Understanding how long COVID can affect the heart and circulatory system (arteries and veins) is key to getting treatment to prevent serious complications.

Most people recover from a coronavirus infection after a few weeks. But some people have symptoms of COVID-19 that can last for weeks or months, a phenomenon now referred to as long COVID. People with long COVID experience a wide variety of symptoms that affect the whole body, including the cardiovascular system.

The Impact of COVID-19 on the Heart

Scientists are still working to understand how SARS-CoV-2, the virus that causes COVID-19, affects the cardiovascular system. With current data and medical knowledge, scientists think COVID-19 can affect the heart in three general ways.

Direct Infection With SARS-CoV-2

SARS-CoV-2 uses a protein called an ACE2 (angiotensin-converting enzyme 2) receptor to get inside cells to infect them. Many kinds of cells in the body have this protein, including cells in the heart.

Several research groups reported finding the virus in heart tissues, suggesting that SARS-CoV-2 might be able to directly infect the heart. Infection of the heart cells by the virus could lead to heart injury and some of the cardiac symptoms reported by people with COVID-19.

Widespread Inflammation

The immune system is a group of organs and specialized cells that fight against infections to keep us healthy. During coronavirus infection, the immune system releases signaling proteins called cytokines and recruits specialized cells to help fight off the virus. This process, called inflammation, is an important part of defending the body against infections.

But this natural immune response may also cause complications. Systemic or widespread inflammation that lasts too long can damage healthy cells and organs. Scientists suggest that widespread inflammation during COVID-19 can damage parts of the body, including the heart and the blood vessels that feed the heart.

Indirect Stress on the Heart

Severe COVID-19 can wreak havoc on other parts of the body, which may put extra stress on the heart and lead to acute cardiac injury. COVID-19-related damage to the lungs can reduce the amount of oxygen in the body, which can injure the heart.

Other issues related to COVID-19, like sepsis (a dangerous response by the body to infection) and blood clots, can also affect the heart and drive cardiovascular symptoms of long COVID. Lack of blood flow and oxygen to the heart can lead to heart failure.

Cardiovascular Disease Associated With COVID-19

Studies suggest that as many as 20 percent to 30 percent of people hospitalized with COVID-19 show signs of cardiac injury, or damage to the heart, as measured by the amount of a protein called troponin in the blood. Increased levels of troponin indicate heart damage, but different types of damage can cause these levels.

Blood Clots

Though scientists don’t fully understand why, some people with COVID-19 experience a greater risk of blood clots. COVID-19 invades the cells lining blood vessels throughout the body, which increases the risk of thrombosis, or the blockage of blood vessels by blood clots.

A pulmonary embolism happens when a blood clot blocks blood flow to the lungs, while a venous thromboembolism involves the blockage of a vein that takes blood to the heart. In each case, either oxygen or blood flow to the heart can be restricted, which can damage the heart.

Though heart attacks caused by blood clots appear to be rare during COVID-19, heart attacks caused by increased stress on the heart from low oxygen and blood flow are more common with COVID-19. Acute respiratory distress syndrome (ARDS) is also associated with cardiac injury, likely due to restricted oxygen to the heart.

Myocarditis

Myocarditis, or myocardial inflammation, describes inflammation of the heart muscle. It’s often caused by viral infections. A nationwide survey by the Centers for Disease Control and Prevention (CDC) reported that myocarditis is a relatively rare risk of COVID-19, affecting fewer than 1 percent of hospitalized COVID-19 patients.

However, the CDC notes that even though the risk for myocarditis is rare for people with COVID-19, it is about 16 times higher than the risk for people without COVID-19. Widespread inflammation during COVID-19 may damage the heart and cause inflamed heart tissues.

Rare cases of myocarditis have also been reported in some people, particularly adolescent boys, after receiving COVID-19 vaccines, although this is far less common than myocarditis from COVID-19 itself. Young athletes who have had COVID-19 should have an exam from a doctor before returning to sports and regular exercise.

Arrhythmia

An irregular heartbeat, or arrhythmia, happens when the electrical signals that control the heart muscle do not work properly. Arrhythmia can feel like your heart is skipping beats, racing, or thumping (palpitations). These are common complaints of people with long COVID.

High levels of inflammation during COVID-19 can alter the electrical signals of the heart, leading to an altered heart rhythm. A high heart rate (tachycardia) is also common in COVID-19 and can contribute to shortness of breath. Scientists suggest this is due to generally being ill rather than specific features of COVID-19.

POTS

COVID-19 can affect the cardiovascular system in a variety of ways, but one impact that may seem cardiovascular could actually be neurological (involving the brain and nerves). Doctors at Johns Hopkins Medicine note that some people recovering from COVID-19 show symptoms of postural orthostatic tachycardia syndrome (POTS).

Though POTS is a neurological issue, it affects the part of the nervous system that controls heart rate and blood flow. POTS can cause a rapid heartbeat, palpitations, brain fog, and fatigue, all of which are symptoms of long COVID.

While COVID-19 impacts nearly every system in the body, abnormalities in the heart can be particularly concerning. As scientists and doctors continue to understand how COVID-19 affects the cardiovascular system, better treatments will be available to those suffering from the long-term cardiovascular effects of COVID-19.

Talk With Others Who Understand

On myCOVIDteam, the social support network for those recovering from the effects of COVID-19, you can connect with others. Members come together to ask questions, give advice, and share their stories with others who understand.

Have you developed long COVID after having COVID-19? Have you noticed heart palpitations or other cardiovascular symptoms? Share your experience in the comments below, or start a conversation by posting on myCOVIDteam.