A 42-year-old man with no past medical history but a family history of early coronary disease was brought by ambulance to the ED as a code STEMI for shortness of breath and syncope. He said he had no chest pain or pressure, and was feeling fine when he suddenly became weak and dyspneic while lifting weights at the gym. He fainted while supine and still felt light-headed at presentation. He had no recent illness, but did injure his left pectoral muscle about two weeks earlier, also while lifting.
He was tachycardic with a pulse of around 150 bpm, and he was hypotensive and diaphoretic.
The initial differential diagnosis was atrial flutter, pulmonary embolism, acute coronary syndrome, and aortic dissection.
This ECG was taken in the field.
The computer read the ECG as STEMI, sinus tachycardia with occasional PVC, inferoapical ST elevation, anterior infarct (age undetermined), and moderate right axis deviation. Do you agree with the computer?
The computer read was partially correct. This patient also had an intraventricular conduction delay and a posterior fascicular block. STEMI was possible but unlikely due to the inverted T waves in the inferior leads. No baseline ECG was available.
The patient was unstable, and an immediate bedside ultrasound confirmed tamponade. An immediate pericardiocentesis was done with 200 mL of frank blood removed, and the patient stabilized immediately. A pigtail catheter was left in place, and a CT was ordered, which showed no dissection but a small residual pericardial effusion, catheter in the pericardial space.
The hospital ECG was not done until after the procedure and is shown below. The patient was eventually diagnosed with a left ventricular free wall rupture causing tamponade following a transmural MI two weeks earlier (the injured left pec muscle). He survived.
- Always consider tamponade from acute aortic dissection when there is sudden shortness of breath, sweating, and hypotension even if there is no pain. Tachycardia will also usually be present. A stat bedside echo and pericardiocentesis can save lives.
- Other causes of acute tamponade include trauma, ruptured ascending aortic aneurysm, ruptured LV free wall, and coronary artery dissection with rupture.
This post was peer-reviewed by Stephen W. Smith, MD, of Dr. Smith's ECG Blog.
Source: The Emergency Medicine 1-Minute Consult Pocketbook.