Histiocytoid cardiomyopathy is a rare life-threatening pediatric condition characterized by incessant ventricular tachyarrhythmia, dilated cardiomyopathy but also sudden cardiac death in over 20% of cases [1Ferrans V.J., et al. Infantile cardiomyopathy with histiocytoid change in cardiac muscle cells. Report of six patients Circulation 1976 ;  53 (4) : 708-719 [cross-ref]

Cliquez ici pour aller à la section Références]. Management is challenging and aggressive therapy as catheter ablation [2Hirano Y., et al. Successful catheter ablation of premature ventricular contractions triggering torsade de pointes in a small infant with histiocytoid cardiomyopathy: a case report Eur Heart J Case Rep 2019 ;  3 (2) : ytz091

Cliquez ici pour aller à la section Références, 3Abe Y., et al. Successful control of life-threatening polymorphic ventricular tachycardia by radiofrequency catheter ablation in an infant Heart Vessels 2014 ;  29 (3) : 422-426 [cross-ref]

Cliquez ici pour aller à la section Références], surgical resection [4Garson, et al. Incessant ventricular tachycardia in infants: myocardial hamartomas and surgical cure J Am Coll Cardiol 1987 ;  10 (3) : 619-626 [cross-ref]

Cliquez ici pour aller à la section Références] and even heart transplantation is reported in the literature [5Zangwill S.D., et al. Orthotopic heart transplantation in a child with histiocytoid cardiomyopathy J Heart Lung Transplant 2004 ;  23 (7) : 902-904 [cross-ref]

Cliquez ici pour aller à la section Références].

Over the last decade, 4 patients were referred to our institution for incessant ventricular arrythmia consistent with histiocytoid cardiomyopathy (HC) diagnosis. We retrospectively reviewed clinical data in order to highlight the management and document natural history.

Mean patient age at diagnosis was 7months [1.5–16], 3 were girls. Mean weight at diagnosis was 6.65kg [4.8–8.2]. Initial clinical presentation was incessant rapid ventricular tachycardia with right bundle branch block pattern (Fig. 1) associated with dilated cardiomyopathy in 3, 1 presented with resuscitated sudden cardiac arrest (SCA). Despite association of antiarrhythmic drugs including amiodarone, hemodynamic deterioration required intubation for mechanical ventilatory support in 3 and extracorporeal membrane assistance (ECMO) in 2 patients. The patient diagnosed after SCA have implanted with a cardioverter defibrillator (ICD) at 4months old (Fig. 2). The first patient of this case series diagnosed 10years ago, for who ECMO was not initiated, died of terminal cardiac failure despite rate control. Arrythmia burden decreased for the 3 others patients, allowing to slowly tapped down medication.

HC is known to be a rare severe condition affecting mostly girls under 2years old. Initial management can be dreadful. Still, aggressive therapy such as ECMO and ICD can allow to overcome the acute phase. Based on this small case series and report in the literature [6Villain, et al. Incessant idiopathic ventricular tachycardia in infants Arch Mal Coeur Vaiss 1990 ;  85 (5) : 665-671

Cliquez ici pour aller à la section Références], secondary natural history seams favorable.