The balloon pump is inserted into your aorta above the heart. It takes over some of the heart's pumping function. In rare cases, a heart transplant is required. If you have developed a dangerous arrhythmia due to the myocarditis, you may be hospitalized in order to receive frequent monitoring. Most cases of myocarditis clear up by themselves without complications.
Some people develop chronic weakness of the heart and heart failure.
The latter is a rare occurrence. Some arrhythmias may be fatal if untreated. On rare occasions, untreated myocarditis can lead to death. Again, this depends upon the underlying disease. Chagas and diphtheria are two examples of diseases which must be treated to avoid fatal consequences.