SARS-CoV-2, the virus that causes COVID-19, most commonly affects  the lungs  but It can also lead to serious heart problems. Lung damage  caused by the virus prevents oxygen from reaching the heart muscle, which in turn damages the heart tissue and prevents it from getting oxygen to other tissues. In addition, the body responds to the virus by creating inflammation, which is usually a appropriate reaction when it is fighting a virus. In some people with COVID-19, however, the inflammation seems to go into overdrive.  Too much inflammation  may further damage the heart or disrupt the electrical signals that help it to beat properly, which can reduce its pumping ability or lead to abnormal heart rhythms, called  arrhythmia, or make an existing arrhythmia worse. In children and teens, a high level of inflammation is called multisystem inflammatory syndrome in children (MIS-C), and it can particularly affect the heart. The virus may also affect heart cells. Researchers are working to understand if and how much this  contributes to the heart damage  seen in people with COVID-19. Some people who are seriously ill with COVID-19 form many small blood clots throughout the body including in the heart, which can also cause damage. Researchers think that  too much inflammation  may be causing the clots to form.  This inflammation is contributed by the sudden Cytokine Strorm that overwhelms the lungs and the respiratory system. Some chronic health conditions may affect how COVID-19 affects your heart. These include:

• Cardiomyopathy
• Coronary artery disease
• Diabetes
• Heart failure
• High blood pressure
• Obesity
• Stroke
• Vasculitis

source: https://www.nhlbi.nih.gov/coronavirus/heart