COVID-19 (Coronavirus disease-2019), caused by the strain of coronavirus strain called severe acute respiratory syndrome corona virus-2019 (SARS-CoV-2) created a global pandemic that has affected the lives of billions of people. A novel coronavirus (nCoV) was identified on 7 January 2020 and was temporarily named “2019-nCoV”. It was subsequently named the “COVID-19 virus”. 2022 marks grim milestone as its been 2 years since WHO categorized the COVID-19 outbreak as a pandemic – a health emergency spanning countries and continents. More than 6 million people have died from this disease worldwide.
COVID-19 primarily causes severe viral pneumonia but it can also cause respiratory, gastrointestinal, central nervous systems, and cardiovascular diseases such as myocardial injury, arrhythmias, ACS, and thromboembolism. Myocardial injury associated with COVID-19 is a high cause of mortality.
MedPiper Technologies and JournoMed in association with Frontier Lifeline Hospital, Chennai conducted a webinar on April 16th, 2022 titled “Diagnosis and Management of CVD During COVID Treatment” where the speaker Dr. Anup S Charles highlighted how COVID-19 causes CVD and how to diagnose and treat them. Dr. Anup S Charles is the Paediatric Cardio Thoracic and Vascular Surgeon at Frontier Private Limited.
How COVID-19 infects cells?
The coronavirus consists of long RNA polymers packed into the center of the particles, surrounded by a protective capsid. The capsid is a lattice of repeated protein molecules referred to as a coat or capsid proteins. In coronavirus, these proteins are called the nucleocapsid. The coronavirus core particle is further surrounded by an outer membrane envelope made of lipids (fats) with proteins inserted. These membranes are derived from the cells in which the virus was last assembled in but are modified to contain specific viral proteins. These proteins include the spike (S), membrane (M), and envelope (E) proteins.
Coronaviruses primarily infect human lung cells through a receptor for an enzyme called Angiotensin Converting Enzyme 2 (ACE2). The first step leading to viral infection is when the virus spike protein recognizes and binds to the ACE2 receptor. The virus then enters the lung cells and the viral RNA is released into the cytoplasm. The viral RNA molecules recruit the cellular apparatus to make thousands of copies of the viral RNA. It also instructs the cells to synthesize hundreds of thousands of nucleocapsid, membrane, envelope, and spike proteins. These assemble into new virus particles which bud out of the cell surface membrane. The cells release the newly formed viral particles propagating the infection and eventually die.
Causes of CVD due to COVID-19
Analyses of prior coronavirus outbreaks and COVID-19 data suggest several potential mechanisms of COVID-19 related myocardial injury. SARS-CoV-2 may directly infect and attack the cardiac cells and cause severe cellular and organ-wide pathology and dysfunction. Fulminant Myocarditis, an uncommon syndrome characterized by sudden and severe cardiac inflammation often causes death due to cardiogenic shock, ventricular arrhythmias, or multiorgan system failure, is relatively uncommon in COVID-19.
Temporary damage to heart tissues may occur due to several reasons:
- Lack of oxygen. As the virus causes inflammation and fluid to fill up the air sacs in the lungs, less oxygen reaches the bloodstream. The heart has to work harder to pump blood through the body, which can be dangerous in people with pre-existing heart disease. The heart can fail from overwork, or insufficient oxygen can cause cell death and tissue damage in the heart and other organs.
- Myocarditis or inflammation of the heart. The coronavirus may infect and damage the heart’s muscle tissue directly, as is the case with other viral infections, including some strains of the flu. The heart muscles are damaged indirectly by the body’s immune system response.
- Coronavirus infection also affects the inner surfaces of veins and arteries, which causes blood vessel inflammation, damage to very small vessels, and blood clots. All of these events compromise blood flow to the heart or other parts of the body. “Severe COVID-19 is a disease that affects endothelial cells, which form the lining of the blood vessels,” says Dr. Charles.
- Stress cardiomyopathy. Viral infections causes cardiomyopathy, a heart muscle disorder that affects the heart’s ability to pump blood effectively. When attacked by a virus, the body undergoes stress and releases a surge of chemicals called catecholamines, which can stun the heart. Once the infection resolves, the stressor has ended and the heart can recover.
Managing CVD and how to reduce its symptoms
After a COVID-19 infection, if person experience a rapid heart rate, they must contact the doctor. A temporary increase in heart rate can cause dehydration. Drinking enough fluid is essential. Symptoms of a rapid or irregular heart rhythm may include:
- Feeling your heartbeat rapidly or irregularly in your chest (palpitations)
- Feeling lightheaded or dizzy, especially upon standing
- Chest discomfort
In case of people suffering from life-threatening arrhythmias, inflammation increases the duration of the ventricular repolarization (QTc) interval. Dr. Charles says that these patients must be closely monitored more as they are at higher risk. Agents such as hydroxychloroquine, azithromycin, and lopinavir/ritonavir are being increasingly used in post-exposure prophylaxis or treatment of COVID-19 patients,. These agents may increase the risk of QTc interval prolongation, ventricular tachycardia, and cause sudden cardiac death.
All patients with acute neuro/cardiovascular events, including acute myocardial infarction (AMI) and acute ischemic stroke (AIS) are recommended to follow the overarching COVID-19 protocol to screen for any positive cases to minimize the risk to healthcare workers. Healthcare workers should be more responsible in the care of patients with diabetes and cardiovascular disorders infected with COVID-19. These patients face higher threats to their well-being as they are at risk of exposure to a high viral load. Continuous consultation with a cardiologist can help to detect and capture these issues early on, thus helping with timely treatment.