OBJECTIVETo investigate the histopathological features of primary restrictive cardiomyopathy (PRCM).

METHODSNine extransplanted hearts from heart transplantation recipients were examined. Gross and histopathological findings were observed, photographed and final pathological diagnosis was compared to clinical diagnosis. The myocardial ultrastructure changes were determined using transmission electron microscopy.

RESULTSThe hallmark pathologic feature of PRCM was distinguished by myocardial cell degeneration and hyperplastic collagen fibrils around the myocardial cells.Fibrosis was severer in left ventricle free wall than in ventricular septum and right ventricle. The degree of myocardial cell degeneration and poloidal disorder were severer in patients with reduced ejection fraction (EF) than in patients with preserved EF. Transmission electron microscope evidenced severe interstitial fibrosis, myofibrillar changes of sarcomere structure, abnormalities both on intercalated disc number and distribution.

CONCLUSIONSPRCM is characterized by hyperplastic collagen fibrils around the cardiomyocytes. Fibrosis is severer in left ventricle than in right ventricle. Sarcomere dysplasia is the main cause of PRCM, and ultrastructural examination is helpful for PRCM diagnosis.

Cardiomyopathy, Restrictive ; surgery ; Fibrosis ; Heart Transplantation ; Heart Ventricles ; Humans ; Myocardium ; pathology ; Myocytes, Cardiac ; Sarcomeres

OBJECTIVETo investigate the association between clinical and histopathological features in patients with left ventricular non-compaction cardiomyopathy (LVNC).

METHODSHistopathological examinations were made on 11 LVNC recipient hearts from June 2004 to June 2014 in Fuwai Hospital, myocardial ultrastructure changes were detected using transmission electron microscopy. Association between clinical and pathological features were analyzed.

RESULTSPatients were (24 ± 11) years old. There were 6 patients with mucus matrix LVNC, 3 patients with fibrous fatty infiltration, and 2 patients with cardiomyocytes proliferation. The gross morphological changes of LVNC hearts were characterized by numerous and prominent trabeculations with deep intratrabecular recesses in left ventricular myocardium. Ratios of the thicker noncompacted endocardial layer (N) and thin epicardial compacted layer (C) (N/C ratio) were ≥ 2.0, and the most serious lesions were located in the left ventricular apex, and followed by the left ventricular free wall. Histological microscopic examinations evidenced numerous matrix-like material and immature cardiomyocytes on endocardial tissue. Transmission electron microscopy revealed mitochondrial abnormalities on morphology, number, and distribution, underdeveloped cardiomyocytes and anomalies of intercalated disc structure, increased deposition of extracellular matrix-like substance and perinuclear glycogen. Pathological changes on cytoplasmic matrix and intercalated disc were present in all three tissue types of LVNC in this cohort and mitochondria hyperplasia was detected in patients with fibrous fatty infiltration. Heart weight ≥ 350 g is often associated with increased number of mitochondria. Increased cytoplasmic matrix was often detected in patients with LVEF ≥ 30% while intercalated disc anomalies were often detected in patients with LVEF < 30%.

CONCLUSIONHistological changes were closely related clinical features in patients with LVNC.

Adolescent ; Adult ; Cardiomyopathies ; pathology ; Endocardium ; pathology ; Heart Ventricles ; pathology ; Humans ; Mitochondria, Heart ; pathology ; Myocardium ; pathology ; ultrastructure ; Young Adult