When COVID-19 Attacks the Heart, Even Without Lung Damage

The coronavirus known as COVID-19 can damage the lungs and produce pneumonia that can be deadly. But as many as an estimated 20 percent of COVID-19 patients are developing heart problems — and some are dying of heart failure or cardiac arrest.

Preliminary studies from the U.S., China and Italy by cardiac experts have found that COVID-19 can infect the heart muscle, leading to heart failure and death, even among those who showed no signs of respiratory distress. The myocardium is the muscular wall of the heart, or the heart muscle. It contracts to pump blood out of the heart and then relaxes as the heart refills with returning blood.

Patients that have some sign of injury to the heart can vary between 7 to 23 percent, explains Sandra Chaparro, M.D., cardiologist and director of the Advanced Heart Failure program at Miami Cardiac & Vascular Institute.

“The myocardium in the heart has some of the receptors that the virus can use to enter into cells and cause some damage,” said Dr. Chaparro, M.D. “Although the heart muscle damage is not as extensive or frequent as when COVID-19 attacks the respiratory tract — but it has been seen that the virus can also attack the myocardium.”

While infection of the myocardium is a direct attack on the heart, there are three “pathways” that COVID-19 can take on its way to cardiovascular distress.

“There are three different pathways the virus takes affecting the heart,” says Dr. Chaparro. “One is what we call a direct injury, when it’s directly affecting the muscle (myocardium). Another one is when there is a lack of oxygen because the virus is attacking the lung – in this case we observe that hypoxemia (below-normal levels of oxygen in the blood) and respiratory failure can lead to heart problems. And then, the third pathway, is the activation of the immune system resulting in hyper-inflammation that can affect the heart as well.”

Heart disease is a primary underlying health condition that makes someone at a higher risk for developing serious complications from COVID-19. While having a pre-existing heart condition, or risk factors such as high blood pressure and diabetes, puts a person at a higher risk, even patients without any previous cardiovascular issues can succumb to direct damage to the heart from the coronavirus, says Dr. Chaparro.

In advanced COVID-19 cases, cytokines (small proteins released by cells to fight infections) can rapidly increase in number, creating inflammation as part of the immune system becoming hyper-activated. A “cytokine storm” is an overproduction of immune cells and their activating compounds. Such a storm can prove too much for the heart’s blood vessels, leading to heart failure or cardiac arrest. Heart failure means the heart is too weak to pump blood throughout the body. Most cardiac arrests occur when a diseased heart’s electrical system malfunctions.

Damage to the heart muscle may go undiagnosed in crowded hospitals responding to COVID-19 critical patients, says Dr. Chaparro, especially when the focus is on the lungs and overall respiratory distress.

“We may not be capturing the true damage,” says Dr. Chaparro. “Typical management of heart patients in this situation would call for a cardiac MRI or an endomyocardial biopsy (an invasive procedure used routinely to obtain small samples of heart muscle). Given the clinical situation during the crisis, that is not happening, and that is unfortunate.”

The big takeaway is that people with heart disease, high blood pressure or diabetes should continue to take any normally prescribed medications, get enough sleep, exercise if able, eat healthy, and avoid stress as much as possible. A disturbing trend that Dr. Chaparro has noticed is that there are fewer than normal patients coming to the hospital complaining of possible heart attack symptoms or other problems.

“We hope that’s because more people are resting at home and are not as active,” says Dr. Chaparro. “We hope that people are not holding back and afraid to come to the hospital when they feel symptoms related to their heart, such as chest pain.”

Telemedicine is always an option for such heart patients, she adds. “The important thing is to make sure you have plenty of medicines, that you keep good communication with your medical provider, that if you have any severe symptoms you don’t delay and call 911 if you need to go to the hospital.”