A new study published in the Journal of the American College of Cardiology: Heart Failure found that many patients with long-Covid continue to have breathing problems and symptoms of chronic fatigue syndrome even months after their diagnosis of Covid-19.

The study included 41 patients aged 23 to 69 years who had suffered acute Covid-19 three to 15 months before their enrollment in this study and were currently experiencing unexplained dyspnea for almost 9 months after recovering from the infection. There were 23 women and 18 men. Their pulmonary function tests, chest X-rays, chest CT scans and echocardiograms showed no abnormal findings. During the study, they underwent cardiopulmonary exercise testing (CPET) and were evaluated for symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). “Peak oxygen consumption (peak VO2), slope of minute ventilation to CO2 production (VE/VCO2 slope) and end tidal pressure of CO2 (PetCO2) were measured”. Rapid erratic breathing was defined as dysfunctional breathing.

 “They were asked to estimate how much in the previous six months had fatigue reduced their activity at work, in their personal life and/or in school; and how often they had experienced sore throat, tender lymph nodes, headache, muscle aches, joint stiffness, unrefreshing sleep, difficulty concentrating or worsening of symptoms after mild exertion. ME/CFS was considered present if at least one of the first criteria were rated as being impacted substantially and at least four symptoms in the second criteria were rated as moderate or greater.”

Almost half of the study participants (46%) met the criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Majority of the patients (88%) showed abnormal ventilatory patterns with dysfunctional breathing, commonly seen in asthmatics. They also had increased VE/VCO2 and/or hypocapnia PetCO2 <35. Around 58% (24) patients had peak VO2 less than 80% predicted and showed circulatory impairment in the form of limitation to peak exercise performance from either cardiac dysfunction or heart failure.  Out of the 17 patients who exhibited normal peak VO2, 15 had ventilatory abnormalities in the form of peak respiratory rate >55 or dysfunctional breathing. Patients also had low CO2 values at rest and with exercise indicative of chronic hyperventilation.

This study has for the first time shown an association between long Covid and chronic fatigue syndrome. Reduced exercise capacity and abnormal breathing patterns (rapid, shallow breathing) in many patients were evident on cardiopulmonary exercise tests affecting their normal activities of daily life. The dysfunctional breathing and chronic fatigue syndrome may be the reasons for persistence of symptoms after recovering from Covid. Such patients should be evaluated by a cardiopulmonary exercise test (CPET). Breathing exercise may help in such cases.

Reference

1. Mancini DM, et al. Use of cardiopulmonary stress testing for patients with unexplained dyspnea post–coronavirus disease. JACC: Heart Failure. 2021;9(12): 927-937, https://doi.org/10.1016/j.jchf.2021.10.002.