ABSTRACT
Background: The infection caused by the SARS-CoV-2 continues affecting millions of people worldwide and vaccines to prevent the coronavirus disease (COVID-19) are considered the most promising approach for curbing the pandemic. Otherwise, cardiovascular and neurological complications associated with the vaccines were speculated and some few case reports were published. Objective(s): We describe a case of postural orthostatic tachycardia syndrome (POTS) after viral vector COVID-19 vaccination and the possible autoimmune process of the syndrome. Method(s): A 35-year-old female, without previous symptoms or comorbidities, developed intermittent palpitation, intense fatigue and dyspnea, compromising her daily activities, triggered by upright position, seven days following the second dose of the Oxford vaccine. Physical examination was normal, except for a heart rate (HR) increase of 33 beats/min from supine to standing position, with no significant change in blood pressure and reproduction of symptoms. Result(s): A 24-hour Holter monitoring revealed episodes of spontaneous sinus tachycardia correlated with palpitation and fatigue. Extensive diagnostic investigations excluded primary cardiac, endocrine, infectious and rheumatologic etiologies. The patient underwent an autonomic function test which demonstrated normal baroreflex sensitivity, as well as normal cardiovagal and adrenergic scores. Head-up tilt test showed persistent orthostatic tachycardia (HR increase from a medium of 84 beats/min in supine position to 126 beats/min during upright tilt), without hypotension, consistent with the diagnostic criteria for POTS. According to the current guidelines, general behavior recommendations, pharmacotherapy with low dose of propranolol associated with the autonomic rehabilitation were oriented. Along three months of follow-up, the patient reported a gradually improvement in her symptoms. Conclusion(s): POTS is a heterogeneous disorder of the autonomic nervous system characterized by orthostatic tachycardia associated with symptoms of orthostatic intolerance. Although the physiopathology of COVID-19 vaccine and autonomic disorders remains speculative, autoimmune response is one of the possible mechanisms. Based on clinic presentation, the time frame of symptom onset is consistent with other well-known post-vaccination syndromes, which may be an indicator of an autoimmune process induced by immunization. Further studies are needed to assess causal relationship between immunization and autonomic dysfunction.Copyright © 2023
ABSTRACT
BACKGROUND AND PURPOSE: Twenty-five to 50% of individuals who contract COVID-19 develop postural orthostatic tachycardia syndrome (POTS).3 The underlying etiology remains undetermined, yet there is research to support several root causes. Mechanisms such as dysautonomia, hypovolemia and prolonged bed rest leading to cardiac atrophy provide some indications.2,3,4 Recent research suggests that a structured and supervised training program that includes both aerobic and resistance components, was found to improve oxygen uptake, increase cardiac size, and increase blood volume.1,5 The purpose of this case study is to describe the successful treatment of a 13-year-old female diagnosed with POTS following COVID-19 using aerobic and resistance training. CASE DESCRIPTION: A 13-year-old female student who was being treated for hypermobility, contracted COVID-19 during her plan of care. During this time, she developed symptoms of lightheadedness, headaches, fainting episodes, dizziness and heart palpitations. Her rheumatologist performed an active head up tilt test that was negative for orthostatic hypotension but positive for tachycardia, which indicated a diagnosis of POTS. She was prescribed fluidicortisone with a dose of 1mg twice per day and returned to physical therapy. The interventions included 40 minutes of zone 2 aerobic training with a heart rate range of 151 to 171 beats per minute (BPM) on a recumbent bike and 20 minutes of resistance training of the lower extremities at rate of perceived exertion (RPE) of 7 to 8. The intensity of the aerobic training progressed to zone 3 and greater aerobic training with a heart rate of at least 171 BPM when the resting heart rate was stabilized. OUTCOME(S): The patient completed 26 visits over 4 months. Following the completion of the program, the resting heart rate of the patient returned to 76 BPM from a starting rate of 127 BPM. Heart rate response to exercise was congruent with the subjective RPE reported by the patient without any reoccurring symptoms previously experienced. An active head up tilt test was performed in the clinic without a tachycardic response indicating she was no longer positive for POTS. The patient was able to resume her previous extracurricular activities, including soccer, without symptom provocation. DISCUSSION: The physiological rationale supporting this conclusion consists of a decreased compensatory tachycardic response to upright positions, improved oxygen uptake, increased blood volume and increased cardiac size. Although there was a successful outcome to this case, there are some limitations. Psychological components should be monitored as well as a greater importance of RPE due to due to the inability to accurately detect heart intensity in the diagnosis of POTS.4,1.
ABSTRACT
About 1 out of 10 patients infected with Sars-CoV2 have persistent symptoms beyond 4 weeks and some of them meet diagnostic criteria for postural tachycardia syndrome (Long-COVID POTS). The pathophysiology of Long-COVID POTS is unknown, but autonomic dysfunction may play a role. We hypothesize Long-COVID POTS patients have impaired cardiovascular autonomic reflexes and cardiac sympathovagal balance. We conducted a case-control study with patients recruited from the Vanderbilt Autonomic Dysfunction Center and an historical population of healthy controls. Hemodynamic parameters were measured before and during 75degree head up tilt. Supine ECG and finger blood pressure were continuously measured for spontaneous heart rate variability analysis. The Low Frequency (0.04-0.15Hz, LF ) and High Frequency (0.15-0.4 Hz, HF ) oscillatory modulations of sino-atrial node discharge were computed. We included 14 Long-COVID POTS patients and 15 controls matched by age (34+/-11 vs 28+/-7;p=0.09) and BMI (26.1+/-5.3 vs 23.0+/-2.6;p=0.06). As expected, the orthostatic HR increase was higher in Long-COVID POTS compared to controls (40+/-18 vs 21+/-1, p<0.05). Spectral analysis of heart rate variability in 9 patients and 15 controls (Figure) showed that Long-COVID POTS had reduced HF (363+/-420 vs 933+/-1000 ms ;p<0.05) and similar LF (798+/-596 //////////vs 962+/-1075 ms ;p=0.68), resulting in a greater LF/HF ratio (3.7+/-2.9 vs 1.4+/-1.3;p<0.05). Patients with Long-COVID POTS have reduced markers of cardiovagal modulation, but normal cardiac sympathetic activation. Our results suggest that parasympathetic dysfunction contributes to the pathophysiology of Long-COVID POTS.