Hypersensitivity myocarditis complicating hypertrophic cardiomyopathy heart

The present report describes a case of eosinophilic myocarditis complicating hypertrophic cardiomyopathy. The 47-year-old female patient, known to have hypertrophic cardiomyopathy, was admitted with biventricular failure and managed aggressively with dobutamine infusion and other drugs while being assessed for heart transplantation. On transthoracic echocardiogram, she had moderate left ventricular dysfunction with regional variability and moderate mitral regurgitation. The recipient's heart showed the features of apical hypertrophic cardiomyopathy and myocarditis with abundant eosinophils. Myocarditis is rare and eosinophilic myocarditis is rarer. It is likely that the hypersensitivity (eosinophilic) myocarditis was related to dobutamine infusion therapy. Eosinophilic myocarditis has been reported with an incidence of 2.4% to 7.2% in explanted hearts and may be related to multidrug therapy.