[banbulance]

Can comeone explain why a right sided coronary blokage may be worse than a left?

I don't get it

[Dinith88]

Originally Posted by banbulance

Can comeone explain why a right sided coronary blokage may be worse than a left?

I don't get it

Whoever told you that is wrong.

Where they're coming from (i beleive) is that a 'right sided' (meaning 'right coronary artery' or 'inferior' MI) can (~40-50% of the time) involve the right ventricle. These patients are sensitive to meds (esp. nitro) and can be more likely to become hypotensive...(requiring fluid bolus, etc.). Can make for a difficult patient to treat w/meds.

But it's all relative really.

Ask this person if a 'small' rt sided mi is worse than a 'massive' lt sided MI. I'd be very intetrested in the answer...

But again...i think they're talking about the potential hemodynamic compromise that can accompany inferior MI (~40% of the time...)

[cardiodiot]

RCA supplies SAN.

[Dinith88]

Originally Posted by cardiodiot

RCA supplies SAN.

This is a good point. However, the RCA doesnt always feed the SA-node...so to make this blanket statement is a bit misleading. Also, the chances of an RCA/inferior MI knocking out the SA-node are small(real...but small). In contrast, the potential for RV involvement is much higher (~40-50%)...and i beleive this is from where the OP's question stems...because these RV MI's are harder to treat with 'standard' meds (ie nitro).
(...And the potential for blocks and lethal arrhythmias can just as easily stem from the left coronary system...)

Again, i think the question is loaded and that it's all relative.
Is the vessel dominant? Is the occlusion proximal? Distal? Any collateral circulation? etc.

Whoever thinks an RCA lesion is worse than a left-main lesion (for example)(because you 'could potentially knock-out the SA-node') would be hard pressed to convince me. Forget the SA node, if you shut down the Left main the patient's done.

I think the OP's teacher (or text-book) could have better phrased the question as "...what are some potential complications of right coronary artery MI's..."
Sure..they can be very bad and lethal(duh)...but so can left coronary occlusions(ummm duh again)...for various reasons.

[Dinith88]

Originally Posted by Dinith88

This is a good point. However, the RCA doesnt always feed the SA-node...

Should've mentioned (didnt because i wanted to get my numbers right first) that in almost half of patients the SA-node actually gets its blood supply from the CIrcumflex artery...which is, of-course, a branch of the left coronary system...

[SEOBowhntr]

Originally Posted by Dinith88

Should've mentioned (didnt because i wanted to get my numbers right first) that in almost half of patients the SA-node actually gets its blood supply from the CIrcumflex artery...which is, of-course, a branch of the left coronary system...

Since when??? I think you may be getting your coronary arteries confused.

Right sided MI's are sometimes worse than left, esp if there is Right Ventricle involvement, because then you play a game of drown the patient, to maintain flow into the left side of the heart, then you have to VERY CAUTIOUSLY diurese them. Right sided MI's have a higher mortality, and really are about as bad as you can get if you are the nurse trying to take care of them. The RV infarct patient gets his/her perfusion from the central venous pressure if the RV is severely infarcted. I cared for a gentleman who closed off his RCA graft shortly after CABG surgery, and his CVP read 25mm Hg at one point prior to sending him to the Cath Lab for a stent and balloon pump. The patient had bonafide BP's in the 60/30 range, and was pretty moderately 3rd spaced only 48hours post-op.

Interest in recognizing right ventricular infarction noninvasively has grown because of the therapeutic implications of distinguishing patients with right ventricular dysfunction from those with the more usual clinical presentation of left ventricular dysfunction. Patients with right ventricular infarctions associated with inferior infarctions have much higher rates of significant hypotension, bradycardia requiring pacing support, and in-hospital mortality than isolated inferior infarctions (Chockalingam, 2005).

From this link: http://www.emedicine.com/med/topic2039.htm

[Dinith88]

.....

[Dinith88]

Originally Posted by SEOBowhntr

Since when??? I think you may be getting your coronary arteries confused.

Right sided MI's are sometimes worse than left, esp if there is Right Ventricle involvement, because then you play a game of drown the patient, to maintain flow into the left side of the heart, then you have to VERY CAUTIOUSLY diurese them. .

Only if the patient is in heart failure/pulmonary edema..otherwise diuresing someone w/MI isnt part of the recipe...

I think a bigger drug to watch is nitro...because you (ideally) will be giving it to most MI patients who can tolerate it...