The Covid-19 pandemic continues its endless parade around the world, with virus variants and their offspring still walking the ramp while making surprises with changes to fresh spike protein outfits and other antigen accessories. While face masks and vaccines try to slow the epidemic and reduce mortality, there are concerns about survivors revealing the long-term effects of the infection even after the initial acute phase has subsided.
This phenomenon, known as long covid, has been observed since the early waves of 2020 and seems to be continuing in the variants of 2021. It is still necessary to evaluate the extent of this long-term pain in the Omicron family variant. The disease is reported to be less serious. The virus may have tampered with its virus or its effects may have been weakened by a previous infection or a vaccine-derived immunity. In any case, the risk of long covid appears to be lower with Omicron than with the previous virus.
The definition of long covid has taken time to develop. The World Health Organization (WHO) has defined it as a covid attributable symptom that appears three months after an acute infection. According to the WHO, “The condition after Covid 19 appears in individuals with a history of possible or confirmed SARS-CoV-2 infection, usually the symptoms last for at least two months and may not occur within three months of the onset of Covid-19. Explained by alternative diagnosis.” The Center for Disease Control (CDC), USA, considers the symptoms of acute illness to last longer than four weeks as a sign of a long colic. The UK’s National Health Service (NHS) classifies ‘going symptomatic covid-19’ (4-12 weeks) and ‘post-covid-19 syndrome’ (over 12 weeks).
Scientific reports, published from around the world, differ in the estimates of long covids based on the criteria they use. A recent analysis by the CDC, from millions of health records, reported an estimated 20 percent of this pain among coward survivors. This may have excluded people who do not have access to health care for a variety of reasons. A previous household survey by the CDC reported in June of this year identified a rate of one in three people. A meta-analysis of global data collected from several studies published in March 2022 puts the prevalence of Long Cowid at close to 50 percent of all survivors. Whatever the actual percentage, the overall numbers are a matter of great concern as a large number of Kovid survivors appear to have compromised their health and well-being.
The long-term health effects of covid can be caused by one or more of the following factors: (1) the effects of organ damage caused directly by the virus; (2) the residual effects of injuries caused by the body’s strong immune response to fight the virus; (3) other related health conditions, especially diabetes, exacerbated by covid-trigger inflammation; (4) neglect of other health conditions through medical care focused solely on covid management; (5) Side effects of drugs and techniques used for covid care, such as steroids and psychological stress arising from intensive care. The reactivation of a latent infection with the Epstein-Barr virus has also long been implicated as a cause of covid.
Chronic fatigue has been noted with some other viral infections, and chronic disease with coronavirus associated with SARS-1 and MERS has also been observed, with a very long association with the covid virus and the human body. . The initial tendency of doctors to dismiss the complaints of Kovid victims completely psychologically has proved to be a wrong and inappropriate assessment.
Many clinical features of Long Covid have been described, including diseases of various organs from the brain and heart to the gastrointestinal system and pancreas. In addition to the direct tissue damage caused by the virus, there is some evidence to suggest that the tenth cranial nerve (the vagus) may be affected. It is the longest hair nerve, hence its name because it is a ‘wanderer’ that controls and regulates many important organs from the brain to the chest and abdomen.
Although long covid can affect many organs and body functions, its effect on the heart and blood vessels has attracted a lot of attention. Inflammation of the heart muscle (‘myocarditis’) can be caused either by the direct effect of a virus that damages the muscle fibers or as a result of an immunological injury caused by the body’s own immunity. The pericardium, the lining of the heart, can also be inflamed (‘pericarditis’). People who die from covid have been found to have damage to the heart muscle. Among survivors, evidence of heart attack involvement comes from evidence of increased muscle levels of enzymes released by damaged heart muscle, decreased pumping capacity of the heart muscle indicated by echocardiography or radionuclide imaging, and muscle fiber damage shown by magnetic resonance imaging. MRI). Impaired heart function is reflected in symptoms of fatigue, decreased exercise tolerance, and deep chest pain, although clinical symptoms of heart attack are rare in people without pre-existing heart disease.
Incidence of heart attack involvement in covid is difficult to measure because only a fraction of covid survivors can make a detailed assessment. In the pre-Omicron era, 10 weeks after Valentina Pontman tested positive for the virus in Frankfurt, she studied 100 patients in a row. They performed cardiac MRI with gadolinium contrast agent. They found heart abnormalities in three of the four patients. Impaired pumping function of the heart, inflammation of the heart muscle or fibrosis and pericarditis were detected. Although most patients recovered within six months, the symptoms lasted from a few years to a year.
Heartbeat can also be abnormal. The vagus nerve, which slows down the heart rate, usually controls the heartbeat. When that inhibitory effect wears off, the stressed body pumps adrenaline and other catecholamines, causing the heart to run wild. This can be exacerbated when a person stands up – called postural orthostatic tachycardia syndrome (POTS). In this pain, within 30 minutes of standing, more than 30 beats in adults and more than 40 beats in children increase the heart rate. There may also be irregular heartbeats (‘missed beats’ or ‘arrhythmias’).
When the lungs are affected by covid, stress can also occur in the heart. Fibrosis of the lungs makes the heart more resistant to pumping blood to the heart and even damaged lungs do not effectively oxygenate the blood that returns to the heart. In the acute phase of covidosis, blood clots caused by damaged blood vessels can disappear when the person is active. When clots from the veins travel to the blood vessels of the lungs (‘pulmonary embolism’), they can cause severe blood circulation collapse. Because of the increased risk of vascular damage and clots, covid survivors show a higher risk of heart attack even one year after the initial infection.
The inner lining of blood vessels (endothelium) is a dynamic structure, which responds to different conditions of blood flow needs and helps to dilate or constrict arteries while keeping blood pressure within the desired range. Covid causes endothelial dysfunction, which results in blood vessels losing the ability to dilate when needed. It can cause high blood pressure, rapid atherosclerosis and heart attack. Covid also observed an increased risk of chronic erectile dysfunction in men due to a lack of endothelial vasodilation in the blood vessels of the male genitalia.
Long covid has been implicated in a number of cardiovascular disorders, but most survivors of covid do not need to fear that their effects will be permanent. Many people who experience the effects of long covid recover over time, especially if the initial infection was mild and there is no recurrence. The recovery time depends on the severity of the initial infection, the age of the person and the associated co-morbidities. It is best to avoid the risk of infection by wearing a mask and getting vaccinated as advised to avoid serious diseases that can lead to long-term colic. No specific treatment is available yet, but the study of Long Covid is still a developed field. So far, ‘Mask Up’ and ‘Vaccinate’ are the best prevention advice.
(Prof. K. Srinath Reddy, Cardiologist, President of the Public Health Foundation of India (PHFI). The views expressed are personal.)