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Richard N. Fogoros, M.D.

Heat Waves and Heart Disease

By June 3, 2013

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A prolonged heat wave can be tough on anyone, but if you have heart disease you need to be especially careful when it's hot. This is because the high environmental temperatures can put excess stress on your heart, and also because it is often easier for people with heart disease to develop potentially dangerous heat illness.

In a hot environment, the body attempts to dissipate excess heat (mainly by sweating, and by radiating heat from the skin) to maintain a reasonably normal body temperature. The need to dissipate heat places added stress on your cardiovascular system, and this stress may cause the symptoms of your underlying heart disease to worsen. For instance, a person with coronary artery disease may develop angina; or a person with heart failure may have more shortness of breath.

In extreme heat, the body's attempts to dissipate heat can become overwhelmed, and if this happens the body's temperature begins to rise. The increase in body temperature, along with the dehydration and electrolyte imbalances that most often accompany it, produces heat illness.

Heat illness is a continuum of disorders ranging from heat rash, to heat cramps (muscle cramps), to heat exhaustion (cramps, weakness, dizziness, nausea and vomiting, headache), to heat stroke (body temperature of 106 degrees F. or higher, plus neurological symptoms such as seizures, disorientation, or coma). Heat stroke can be fatal.

Unfortunately, the drugs that are often used in treating heart disease can make it more difficult for your body to dissipate excess heat when temperatures are very high, and thus, may make heat illness more likely. Almost any cardiovascular medication can make you more prone to heat illness, but this is especially true with beta blockers, calcium channel blockers, and diuretics.

So, while everyone should take precautions during a heat wave, it is especially important to do so if you have heart disease. The most important thing to do is to stay in a cool environment during the heat of the day. If you don't have air conditioning, consider going to the mall, to a church, or to a neighbor's. Avoid exertion, since the calories you burn during exercise will just produce that much more heat that your body will need to dissipate. And stay very well hydrated on hot days, preferably by drinking water (and avoiding caffeine, which is a diuretic).

If you should develop signs of heat illness, such as muscle cramps or nausea, call your doctor immediately.

And DO NOT stop any of your cardiac medications on your own, without checking with your doctor first.

July 19, 2010 at 10:10 am
(1) acharya says:

In jan 1998 I had an MI. I was diagnosed with having an unstable angina and bypass surgery was recommended after an angiogram was done. I recovered reduced my weight by a few pounds, changed my diet(I was a vegetarian) to a complex carbohydrate,low fat diet and increased my physical activity. Its 12 years and all the usual indicators are optimal with no medication. But I avoid going out when the temperature rise above 33/34*Celsius as it is extremely discomfiting. I find severe cold (below8*Celsius) very uncomfortable too and better avoided. Easy as I live in Bangalore which is quite temperate!

June 13, 2011 at 12:23 pm
(2) Carolyn Flesch says:

I really like your posts. I belong to a heart failure group on yahoogroups and we have been discussing the effects of high temperatures. I hope you don’t mind, I couldn’t get your url to copy, so I copied and pasted your whole article to the heartfailure.yahoogroups page.
Thank you for all your helpful information.

June 13, 2011 at 10:00 pm
(3) b woods says:

I work in Cardiac Rehab and for years we have educated our out patients regarding the extremes of heat and cold for the stress on their heart while recovering from heart conditions and surgeries… encouraging water intake with exercise to prevent dehydration.
I, too, appreciate the articles you generate.

June 14, 2011 at 3:58 am
(4) aditya s says:

I wish to know whether extreme heat conditions have any bearing on blood pressure of a heart patient. Though I have been diagnosed with ASD almost 32 years ago, I have no serious health problems and I have not got any heart check-up till now, by God’s grace. Could you just advice me on further precautions as at times I do have the feeling of palpatations and irregular heart beat. Of course, there is no breathlessness when these occur.

Aditya S

August 1, 2011 at 1:59 pm
(5) connie says:

My husband and I went to Kings Island. It was a hot day and he has a heart problem. He knows he has to be careful so the plan was to obviously not ride roller coasters, stay in the shade as much as possible, go on a couple of the easy going water log rides, see some shows, play games, eat and call it a day. He absolutely loves Kings Island. We were only there for one hour and hadn’t been on one single ride when he began to feel dizzy, vomitted and then passed out. I was so frightened. The EMT came and took him to the little first aid building and he woke up. They poured water on his neck and wrists and took his blood pressure. It was initially undetectable then they got the reading of 60 over 30ish. They gave him water and allowed him to cool off and after 30 minutes his blood pressure went back to normal. He had no pain at all. It was totally his blood pressure. Since then, I have researched the effect that high temperatures have on someone with heart disease. The heart cannot work hard enough to keep the body cool in hot temperatures. MY HUSBAND COULD HAVE DIED. I understand that now and I will never allow my husband to do anything else outside on days when it’s hot. Please be careful and take your doctors advice when it comes to your heart.

June 5, 2013 at 10:29 pm
(6) Georgia says:

Every now and then I would get really dizzy and the scenery around me would start to turn black. I didn’t want to tell anybody Incase it was serious. It’s happened multiple times since then. I also get frequent headaches that will last a long time or a short time. They will either hurt really badly or maybe just a feeling on the side of my forehead.

None of that really scared me, but, there’s more. It happens sometimes, but when it happens, it hurts. My whole chest will feel like its tightening around my heart and it starts to feel like a giant is laying on me. As it happens, I lose my breath. Completely. My throat feels like its scratchy and I have to take humongous breathes just to feel like there’s is EVEN air.

I don’t know if it is serious or if it is just a cold that happens to never go away.

June 10, 2013 at 1:52 pm
(7) sopje says:

Georgia please go and see a doctor!!!!!!!!

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