Arrhythmia as the only presentation form of myocarditis

Background. Ventricular arrhythmias occur in some patients as the only clinical sign of myocarditis; still it is not included as an etiological probability. The complexity of its clinical characterization does not allow an appropriate treatment.
Aim.To analyze clinical evolution and treatment in those patients with arrhythmia as the only clinical manifestation of myocarditis.
Materials and method. Descriptive, observational, transversal, retrospective study, enrolling nineteen patients diagnosed with myocarditis, attended in our institution within the period 2000-2009. Seven patients (35%) who presented ventricular arrhythmia as the only clinical manifestation were selected. Their mean age was 18 ± 7 years old, five men and two women. All of them underwent endomyocardial biopsy, resulting positive for myocarditis. Clinical histories were analyzed in order to examine arrhythmia type, ventricular function, response to received treatment, and clinical long and short-term evolution. Statistical analysis was performed with statistical program InfoStat/Profesional version 2009p.
Results. All patients presented frequent ventricular extrasystoles; 3 (43%) non sustained ventricular tachycardia; 4 (57%) sustained ventricular tachycardia, and 1 of these patients had ventricular fibrillation. Ventricular function was normal in all patients (ejection fraction 62 ± 8,08%). Six patients (86%) received immunosupressors (corticoids y azatioprin), of which 5 (72%) evolved with isolated ventricular extrasystoles. Only one patient continued with sustained ventricular tachycardia, requiring defibrillator implantation and radiofrequency ablation. There were no deaths in a follow up of 6 ± 3 years.
Conclusions. Immunosuppressive therapy allowed reducing inflammation and controlling arrhythmias. Patients showed a good short and long term evolution.

Keywords: Myocarditis; Ventricular arrhythmia; Endomyocardial biopsy; Immunosuppressive therapy