Heat Dilates Coronary Arteries?

[Ken289]

Anyone have any data (or speculation) about whether hot compresses (hot towels, water bottle, etc) on the chest would lead to coronary artery dilation? I have been trying this with mild angina after stent and it seems to help....mild arm/finger pain goes away. Already taking slow release nitrates (isosorbide) so this was a experiment to see if the heat provided additional dilation. At a minimum, it feels good.

I can not find any mention in my searches. Any comments?

[Lenin]

Ken,
I find when I feel warm my BP is lower than when I am cold. I KNOW that when the body is trying to disperse excess heat, that the major process is the dilation of the skin's artery system to allow hot blood to flood to the surface effecting cooling.
So, yes, it seems logical that warm compresses would dilate your arteries. To what extent it dilates your CORONARY arteries, I don't know.

Now for the opposite, I know that any exertion in a overly long stay in a very hot steam and/or sauna can BRING ON angina pain ! But I atttribute that to dehydration and OVERHEATING in an environment where it is impossible for the body to disperse heat. (120 degree F. steamroom and 195 degree F. sauna.) Steam has a more dangerous effect than the sauna because in steam there is NO cooling method left for the body!

I guess you could call that the yin and the yang of heat application !

[Ken289]

Lenin: thanks for commenting; I've gotten no comments here or one other place, surprisingly. Your sauna example, while true in and of itself, is not applicable in the example I pose, IMO.

Heat transfer thru tissue should say that the localized temperature of nearby structures, ie, coronary arteries, should rise and hence relax and probably dilate. I also suspect the dilation is a function of the temperature so that as long as you keep the heat there, you maintain some relaxed and expanded diameter.

I became interested in this while suffering (a good word) the headaches of isosorbide (imdur) slow release nitro and thinking that an additional dose of sublingual nitro could not expand the arteries much more. (A conversation with the local pharmacist however told me that additional expansion was possible as long as nitro concentrations rose.) In any case, with the headache at maximum (ug), I tried the hot towel thing and it seemed to help. Maybe a placebo effect for sure.

One also could speculate what additional blood flow into the heart muscle itself might occur if the temperature of the organ is raised. Does it have the same temperature regulating effects as the skin like you mention?

All sorts of interesting theories.

[Lenin]

Ken,

I really doubt that anything you could do on the surface of your chest could change the temperature of your heart by even a tenth of a degree...well, maybe flaming gasoline. I think the effect you experience might be from an overall drop in BP. After all, the hardest work a heart does is to maintain that pressure head through many miles of vessels.
Try the same hot compresses on your legs and see if the effect on your exertional angina is the same...or even sit in a hot bath.

Trouble is, angina is fleeting with time. Doing NOTHING after exertion will make it stop so putting on a compress, getting into a bath, working a crossword puzzle, eating a prune, or even watching TV might seem to have the same effect when actually it's recovery time away from exertion that is doing the trick.

Refresh my memory; are you on beta-blockade?

[Ken289]

Lenin: no, not on any beta blockers. Plus, my angina (if it is really angina) occurs at rest not at exertion. I have been reading about arterial spasm and collapse at the stent site (at the leading edge of the stent). This might be what is going on. When I was discharged, the doc mentioned that he was prescribing the imdur (isosorbide--extended release nitro) to combat possible spasm. The little I have found seems to suggest that the spasm constricts the artery just in front of the stent and that it does not rebound back fully. Again, the literature is murky and not a lot of it. So it has been in the context of mild angina pains (really no chest pain, just pain in my inside edge of my left hand) while having severe headaches from the slow release nitro and not wanting to take sublingual nitro on top of that--that is why I was trying the hot compresses. A cardiologist friend on another site said about the same thing you did---hard to raise the core temperature of the heart externally.

Sigh....