Atrial fibrillation with rapid ventricular response with ECG injury pattern
Posted Aug 14 2009 6:48pm
This elderly woman presented hypotensive, pale, and tachycardic. She was in atrial fibrillation with a very fast ventricular response. Suspected GI bleed was confirmed with blood on rectal exam. The first ECG was recorded, showing a fib with RVR and infero-posterior injury (STEMI).
The patient was given blood and fluids until bedside ultrasound showed good central venous pressure (distended inferior vena cava), but she remained hypotensive, tachycardic, and the ST elevation did not resolve. Thus, she was electrically cardioverted at 200J biphasic, but this was unsuccessful x 3. Amiodarone 300 mg IV was infused with no improvement, and a subsequent cardioversion was again unsuccessful. She was loaded with 500 mcg/kg of esmolol and started on a 50 mcg/kg/min drip, after which a fifth cardioversion was successful, and resulted in the second ECG shown. The rhythm is sinus, rate normal, and all ST elevation and depression is now resolved.
Troponin peaked at 19, and there was a subsequent inferior wall motion abnormality. A stress sestamibi showed no inducible ischemia, so no cath was done. Whether there was thrombus in the infarct-related artery, or whether this was only demand ischemia is uncertain. Nevertheless, it is wise to convert atrial fibrillation with a rapid response when the patient is unstable; any injury pattern on the ECG constitutes instability.