Long COVID tied to lasting autonomic dysfunction

Patients with long COVID may experience persistent autonomic dysfunction comparable to those with pure autonomic failure, reveals a study.

The researchers classified patients referred for autonomic testing as follows: long COVID (acute COVID-19 infection ≥12 weeks before testing), controls (COVID-19 negative, normal autonomic tests), and pure autonomic failure (COVID-19 negative, abnormal autonomic testing). They recorded heart rate and blood pressure during active standing, Valsalva maneuver, respiratory sinus arrhythmia, and tilt-table testing.

Patients with long COVID demonstrated greater heart rate increase and blood pressure decrease with active standing and tilt-table testing (p<0.05 for all) than controls. They also had lower Valsalva ratios and respiratory sinus arrhythmia values (p<0.05 for both).

When compared with pure autonomic failure patients, those with long COVID showed a higher heart rate increase but a lower decrease in blood pressure with active standing and tilt-table testing, as well as lesser Valsalva ratios and respiratory sinus arrhythmia values (p<0.001 for all).

Following adjustments for age and sex, patients with long COVID exhibited similar autonomic dysfunction measures to those with pure autonomic failure. Moreover, patients referred up to 40 months after infection were found to have autonomic testing abnormalities.

“Long COVID is believed to be associated with autonomic dysfunction, but the nature and severity of any autonomic disturbances are not well understood,” the researchers said.