ECG Case 070

Elderly patient presenting with sudden onset of chest pain and shortness of breath. Hypoxic (SaO2 82% RA) and hypotensive (80/50). Describe and interpret his ECG

TOP 100 ECG QUIZ LITFL 070

Describe and interpret this ECG

ECG ANSWER and INTERPRETATION

There are multiple features suggestive of right ventricular hypertrophy or RV strain:

Given the clinical history, the most likely scenario is acute right heart strain due to massive pulmonary embolism.

A similar ECG pattern may also be seen with chronic cor pulmonale, pulmonary hypertension or RV hypertrophy (e.g. due to congenital heart disease).


CLINICAL PEARLS

ECG changes in pulmonary embolism include:

  • Sinus tachycardia – the most common abnormality; seen in 44% of patients.
  • Complete or incomplete RBBB associated with increased mortality; seen in 18% of patients.
  • Right ventricular strain pattern –  T wave inversions in the right precordial leads (V1-4) ± the inferior leads (II, III, aVF). This pattern is seen in up to 34% of patients and is associated with high pulmonary artery pressures.
  • Right axis deviation – seen in 16% of patients. Extreme right axis deviation may occur, with axis between zero and -90 degrees, giving the appearance of left axis deviation (“pseudo left axis”).
  • Dominant R wave in V1 – a manifestation of acute right ventricular dilatation.
  • Right atrial enlargement (P pulmonale) – peaked P wave in lead II > 2.5 mm in height. Seen in 9% of patients.
  • SI QIII TIII  pattern – deep S wave in lead I, Q wave in III, inverted T wave in III. This “classic” finding is neither sensitive nor specific for pulmonary embolism; found in only 20% of patients with PE.
  • Clockwise rotation – shift of the R/S transition point towards V6 with a persistent S wave in V6 (“pulmonary disease pattern”), implying rotation of the heart due to right ventricular dilatation.
  • Atrial tachyarrhythmias – AF, flutter, atrial tachycardia. Seen in 8% of patients.
  • Non-specific ST segment and T wave changes, including ST elevation and depression. Reported in up to 50% of patients with PE.

Simultaneous T wave inversions in the inferior (II, III, aVF) and right precordial leads (V1-4) is the most specific finding in favour of PE. 


TOP 100 ECG SERIES


Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education | ECG Library |

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