden unexpected death in outpatients. Also, right ventricular dysfunction is a consequence of massive/submassive acute pulmonary embolism and correlates with a poor prognosis and high mortality rate. Although an ECG lacks both sensitivity and specificity for acute PE, there are some clues that can help in determining the size of an acute PE.

What are some of the common ECG changes seen with massive acute PE? 1

ECG ChangesMassive PE (%)Non-Massive PE (%)
Anterior Ischemic Pattern8519
Sinus Tachycardia360
Low Voltage3636
Pulmonary P Waves70

Study methodology: 80 patients enrolled, prospective study


Anterior ischemic pattern (inverted T waves) on ECG was the most frequently observed ECG abnormality in patients with massive acute PE.

  • Had the best sensitivity (85%), specificity (81%), PPV (93%), and NPV (65%) for massive acute PE
  • Correlated highly with a Miller index of >50% (90%) and mean pulmonary artery pressure (PAP) >30 mmHg (81%)

What are some of the common ECG changes seen with right ventricular dysfunction due to acute PE? 2–4

ECG ChangesRV Dysfunction (%)Without RV Dysfunction (%)
T-Wave Inversion in Leads V1 – V3755 – 12
RBBB30 – 46.43 – 17
Qr in Lead V1313
S1Q3T325 – 355.5 – 10
Normal ECG849

Study methodology: 204 patients enrolled with acute PE


T-wave inversion in leads V1 – V3 was the most prevalent finding on ECG with right ventricular dysfunction due to acute PE.

  • Sensitivity of 75%
  • Specificity of 88–95%
  • NPV of 86–95.5%
  • PPV of 73.1-78%


In general, the ECG is not very sensitive or specific for acute PE, but T-wave inversions in leads V1 – V3 seem to be the most common ECG finding in massive/submassive acute PE with a diagnostic accuracy of close to 80%.

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Kucher N, Walpoth N, Wustmann K, Noveanu M, Gertsch M. QR in V1–an ECG sign associated with right ventricular strain and adverse clinical outcome in pulmonary embolism. Eur Heart J. 2003;24(12):1113-1119. [PubMed]
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Kim S, Park D, Choi H, et al. The best predictor for right ventricular dysfunction in acute pulmonary embolism: comparison between electrocardiography and biomarkers. Korean Circ J. 2009;39(9):378-381. [PubMed]
Salim Rezaie, MD

Salim Rezaie, MD

ALiEM Associate Editor Clinical Assistant Professor of EM and IM University of Texas Health Science Center at San Antonio Founder, Editor, Author of R.E.B.E.L. EM and REBEL Reviews