ECG changes in pulmonary embolus (PE)
Last reviewed 01/2018
In a patient who has suffered a pulmonary embolus there may be transient non-specific changes in the patient's ECG:
- often no changes are seen on the ECG
- classical changes are S1, Q3, T3
The detailed changes are as follows:
- tall R waves in V1
- P pulmonale (peaked P waves) best seen in the inferior leads
- there may be right axis deviation and clockwise rotation
- atrial arrhythmias may occur
- there may be T wave inversion in the leads V1, V2, V3
- possible right bundle branch block
- there may be a shift of transition point to the left, so that the R wave equals the S wave in V5 or V6 rather than V3 or V4
- in this condition there is often a Q wave in lead 3, resembling an inferior infarction
- right ventricular strain is very occasionally seen, causing an S wave in
lead I, Q wave and inverted T wave in lead III
- right ventricular strain pattern on ECG is associated with adverse short-term outcome and adds incremental prognostic value to echocardiographic evidence of right ventricular dysfunction in patients with acute pulmonary embolism and normal blood pressure (1)
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