Histiocytoid cardiomyopathy and sudden death

Orthotopic heart transplantation in a child with histiocytoid cardiomyopathy

“…This makes it less clear that the dysrhythmia was related to a lesion-specific abnormality of the conduction system, as has been postulated in several reports. 2,4,7 It is also of interest to note that the child did manifest preexcitation on her baseline electrocardiogram, which was also found in previously reported cases. 8,9 Histiocytoid cardiomyopathy has been reported to be associated with multiple extracardiac complications, including central nervous system (CNS) abnormalities, renal and ovarian cysts, involvement of exocrine and endocrine glands as well as laryngeal web or cleft palate.…”

“…9,11 Studies focusing on common histologic features have demonstrated distinct findings of conduction system involvement with abnormal cells that are thought to be derived from conduction tissue, suggesting a tumor-like transformation of Purkinje cells. 2,4,7 There have also been studies suggesting a component of mitochondrial abnormalities as being central to histiocytic cardiomyopathy. Ultrastructural investigations often report a marked increase in abnormal mitochondria in affected cardiac tissue.…”

Histiocytoid Cardiomyopathy: A Mitochondrial Disorder

“…1 Aggregates of these cells may form atrioventricular and nodo-ventricular connections, possibly responsible for the arrhythmias frequently found in HICMP. 15 Contrary to previous speculations 3 , mitochondrial cardiomyopathy should not be differentiated from HICMP, as histological features attributed only to the one also occur in the other.…”

“…3 Granular histiocytoid cells may also be found within the cardiac conduction system with encasement and partial replacement of the bundle of His. 1,15 The abnormal Short Communication continued cells appear to resemble transformed cardiomyocytes, which possess some features of cardiac conduction system fibers. 1 Aggregates of these cells may form atrioventricular and nodo-ventricular connections, possibly responsible for the arrhythmias frequently found in HICMP.…”

Orthotopic heart transplantation in two infants with histiocytoid cardiomyopathy and left ventricular non‐compaction

“…Females are disproportionately affected. The majority of patients present with life‐threatening arrhythmias, believed to be a result of aggregates of abnormal myocytes within the conduction system . To date, there are <100 cases reported in the literature .…”