A case of rheumatic fever can cause the heart to inflame; whilst this inflammation can disappear it can leave permanent damage to the heart valves.
A heart valve acts like a one-way door. It makes sure that blood pumped by the heart flows in one direction. When the heart is damaged the heart valves are unable to function adequately.
Damage to the heart caused from rheumatic fever is called rheumatic heart disease, or RHD, which can lead to heart failure and sometimes the need for cardiac surgery or death.