Although COVID-19 is primarily a respiratory or lung disease, the heart can also suffer. As the virus causes inflammation and fluid to fill up the air sacs in the lungs, less oxygen can reach the bloodstream. The heart has to work harder to pump blood through the body, which can be dangerous in people with
preexisting heart disease. The infection may infect and damage the heart’s muscle tissue directly, as is possible with other viral infections, including some strains of the flu. Coronavirus infection also affects the inner surfaces of veins and arteries, which can cause blood vessel inflammation, damage to very small vessels and blood clots, all of which can compromise blood flow to the heart or other parts of the body.
Viral infections can cause 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.