Heart-Rhythm Disorder Common in Long COVID Patients

A rare heart-rhythm disorder appears in nearly one in three adults suffering from severe long COVID, with a significant number being middle-aged women, according to researchers from Sweden published in Circulation: Arrhythmia and Electrophysiology.

Prior to the pandemic, this condition affected less than 1% of the Swedish population. Known as POTS, or postural orthostatic tachycardia syndrome, it leads to a rapid heartbeat when transitioning from lying down to standing, and sometimes even at rest or during physical activity. For those impacted, standing can induce dizziness, prompting them to either sit or lie down due to an inability to tolerate standing for long.

Underlying Chronic Conditions

The investigators from Karolinska Institutet looked into the prevalence and clinical ramifications of POTS in 467 patients who were not hospitalized but needed to take extended sick leave due to ongoing COVID-19 symptoms. They examined demographic factors and clinical results between those diagnosed with POTS and those without it.

About 12 months post-infection with SARS-CoV-2, participants underwent physical assessments and filled out health questionnaires. Those demonstrating symptoms of POTS had consultations with a cardiologist, who conducted various tests, including a 48-hour electrocardiogram, the 6-minute walk test, head-up tilt testing, and the active stand test.

To diagnose POTS, a heart rate increase of at least 30 beats per minute upon standing—or moving from a lie-down position—without orthostatic hypotension, alongside symptoms lasting a minimum of three months after excluding other potential conditions, was required.

Among the participants, 84% were women, and 32% had pre-existing chronic conditions before contracting COVID-19, with asthma (16%) and obesity (15%) being the most frequently reported.

Impact on Physical Activity

Overall, 31% of the long-COVID patients received a POTS diagnosis, while 27% did not fulfill the diagnostic criteria, and 42% displayed no clinical signs of the syndrome. Nearly all POTS patients were women (91%) and were generally younger than those who did not meet the criteria or showed no symptoms (average ages of 40.0, 44.0, and 47.0 years, respectively). Interestingly, most middle-aged individuals diagnosed with POTS were previously healthy and physically active before their long COVID symptoms developed.