Chronotropic Incompetence in Non-Hospitalized Patients with Post-COVID-19 Syndrome

Abstract

Patients recovering from COVID-19 commonly report persistence of dyspnea, exertional fatigue, and difficulties in carrying out their daily activities. However, the nature of these symptoms is still unknown. The purpose of the study was to identify limiting causes of cardiopulmonary origin for the performance of physical exercise in post-COVID-19 condition that could explain the symptomatic persistence of dyspnea or fatigue-related symptoms. Thirty-two non-hospitalized patients with post-COVID-19 condition (i.e., still presenting a chronic symptomatic phase lasting >90 days since debut of symptoms that lasted for at least 2 months and cannot be explained by an alternative diagnosis) completed a clinical examination including echocardiography, submaximal and maximal cardiorespiratory fitness tests (Ekblom-Bak and Bruce’s protocols), and a battery of validated questionnaires about fatigue and exercise intolerance. Four participants (12.5%) reported an abnormal cardiac response to exercise during the submaximal test, which aroused suspicion of the presence of chronotropic incompetence. All of them were confirmed with a positive diagnosis maximal exercise test after cardiology screening, even with a comprehensive clinical examination, resting ECG, and echocardiogram, without other findings. No statistical differences were found in any physiological variables or questionnaire values, between patients with positive and negative diagnoses. Chronotropic incompetence and other autonomic disorders may appear in patients with mild forms of COVID-19 presentation and may persist in the long term, being responsible for exercise intolerance after resolution of acute infection. Clinicians should be aware that chronotropic incompetence and other autonomic disorders may be a complication of COVID-19 and should consider appropriate diagnostic and therapeutic interventions in these patients, especially when early exercise-related fatigability is reported.

Protective effect of BNT162b2 vaccination on aerobic capacity following mild to moderate SARS-CoV-2 infection: a cross sectional study, Israel, March-December 2021

“…These results suggest chronotropic incompetence in the unvaccinated group, with a reduction in the peak-exercise HR and VE, contributing to limited exercise capacity. Similar results have been demonstrated for HR in other studies [7,8]. In our cohort we show that there is also a difference in ventilation (V’E), with lower values for the unvaccinated group.…”

Reduced exercise capacity, chronotropic incompetence, and early systemic inflammation in cardiopulmonary phenotype Long COVID

“…Four other studies have also found that chronotropic incompetence contributes to exercise limitations in PASC. 23,[85][86][87] Similarly, "dysautonomia" defined by heart rate parameters was associated with lower peak VO2 in PASC. 87 Chronotropic incompetence is not a universal finding in PASC; some exercise protocols make ascertainment of chronotropic incompetence difficult, sensitivity and specificity vary with exercise modality, and including sub-maximal tests or patients on beta-blockers reduces specificity.…”

“…38 Jimeno-Almazán et al found chronotropic incompetence on CPET using a cycle ergometer and confirmed by treadmill testing among 4/32 individuals (13% of study sample) with reduced exercise capacity after COVID-19. 39 Ladlow et al found that dysautonomia as defined by heart rate parameters (resting HR>75, HR increase <89 bpm, and HR recovery at 1 minute <25 bpm) 40 was associated with lower peak VO 2 among individuals with PASC. 41 Our findings build upon these earlier studies by demonstrating chronotropic incompetence at 18 months following COVID-19 and also including evaluation of cardiac inflammation, structural heart disease and cardiovascular arrhythmias in study participants along with including recovered individuals as a comparator group and adjusting for confounders in our models.…”

Impaired Vagal Activity in Long-COVID-19 Patients

“…Standardized protocols also make our study very valuable. Few studies have investigated dysautonomia in Long-COVID-19 patients using different methods [ 6 , 34 ]; therefore, a comparison with previous results is difficult.…”