Fulminant eosinophilic myocarditis and refractory ventricular arrhythmias requiring mechanical circulatory support: a case report.

BACKGROUND

Fulminant eosinophilic myocarditis (EM) is a rare and often fatal condition that may present atypically and be complicated by ventricular arrhythmias. Treatment involves high-dose corticosteroids to suppress eosinophilia, as well as increasing use of mepolizumab, an anti-interleukin-5 antibody with evidence for long-term efficacy and safety.

CASE SUMMARY

A 38-year-old woman presented to the emergency department with neck pain and fatigue, and after extensive investigation was diagnosed with EM secondary to idiopathic hypereosinophilic syndrome. The patient was treated with methylprednisolone for eosinophil suppression and warfarin due to the presence of biventricular apical thrombi. Despite previously stable haemodynamics, the patient had a cardiac arrest due to ventricular fibrillation on Day 11 of hospitalization, requiring 30 min of cardiopulmonary resuscitation and commencement of veno-arterial extracorporeal membrane oxygenation support due to refractory ventricular arrhythmias. The patient was urgently listed for heart transplant but a suitable match was not identified, and she was weaned to pharmacologic support on Day 34. The patient survived with minimal sequelae and has returned to full-time work. She remains on mepolizumab as a steroid-sparing agent, therapeutic anti-coagulation, and heart failure therapy.

DISCUSSION

This report describes an atypical presentation of fulminant EM requiring weeks of mechanical circulatory support due to refractory arrhythmia rather than heart failure. The case also highlighted the benefits of non-invasive cardiac magnetic resonance imaging in both diagnosis and prognostication of EM, as well as the need to maintain a high index of suspicion for this rare disease.