ECG changes in pulmonary embolism

ECG changes in pulmonary embolism

ECG changes in pulmonary embolism: The commonest finding on electrocardiogram in pulmonary embolism is sinus tachycardia. Pulmonary embolism can occur without significant electrocardiographic abnormalities. ECG may show right ventricular ischemia, incomplete right bundle branch block pattern or S1Q3T3 pattern (S waves in lead I, Q waves and T wave inversion in lead III). T wave inversion in leads V1 to V3 may indicate right ventricular dysfunction in pulmonary embolism. T inversion in inferior leads can also occur in pulmonary embolism. Right axis deviation is another important feature of pulmonary embolism, which is also indicated by the S waves in lead I in the S1Q3T3 pattern.

A case of pulmonary embolism with ECG showing S1Q3T3 pattern has been reported by Elaine Boey, Swee-Guan Teo and Kian-Keong Poh [1]. It was a 55 year old lady with recent hemorrhagic stroke who presented with breathlessness of one day duration. She gave history of an episode of syncope while doing physiotherapy. Echocardiography showed right ventricular dilatation and severe right ventricular systolic dysfunction. Computed tomographic pulmonary angiography (CTPA), showed filling defects suggestive of thrombus from main pulmonary trunk to the peripheral arteries.

Reference

1. Elaine Boey, Swee-Guan Teo, Kian-Keong Poh, Electrocardiographic Findings in Pulmonary Embolism. Singapore Med J. 2015 Oct;56(10):533-7.