Here in the Southeast, temperatures have soared this summer. Extreme heat can be uncomfortable and it can put additional strain on the cardiovascular system. Dr. Noreen Kelly, a cardiologist at Atrium Health Sanger Heart & Vascular Institute, explains how heat can affect your heart health and what you can do to stay safe when temperatures climb.
How the heat can affect your heart
“It’s been consistently shown that heat can increase our risk of heart attack, stroke, heart failure, hospitalization, abnormal heart rhythm and sudden cardiac death,” says Kelly.
When your body gets hot, it works harder to cool itself. Blood vessels widen to help release heat through the skin, which can lower blood pressure. That can be especially significant for people who are already prone to low blood pressure because of an underlying health condition or medications such as blood pressure-lowering drugs or diuretics, she explains.
Sweating and dehydration can also reduce the amount of fluid circulating in the body and disrupt electrolyte levels. In response, the heart may need to beat faster and work harder to maintain blood flow and blood pressure.
“Our heart rate has to go up to maintain our blood pressure,” she says. “As our heart rate goes up, our heart has to work harder. When our heart works harder, that’s more stressful on our heart, especially for people who have an underlying heart condition.” Electrolytes, including sodium and potassium, also play an important role in maintaining a normal heart rhythm.
“We rely heavily on having normal electrolyte levels in our body to maintain a normal heart rhythm,” says Kelly. “When those electrolyte levels get out of whack, we can predispose ourselves to having abnormal heart rhythms.”
Ask your doctor if supplementing with electrolyte drinks or powders is safe for you.
How to protect your heart in extreme heat
When temperatures soar, Kelly recommends spending as much time as possible in air-conditioned spaces. If you do go outside, aim for cooler morning or evening hours, take frequent breaks, seek shade when possible, use a portable fan and drink water before, during and after time in the heat.
If you have heart failure, follow a fluid restriction or take medications that affect blood pressure or fluid balance, ask your healthcare provider how to adjust your hydration plan during extreme heat. Don’t change your medications or fluid intake on your own.
“Exercise is important, so we don’t want people to stop exercising in these extreme temperatures, but want to make sure they know how to do it safely,” she says.
On especially hot days, that may mean shortening an outdoor workout, moving it to a cooler time of day or exercising indoors instead.
Pay attention to your local air quality index
In addition to checking the weather forecast, pay attention to your local Air Quality Index (AQI). Heat can worsen air quality and air pollution can place additional stress on the heart and lungs.
“Poor air quality can make it challenging to breathe, especially if you have an underlying lung condition, which is just another added stress on your body,” says Kelly. “Our heart and lungs work together, so if it’s really hot and the quality isn’t good, it can be especially stressful on the body.”
When to seek medical attention for heat-related illness
Pay attention to how you feel when you’re outside in the heat. Dizziness, headache, nausea, weakness, heavy sweating or shortness of breath can be signs that your body is becoming overheated. Stop what you’re doing, move to a cooler place and let someone know you aren’t feeling well.
If you feel lightheaded or like your heart is racing, Kelly recommends resting in a cool area and contacting your physician if symptoms persist or you’re concerned. Follow your care team’s recommendations for hydration, particularly if you have heart failure or have been told to limit fluids.
Confusion, loss of consciousness, seizures or a very high body temperature can be signs of heat stroke, which is a medical emergency. Call 911 and begin cooling the person while waiting for help.
Older adults and people who have had a heart attack or stroke, have heart failure, or take medications that affect blood pressure or fluid balance may be particularly susceptible to extreme heat.
Finally, Kelly recommends building a relationship with a primary care provider or cardiologist who can help you understand your individual risk factors and make a plan to stay safe during extreme heat.
Learn more about heart care at Atrium Health Sanger Heart & Vascular Institute.
