Nearly 1 in 3 adults with severe long COVID have rare heart-rhythm disorder, data suggest

Woman with dizziness

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An uncommon heart-rhythm disorder occurs in nearly 1 in 3 adults with severe long COVID, most of them middle-aged women, Swedish researchers write in Circulation: Arrhythmia and Electrophysiology

In contrast, the condition affected less than 1% of the Swedish population before the pandemic. POTS causes a rapid heartbeat when standing up after lying down and sometimes at rest and during exercise. Because standing up triggers dizziness, affected patients prefer to sit or lie down (orthostatic intolerance). 

A third had chronic diseases before infection

Karolinska Institutet investigators prospectively evaluated the prevalence and clinical effects of postural orthostatic tachycardia syndrome (POTS) in 467 nonhospitalized patients who took sick leave from work at least half of the time because of persistent COVID-19 symptoms. The team also compared demographic factors and clinical outcomes among those diagnosed as having POTS with those without the heart-rhythm disorder.

A median of 12 months after SARS-CoV-2 infection, patients underwent physical testing and completed health forms. Those who showed signs of POTS met with a cardiologist, who performed 48-hour electrocardiography, the 6-minute walk test, head-up tilt testing, and the active stand test. 

An increase in heart rate of at least 30 beats per minute after moving from the supine (lying face up) or upright position without orthostatic hypotension and a symptom duration of at least 3 months after ruling out other conditions was diagnostic of POTS.

Of all participants, 84% were women, and 32% had chronic diseases before their COVID-19 infection, with asthma (16%) and obesity (15%) being most common.

Less physical activity, capacity

In total, 31% of all long-COVID patients were diagnosed as having POTS, 27% didn't meet the criteria for the condition, and 42% had no clinical signs of POTS. 

Patients with a POTS diagnosis were nearly all women (91%) and younger than those who didn't meet the criteria or had no signs (average age, 40.0 vs 44.0 vs 47.0 years, respectively). Most middle-aged POTS patients were healthy and active before they developed long COVID.

It is important to know that POTS can be detected with inexpensive, simple tests that are available at all levels of healthcare.

Judith Bruchfeld, PhD

The most common symptoms were fatigue (93%), shortness of breath (70%), heart palpitations (60%), chest pressure (59%), joint pain (53%), problems concentrating (48%), abnormal sensations (47%), headache (47%), dizziness (46%), memory loss (45%), and cough (41%), but the distribution of symptoms was similar across the groups.

POTS patients were significantly less physical active than the other two groups on the Frandin-Grimby scale and reported lower health-related quality of life. Heart rates during the 6-minute walk test while walking and at rest were elevated over a significantly shorter walking distance (448 meters [m] vs 472 m vs 509 m, respectively), but lung-function test results were similar among the groups.

"In this cohort of predominantly younger women with highly symptomatic long COVID, POTS is common and presents with overlapping symptoms between POTS and non-POTS patients," the researchers wrote. "Long COVID POTS confers lower physical activity and capacity compared with non-POTS long COVID and should be systematically assessed in this condition."

The research team will conduct 4- and 5-year follow-up of both POTS patients and COVID-19 survivors who were originally hospitalized to investigate recovery trajectories and functional levels over time.

"It is important to know that POTS can be detected with inexpensive, simple tests that are available at all levels of healthcare," senior author Judith Bruchfeld, PhD, said in a Karolinska news release. "For those who receive a diagnosis, there are treatments that can alleviate symptoms and improve quality of life."

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