[HSF] Postop cardiac syncope

[Tea Acuff]

I would be interested in suggestions for a recent case, both to see how people think and perhaps to find a novel answer(s).

The case.

A seventy four year old male presented about 2-3 week ago with ST elevation inferior MI, which was aborted with a DES to the main RCA. This helped significantly since he had only a diagonal and high OM patent on the left with poor filling of occluded LAD and PL with moderate left main. He also had a 95% mid PDA and probably 70% proximal PDA. LVgram not done then. Very dominate RCA. He was sent home.
 
Patient readmitted at two weeks after stopping Plavix for 4 days. TEE periop minimal inf LV dysfunction and mild MR. Had uneventful OPCAB with Lima to LAD, but even proximal LAD was 1mm or less as was PL of circ. RSV to Diag and RSV to OM, large PL of RCA and to endartectomized mid PDA. Extubed at or shortly after arrival to ICU. Bleeding 200-300 ccs first shift; no Swan Ganz. Was up in chair at 6-8 hours post op at shift change on moderate levo for BP (presumed vasoplagia by good ICU nurse) when his monitor went off and he was slumped over in chair. No meds and pushed on chest with resumed BP and NSR. CRX, Hct, K, ABG okay. I came in (about 40 minutes later), he had had 3rd degree HB with out ventricular response and had had another episode without syncope. I weaned levo and gave some colloid which stabilized. Since he had no pacer wires I got the cardiologist (probably could have found a pacing SG and done it myself) and put in a VVI pacer the next morning despite NSR. No
 evidence of periop MI.

How should I think about preventing any of this in the future or should I just say that everything worked properly? (Patient is afterall okay.)
Does this happen at home when we think that they acutely occluded their grafts?
Has anyone seen sudden and brief 3rd degree HB with otherwise NSR without clear ischemia? I don't remember ever seeing it exactly like this.
What really happened? Or better yet what would you do to prove what you thought happened?
Would anyone do anything different after his first syncope/arrest?

tea