Covid-19 can also have an impact on the heart, experts say
Covid-19 can damage the heart both directly and indirectly and lead to complications ranging from inflammation of the heart (myocarditis), damage to heart cells (necrosis), heart rhythm disorders (arrhythmias), heart attack and muscle dysfunction that can lead to to acute or long-term heart failure, experts said.
“Covid-19 is a vascular disease that damages heart cells and muscles. It also leads to the formation of blood clots, both in the microvasculature and in the large vessels, which can block blood supply to the heart, brain and lungs and lead to strokes, heart attacks and respiratory failure, ”said Dr. Ravi R Kasliwal, Chairman of the Department of Clinical and Preventive Cardiology at Medanta -The Medicity Hospital.
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An American study using MRI found heart abnormalities in 78 of 100 patients who had recently recovered from Covid-19, including 12 of 18 asymptomatic patients. Sixty patients had ongoing myocardial inflammation consistent with myocarditis, the study found, which was published in the Journal of the American Medical Association Cardiology in July.
“Even people with mild or no symptoms can develop life-threatening cardiovascular complications. The worrying thing is that this is true for healthy adults without pre-existing risk factors, which increase the risk of complications, ”said Dr. Kasliwal, who recommends that all people who have recovered from Covid-19 be screened for detection of heart damage.
Extensive cardiac involvement is what differentiates Sars-CoV-2, the virus that causes Covid-19, from the six other coronaviruses that cause infection in humans, writes cardiologist Dr. Eric J. Topol, founder, director, and professor. of molecular medicine at Scripps Research. Translational Institute in La Jolla, California, in the journal Science.
The four human coronaviruses that cause cold-like symptoms have not been associated with heart abnormalities, although there have been isolated reports linking MERS-CoV-caused Middle East respiratory syndrome (MERS) to myocarditis, and heart disease to the syndrome. severe acute respiratory. Syndrome (SARS) caused by Sars-CoV.
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Sars-CoV-2 is structurally different from Sars-CoV. “The virus targets the angiotensin converting enzyme receptor 2 (Ace2) throughout the body, facilitating the entry of cells through its spike protein, along with the cooperation of proteases. The heart is one of the many organs with high expression of Ace2. The affinity of Sars-CoV-2 for Ace2 is significantly higher than that of SARS, ”according to Dr. Topol.
Topol notes the ease with which Sars-CoV-2 infects induced pluripotent stem cell (iPSC) derived cardiac cells in vitro, leading to a distinctive pattern of cardiac muscle cell fragmentation evident in autopsy reports. In addition to directly infecting the cells of the heart muscle, Sars-CoV-2 also enters and infects the endothelial cells that line the blood vessels of the heart and multiple vascular beds, leading to a secondary immune response. This causes a dysregulation of blood pressure and the activation of a pro-inflammatory response that leads to a cytokine storm, which is a potentially fatal systemic inflammatory syndrome associated with Covid-19..
Studies have found that damage to heart cells reflected in blood levels of a specific heart muscle enzyme called troponin affects at least one in five hospitalized patients and more than half of those with pre-existing heart conditions, increasing the risk of death. Patients with increased amounts of troponin also have high markers of inflammation (including C-reactive protein, interleukin-6, ferritin, lactate dehydrogenase), high neutrophil counts, and cardiac dysfunction, all of which increase the immune response.
“Increased systemic inflammatory responses and decreased blood supply due to clotting, endothelitis (inflammation of the blood vessels), sepsis, or hypoxemia (lack of oxygen) due to acute lung infection leads to indirect heart damage,” he said. Dr. Kasliwal.
Cardiovascular damage associated with Sars-CoV-2 infection may persist beyond recovery. Since the virus affects both the heart and the respiratory tract, more research is needed to understand why some people are more vulnerable to heart damage than others.