Long Covid and its effects on the cardiovascular system
Long Covid, also known as post-acute sequelae of Sars-CoV-2 infection, is a condition characterised by a constellation of symptoms that persist for weeks or months after the acute phase of Covid-19 infection. While respiratory complaints have been the primary focus, mounting evidence suggests that long Covid can exert a significant toll on the cardiovascular system.
What are the symptoms of Long Covid?
Long Covid patients often report a wide range of cardiac symptoms, including chest pain, air hunger, shortness of breath and fatigue.
In addition, a subset of patients may experience a condition called Postural Orthostatic Tachycardia Syndrome or POTS, where a range of at-times debilitating symptoms develop, including palpitations, light-headedness, brain fog, and exercise intolerance. The symptomatology can overlap with other long Covid presentations, making it challenging to diagnose.
However, POTS can often be identified by a significant increase in heart rate upon transitioning from a flat to a standing position, typically exceeding 30 beats per minute or reaching a heart rate over 120bpm within ten minutes of standing. There may be some drop in blood pressure too.
Long Covid symptoms are not limited to individuals who suffered severe acute Covid-19 infection, but have also been observed in those with mild or asymptomatic cases. They have been noted in patients who had acute cardiac involvement by the initial covid-19 illness, and in those who had not.
What are the mechanisms for long Covid?
The mechanisms underlying the cardiac involvement in long Covid are multifaceted:
• Sars-CoV-2 has been shown to directly infect cardiac cells, leading to myocardial inflammation, oxidative stress and cellular damage
• The virus can also trigger an exaggerated immune response, potentially leading to autoimmune-mediated myocarditis or vasculitis
• In POTS patients in particular, Sars-CoV-2 may directly impact the autonomic nervous system controlling heart rate and blood vessel function. This can result in a failure to maintain appropriate blood pressure and/or heart rate upon standing
• Long Covid is often associated with chronic inflammation and hypercoagulability (or tendency for clotting), both of which can contribute to atherosclerosis, thrombosis, and microvascular dysfunction, further compromising cardiac health
How to diagnose heart involvement in long Covid?
It can be challenging, as many patients present with symptoms that may not be accompanied by obvious abnormalities on routine cardiac tests.
Diagnostic modalities, including electrocardiography, echocardiography, and cardiac MRI, may be utilized to assess cardiac structure and function. Specific biomarkers such as troponin and B-type natriuretic peptide can aid in the detection of myocardial damage and stress.
However, a holistic approach involving clinical history and multidisciplinary evaluation is often necessary.
When POTS is suspected, assessing heart rate and blood pressure while sitting and standing up can help, along with possibly more advanced tests such as a cardiac rhythm monitor or a “tilt table” challenge.
What are the prevalence of long Covid, its typical age group, and its duration?
The exact frequency of long Covid after coronavirus infection is not well established, as it varies depending on the definition of long Covid and the population studied, with published series reporting ranges between 7 per cent and 45 per cent.
Long Covid could affect individuals of all ages, including children, adolescents, and adults. Research indicated that while older adults and individuals with underlying health conditions might be at a higher risk of severe acute Covid-19 infection,
Long Covid was not limited to these groups. Young, otherwise healthy individuals also reported long Covid symptoms.
The duration of long Covid varied widely among individuals. Some experienced symptoms for several weeks, while others reported symptoms persisting for several months. It was not uncommon for long Covid symptoms to fluctuate or evolve over time. Some individuals experienced relapses or new symptoms even after an initial improvement.
What are the long term implications of cardiac long Covid?
They are a subject of active research. It is possible that individuals with long Covid may be at an increased risk of persistent cardiovascular symptoms, such as recurrent chest pain or shortness of breath, reduced exercise capacity, and impaired quality of life.
Moreover, the potential for chronic inflammation and fibrosis in the heart raises concerns about future cardiovascular disease risk. Therefore, ongoing monitoring and cardiovascular risk factors management are essential for individuals affected by cardiac long Covid.
How to manage long Covid?
Rehabilitation and exercise programs tailored to individual capabilities can help improve heart fitness and reduce symptoms.
In some cases, anti-inflammatory or immunomodulatory therapies may be considered to address the underlying mechanisms.
In addition, for patients with POTS in the context of long Covid, lifestyle modifications, such as increasing salt and fluid intake and compressive leg stockings are often recommended. Medications such as beta-blockers, alpha-agonists, and volume expanders (such as some steroids) may be prescribed to help manage symptoms.
To conclude, long Covid has wide-ranging effects on the cardiovascular system and poses significant challenges for both patients and healthcare providers. It is an evolving medical research field, and efforts to improve its diagnosis, treatment and prevention are paramount to preserving the cardiac health of those affected by this condition.
• Joe Yammine, MD, is a consultant cardiologist at the Bermuda Hospitals Board. The information here is not intended as medical advice or as a substitute for professional medical opinion. Always seek the advice of your physician