Cardiac Arrest, widespread ST depression, but NOT due to ACS

Cardiac Arrest, widespread ST depression, but NOT due to ACS

by Steve Smith

This young male had ventricular fibrillation during a triathlon. He was resuscitated with chest compressions and defibrillation and 1 mg of epinephrine. On his bib it stated that he had a congenital heart disorder. He arrived in the emergency department hemodynamically stable. His initial ECG is shown here.
There is widespread ST depression. However, note that wherever there is ST depression, it is associated with a very high voltage R-wave. There is profound LVH. Such widespread ST depression maybe secondary to LVH, or due to ischemia, or to both. When there is widespread ST depression do to acute coronary syndrome, it is usually due to three-vessel disease or left main disease. This would be highly unusual in a young athlete. Therefore, one must conclude that the ST depression is either do to LVH or to demand ischemia, or both.

A bedside echo performed by the emergency physician showed no wall motion abnormality and confirmed LVH. A repeat ECG shown.

Now, there is less ST depression. The troponin returned positive, and the maximum troponin was 3.8 ng/ml. Thus, the ST depression was at least in part due to ischemia. This confirms a "Type II" myocardial infarction; that is to say, it is not due to ACS but rather to demand ischemia.
The next day, and angiogram showed normal coronary arteries. An echocardiogram confirmed aortic stenosis with a large pressure gradient. The stress of the triathlon cause demand ischemia and ventricular fibrillation