Development of dilated cardiomyopathy with a long latent period followed by viral fulminant myocarditis: A case report

BACKGROUND: The clinical course of acute myocarditis ranges from the occurrence of a few symptoms to the development of fatal fulminant myocarditis. Specifically, fulminant myocarditis causes clinical deterioration very rapidly and aggressively. The long-term prognosis of myocarditis is varied, and it fully recovers without leaving any special complications. However, even after recovery, heart failure may occur and eventually progress to dilated cardiomyopathy (DCM), which causes serious left ventricular dysfunction. In the case of follow-up observation, no clear guidelines have been established. CASE SUMMARY: We report the case of a 21-year-old woman who presented with dyspnea. She became hemodynamically unstable and showed sustained fatal arrhythmias with decreased heart function. She was clinically diagnosed with fulminant myocarditis based on her echocardiogram and cardiac magnetic resonance results. After 2 d, she was readmitted to the emergency department under cardiopulmonary resuscitation and received mechanical ventilation and extracorporeal membrane oxygenation. An implantable cardioverter defibrillator was inserted for secondary prevention. She recovered and was discharged. Prior to being hospitalized for sudden cardiac function decline and arrhythmia, she had been well for 7 years without any complications. She was finally diagnosed with dilated cardiomyopathy. CONCLUSION: DCM may develop unexpectedly in patients who have been cured of acute fulminant myocarditis and have been stable with a long period of remission. Therefore, they should be carefully and regularly observed clinically throughout long-term follow-up.