The ability of the heart to pump around the blood in the body is impaired if you develop inflammation of the heart muscle. Sometimes fluid is collected in the lungs and in the heart sac, the membrane surrounding the heart. The disease usually heals by itself.
Here you can read about inflammations and infections in the heart.
If you have a myocardial infarction, the double membrane that is around the heart has become inflamed. In rare cases, fluid may accumulate between the membranes. Then the heart becomes more difficult to pump the blood and the blood circulation becomes worse. With treatment, inflammation can go away quickly, but sometimes it takes months or years.
Children can have three different types of infections or inflammations of the heart. All three variants are unusual. The infections are caused by viruses or bacteria, which spread to the heart. It can happen when the child has an infection elsewhere in the body or during surgery. It can also occur without knowing the cause.