Dilated cardiomyopathy and myocarditis in Kenya: an endomyocardial biopsy study

We have studied, by light and electron microscopy, left ventricular endomyocardial biopsy specimens from 18 African patients (14 men) with idiopathic dilated cardiomyopathy in Nairobi. Nine patients (50%) had evidence of healing myocarditis, that is the presence of a mild inflammatory cell infiltration within the myocardium. Interstitial fibrosis was prominent in five patients (28%) and in all 18 specimens there were hypertrophied muscle fibres. Therefore, half of the patients with idiopathic dilated cardiomyopathy had histological signs of a previous myocarditis. There was no serological evidence of a previous or recent coxsackie infection or any other common viral infections. It seems probable that the myocarditis was due to an inappropriate immunological reaction to myocardial muscle.