Chapter 1: Understanding Post-COVID Cardiovascular Concerns

The reality of cardiovascular issues following mild COVID-19 is often underestimated. While these occurrences are not widespread, their impact can be significant.

Eleanor, a vaccinated friend, was diligent about her social interactions. She joined a small group of similarly vaccinated friends for a holiday dinner. Shortly after, one of them informed the group that he had tested positive for COVID-19. Eleanor immediately got tested at her local health department, which returned a negative result. However, she subsequently developed fever and fatigue that lasted for about ten days.

After recovering, Eleanor experienced alarming symptoms two months later. Upon getting out of bed, her heart rate spiked to around 130 bpm. This unsettling trend persisted every time she moved, leading to a terrifying episode where her heart rate soared to nearly 200 bpm. “I thought I was going to die,” she recalled.

Eleanor consulted her primary care physician during a period when her heart rate appeared normal. Despite a thorough examination and an electrocardiogram, everything seemed fine, leaving her with no answers. The doctor suggested, “If it happens again, come back.” Unfortunately, the troubling symptoms returned the following day, prompting further tests, including a cardiac echo and CAT scan, both of which yielded normal results. [The recent history of COVID-19 should have raised suspicion for Long COVID-related conditions like inappropriate tachycardia syndrome or postural orthostatic tachycardia syndrome (POTS). Regrettably, awareness of these conditions remains limited among many healthcare providers.] Eleanor's symptoms persisted, leading to a referral to a cardiologist.

The cardiologist, unfamiliar with Long COVID cardiac complications, was perplexed by Eleanor's symptoms and recommended wearing a Holter monitor over the weekend. After a long wait for results, she was informed by a different physician that her heart rate had reached 170 bpm on one occasion, which was concerning. “Yes, I agree. I know because I checked my pulse,” Eleanor responded. Unfortunately, the cardiologist had no actionable recommendations and remained unaware of post-COVID cardiac issues, despite Eleanor providing relevant literature.

She is now under the care of a specialist knowledgeable about Long COVID syndromes and equipped to manage heart and vascular complications arising post-infection.

Chapter 2: The Scope of Long COVID and Cardiac Health

As mentioned in my prior article, Long COVID affects 10 to 30% of those with mild COVID-19. Some individuals experience various cardiovascular symptoms. It’s crucial to clarify that this discussion focuses on those who had mild infections rather than severe cases requiring hospitalization.

Heart damage is a significant aspect of Long COVID. The coronavirus can infect all layers of the heart, as well as the pericardium, and can also impact endothelial cells lining the coronary arteries and blood vessels. This opens the door for potential damage to both the heart and vascular system. Moreover, the virus may directly affect the nervous system or induce autoantibodies that do so.

The concern is particularly acute for young, previously healthy individuals, who typically have mild or even asymptomatic infections. Early in the pandemic, a study involving 26 competitive college athletes who had tested positive for COVID-19 revealed that 46% exhibited signs of myocarditis or other cardiac injuries on MRI, even though most were asymptomatic and none required hospitalization. This was a wake-up call, highlighting that mild cases could lead to serious heart damage, including in otherwise healthy young people.

The pressing question remains: will the pandemic result in a significant number of individuals with heart damage requiring long-term care?

Eleanor’s experience illustrates post-exertional tachycardia or a related arrhythmia syndrome. POTS has been recognized as a rare syndrome long before the pandemic, often following a “viral illness.” Typically, individuals, especially young women, report symptoms such as fatigue, brain fog, memory issues, headaches, and sometimes gastrointestinal distress. This condition falls under the umbrella of dysautonomia, an imbalance of the autonomic nervous system impacting various automatic body functions like heart rate and blood pressure. The precise cause of this imbalance remains uncertain.

With the rise of mild COVID cases, POTS is being diagnosed more frequently, albeit still not common, yet it can be quite disabling. Inappropriate tachycardia syndromes, including post-exertional types, are increasingly recognized as distinct syndromes following COVID-19.

Emerging evidence suggests that the vagus nerve, which governs the parasympathetic system, may be compromised by the virus, contributing to fatigue and other systemic symptoms. Additionally, damage to the nerve endings surrounding blood vessels could disrupt normal smooth muscle contraction, affecting blood pressure regulation. This damage might not stem directly from the virus but rather from the development of autoantibodies that harm nerve endings.

Diagnosis of POTS relies heavily on patient history, with a confirmatory test involving a pulse comparison before and after standing up. An increase of more than 30 bpm is indicative of the condition. For some POTS patients, the pulse may continue to rise over several minutes after standing, while typically, it should stabilize quickly.

Prior to the pandemic, POTS was known to last varying durations, with some individuals experiencing flare-ups months later. There is currently no cure; standard management includes increased fluid intake, a high-salt diet, and the use of compression stockings, which can mitigate symptoms but not completely eliminate them. Post-COVID POTS appears to follow similar patterns.

A study involving 20 patients with autonomic dysfunction post-COVID found that 60% were unable to return to work, 25% managed to work with accommodations, while the remaining patients eventually returned to work.

Another analysis of 27 post-COVID patients referred to the Mayo Clinic uncovered a range of autonomic dysfunction manifestations, such as POTS, lightheadedness, fainting, and excessive sweating.

While inappropriate tachycardia syndromes are not common, their occurrence is significant enough, considering the approximately 80 million COVID-19 cases in the U.S. By this estimation, a considerable number of individuals may experience these syndromes and other autonomic disturbances in the year following infection. Alarmingly, many healthcare providers, including cardiologists, remain unaware of these issues.

A major study from the Veterans Affairs (VA) published in early February 2022 examined long-term cardiovascular outcomes for individuals who tested positive for COVID-19. Investigators analyzed data from 153,760 COVID-positive veterans, none of whom had been vaccinated at that time, alongside control groups of 5.5 million veterans who had not tested positive and another 5.5 million who sought care in the year preceding the pandemic.

Evaluating cardiovascular outcomes from 30 days post-infection to 12 months, the study revealed a notable number of individuals developing cardiovascular conditions such as irregular heartbeats, heart muscle damage, angina, heart attacks, heart failure, and blood clotting issues, including strokes. These diagnoses were compared against the control groups to ascertain their frequency.

The COVID-positive cohort was categorized based on severity—those who were never hospitalized, those who were hospitalized, and those requiring ICU care.

While severe COVID cases presented numerous instances of ongoing or new cardiovascular disorders, interestingly, individuals with mild COVID also showed significant numbers, leading to approximately 20 additional cases per thousand compared to control expectations.

The authors noted that COVID-19 posed a risk across demographics, affecting the young and old, those with pre-existing conditions, and those without.

In summary, while the risk of cardiovascular disease in non-hospitalized individuals with mild COVID-19 is relatively low, it can still represent a serious concern for many. This article has addressed heart muscle damage in young, healthy individuals, autonomic dysfunctions like inappropriate tachycardias and POTS following mild COVID, and the potential for severe cardiovascular diseases post-infection.

With nearly 80 million confirmed COVID-19 cases in the U.S., it is sobering to consider the vast number of individuals with mild COVID who may develop autonomic dysfunctions and various cardiovascular diseases within the first year after infection.

Join me next time for a discussion on the mental health and neuropsychiatric syndromes that can occur following mild COVID-19.

Stephen C. Schimpff, MD, MACP, is a quasi-retired internist, professor of medicine, former CEO of the University of Maryland Medical Center, and author of "Longevity Decoded — The 7 Keys to Healthy Aging" as well as "BOOM — Boost Our Own Metabolism," co-authored with Dr. Harry Oken.