- The ECG shows tachycardia (rate just >100 bpm) with a wide QRS complex. A right bundle branch block pattern is present.
- There is a large upright QRS in AVR suggesting right axis deviation but examination of the other limb leads suggests axis is deviated to the left at near -90 degrees.
- There are no definite P waves, making the rhythm indeterminate.
- Is there ST segment elevation somewhere in V1-V4? Hard to say definitely yes or no, but there is no suggestion of reciprocal changes in the inferior leads.
Taken together, the patient’s clinical presentation and an ECG suggestive of acute right heart strain (RBBB, axis shift) indicates the possibility of pulmonary embolus. The presentation is also consistent with large vessel acute coronary occlusion (STEMI). In a hemodynamically viable patient, emergency transfer to the cath lab would be a reasonable course. However, with a patient who is intermittently in cardiac arrest, one could consider treatment with thrombolytics, which would address both acute coronary occlusion and PE.
Oh, yes, the patient could also have a dissection, but with this presentation, mortality would be virtually 100%.
Post-mortem examination by the Wayne County Medical Examiner confirmed that the patient expired from massive bilateral pulmonary embolism.
As far as the ECG is concerned, it is trivial, but nevertheless correct, that sinus tachycardia is the most common ECG abnormality associated with pulmonary embolism. More significant and clinically helpful is that right bundle branch block (62%) and axis shifts are commonly present in patients with massive pulmonary embolism. In patients with these findings and a suggestive clinical presentation, pulmonary embolism is a likely diagnosis. In critical situations, treatment with thrombolytics should be considered before a diagnosis can be confirmed by testing.
Surawicz B, Knilans TK: Chou’s Electrocardiography in Clinical Practice, 5th ed., 2001.
Tracings is a learning module involving actual cases of patients and their ECGs that present to the Emergency Department. Topics chosesn are dervied from the EM Model for Resident Education.