ST depression after cardiac arrest is frequently not due to ACS
Posted Jun 08 2012 10:05am
A 22 yo male had a cardiac arrest with ventricular fibrillation recorded. He was resuscitated. He was comatose. Here is his initial ECG:
There is widespread ST depression, with ST elevation in aVR. There are also lateral Q-waves.
Is this ACS with 3-vessel disease or left main stenosis? No, and one should not make such an assumption. The initial ECG after a cardiac arrest frequently shows ischemic ST depression which resolves on subsequent ECGs. So we waited and recorded a second ECG 27 minutes later
The ST depression is resolved. The Q-waves persist.
The patient had myocarditis and no coronary disease. He underwent therapeutic hypothermia and fully recovered.
A young man presented after resuscitation from asystolic cardiac arrest. In spite of immediate bystander CPR, he had no brain function on arrival.
There is ST depression in V2-V6. Is this ACS?
The total absence of brain function in spite of immediate CPR suggested a CNS etiology of arrest. CT of the brain revealed aneurysmal subarachnoid hemorrhage. The patient went on to brain death.
Cardiac arrest was likely due to massive catecholamine surge and stress cardiomyopathy.
Do all cardiac arrest patients need emergent angiography and PCI?
Finally, many or most patients with cardiac arrest and positive troponins have "Acute MI" by the new 2007 definition, but do not have type I AMI due to ACS.
Therefore, don't always think "STEMI", or even "cath lab," when you take care of a patient with resuscitated cardiac arrest, and even if they have ST depression; the cath lab need only be emergently activated for definite STEMI-equivalent, persistent ischemia, electrical instability, or hemodynamic instability.
I know there are differing opinions on this, and no randomized trials. I would be interested to hear your evidence-based feedback on this.