Increased heart risks due to passive exposure to heat: Study

Prolonged heat exposure has been related with heart ailments and increased complications in adults with coronary artery disease (CAD), a new study has revealed.

Heat exposure boosts myocardial blood flow and induces ischemia in some with coronary artery disease, study published on June 10 in Annals of Internal Medicine said.

Ischmeia refers to the inadequate blood supply to tissues, often because of blockage in the arteries resulting in serious health conditions like heart attacks, strokes, or peripheral artery disease.

The conclusions were based on a laboratory-controlled experiment which showed that passive heat exposure was enough to increase myocardial blood flow (MBF) in all participants, irrespective of age and health status, which creates significant stress on the heart.

The researchers observed asymptomatic heat-induced myocardial ischemia in some participants with CAD, which suggested that these adults may minimize the risk of cardiac strain during extreme heat by staying cool. 

With 2023 being reported the warmest year on record for planet Earth, and the world’s median temperature increasing much more rapidly than it was at the beginning of this century, more and more individuals are likely to be exposed to the intense heat.

According to a study published on April 19 in the peer-reviewed PLOS Climate, nearly 90% of India is in a “danger zone” from heatwave impact and almost all of Delhi is at the risk of severe heatwave impacts.

“In the context of warming global temperatures the frequency of extreme temperature events is increasing and will continue to negatively impact population health,” Lead study author Dr. Daniel W. Riggs, assistant professor of medicine in the Christina Lee Brown Envirome Institute at the University of Louisville explained.

He added that heat exposure is an important yet ignored risk factor that contributes to heart disease, reported Medical News Today.

“A better understanding of the effects of heat on health, including heart health, is necessary to develop evidence-based approaches to help mitigate and prevent future climate-related impacts on health and well-being.”

“Although the link between cardiovascular disease and exposure to high heat is well established, the mechanisms and exposure pathways that promote the development of cardiovascular disease are complex and require more research. Therefore, our interest was to try to develop a better understanding of how exposure to high temperatures may contribute to immune-inflammatory activation, Riggs was quoted as saying.

However, cardiovascular disease risk factors largely increase because of cigarette smoking, diabetes, obesity, hypertension, high cholesterol, hereditary causes with proven evidence establishing cause and effect relationship,” an interventional cardiologist at Hackensack University Medical Center in New Jersey said after reviewing the study.