Covid aftermath hits heart 

October 5, 2025

People suffering from long Covid are more likely to develop an unusual heart rhythm disorder called Postural Orthostatic Tachycardia Syndrome (POTS), according to a new study from the Karolinska Institutet in Sweden. The condition, marked by an abnormally rapid heartbeat when moving from lying down to standing, was found to affect nearly one in three patients with severe long Covid.

The findings, published in the journal Circulation: Arrhythmia and Electrophysiology, underline a strong link between long Covid and POTS, which predominantly affects middle-aged women. Researchers examined 467 patients with severe long Covid who had not been hospitalised for their initial infection. Of these, 91 per cent were women who had been healthy and physically active before contracting Covid-19.

The study revealed that 31 per cent of the participants were diagnosed with POTS, while another 27 per cent showed symptoms consistent with the condition but did not meet the full diagnostic criteria. The remaining 42 per cent did not exhibit symptoms of the syndrome. Patients diagnosed with POTS recorded markedly higher heart rates during walking tests and reported poorer quality of life compared to those without the condition.

POTS causes a significant rise in heart rate upon standing and is accompanied by symptoms such as dizziness, fatigue, and difficulties with concentration—commonly referred to as brain fog. These are also hallmark symptoms of long Covid, which has affected millions worldwide following the pandemic.

“Previous, smaller studies have suggested a connection, but now we can confirm that POTS is a very common condition among patients with long Covid,” said Mikael Björnson, a doctoral student at the Department of Medicine, Solna, Karolinska Institutet. “This is valuable knowledge for both health care professionals and patients,” he added.

Judith Bruchfeld, Associate Professor at the same institute, said that identifying the condition is relatively simple and cost-effective. “POTS can be detected with inexpensive, simple tests that are available at all levels of health care. For those who receive a diagnosis, treatments exist that can relieve symptoms and improve quality of life,” she explained.

The researchers recommend that long Covid patients experiencing symptoms such as rapid heartbeat when standing, dizziness, brain fog, and extreme fatigue undergo evaluation for POTS. Early diagnosis, they said, can make a considerable difference in managing the condition and restoring normal functioning.

The study provides one of the most comprehensive insights yet into how Covid-19 continues to affect the cardiovascular and autonomic systems long after the initial infection, adding to the growing understanding of long Covid’s complex health impacts.