The most common form of acute heart disease would be caused by bacterial infections. Bacteria are capable of reproduction, which differentiates them from viruses , which have to enter a host cell and change it so it reproduces the virus. Viruses, therefore, are parasites because they have to live off a host. This is an inflamation of the endocardium. It begins with flu-like symptoms.
Treatment involves antibiotics.
Pericarditis is the inflammation of the pericardium. A common symptom is chest pain caused by breathing. Treatment involves antibiotics. Severe cases involve excessive fluid within the paricardium which restricts the myocardium. Rheumatic heart disease is caused by rheumatic fever, an allergic response to a streptoccal bacterial infection.