People suffering from common laryngopharyngeal dysfunction like chronic cough, hoarseness, recurrent throat clearing, especially after Covid, may be at significant risk of developing a heart attack or stroke, warns a study on Wednesday.

Researchers from the University of Southampton observed a reduction in baroreflex sensitivity — a measure of how much a person’s heart rate changes in response to changes in blood pressure — in patients with throat symptoms.

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The team noted that the findings could be explained by the Vagas nerve — which controls the autonomic nervous system — prioritising protection of the airways over less urgent functions, such as blood pressure regulation.

“Our immediate survival depends on the throat being able to separate air and food passages each time we swallow,” said lead author Reza Nouraei, Professor of Laryngology and Clinical Informatics at the University of Southampton.

“The throat does this using delicate reflexes, but when these reflexes are disturbed, for example, due to a viral infection like Covid or exposure to reflux affecting nerves in this region, the control of this critical junction becomes compromised, giving rise to symptoms like the feeling of a lump in the throat, throat clearing, and coughing,” Nouraei added.

The study, published in JAMA Otolaryngology, showed that “in patients with a faulty throat, the heart, specifically a function called baroreflex, is less well controlled”.

This can “likely impact long-term survival, as patients with reduced baroreflex function are more likely to die of a heart attack or stroke in years to come,” Nouraei said.

In the study, the team involved 23 patients admitted to ear, nose, and throat (ENT) surgery with aerodigestive symptoms like choking episodes, chronic cough, and difficult or painful swallowing. These patient’s heart rates, blood pressure, and baroreflex sensitivity were compared with 30 patients admitted to Gastroenterology with digestive (esophagogastric) symptoms.

The aerodigestive tract involves lips, mouth, tongue, nose, throat, vocal cords, and part of the oesophagus and windpipe,

While reflux was a common cause of symptoms in both groups, people in the aerodigestive group were found to have a higher resting heart rate and lower resting blood pressure. They also had lower baroreflex sensitivity than those in the digestive group.

“Now, and especially since Covid which damages nerves, we are seeing more patients with throat symptoms,” Professor Nouraei said.

“This study helps us to think about patients more holistically. As a clinician, if you can fix a problem in the throat that is potentially taking away bandwidth from the Vagus, then it frees up the nerve to give to the rest of the body”.