Tachycardia and an occluded RCA

[Kerrigan 06]

I'm a 6-months-new nurse and I work in a CVICU. Last night, I was taking report on a post-cath patient. He'd had a CABG 8 years ago, and his first cath showed all of his vein grafts to be heavily occluded. Some were repaired at that time - this was last week. Then yesterday, he went back to the cath lab for repair of the saphenous vein graft to the OM. The reporting nurse told me that the patient's native RCA still required repair - due to a lack of much useful information on the chart and the cardiologist's absence thus far in the unit, we didn't know if further repair was planned.

When the nurse reviewed systems, she told me that he was in a sinus bradycardia with a rate in the 40s-50s. When I looked alarmed at the mention of sinus in the 40s, she told me "Pray that he stays there! With that RCA occlusion, if he gets tachycardic, he'll die."

I didn't take the opportunity to clarify, but I kept wondering: Why? What is it about the RCA with occlusion that dooms a tachycardic patient to death, moreso than any other coronary artery such as the LAD?

I have a LOT to learn. Any insight?

[meandragonbrett]

If they have an acclusion...in any of the arteries, tachycardia is going to rapidly increase myocardial oxygen demands and will result in myocaridal ischemia in the area of occlusion and beyond the occlusion. The slower the rate, the less the myocardial oxygen demand will be. we often use esmolol in this situation for rate control.

[loriann, BSN, RN]

If they have an acclusion...in any of the arteries, tachycardia is going to rapidly increase myocardial oxygen demands and will result in myocaridal ischemia in the area of occlusion and beyond the occlusion. The slower the rate, the less the myocardial oxygen demand will be. we often use esmolol in this situation for rate control.

Thanks for this explanation. I had a similar situation to the OP's today. Now I understand.

[txdude35]

Just make sure the bradycardia is asymptomatic. If they get _too_ beta-blocked you've bought yourself a whole new set of problems. Watch your urine output, changes in mental status, or a drop in bp. Never hurts to have a little atropine handy, just in case.

[cardiac.cure03]

FYI: I DO know that your RCA feeds your AV node, so w/ an occluded RCA, you wanna watch for bradycardia and any blocks.

P.S. I have TONS to learn too!