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.