Proliferation of iVSD cardiomyocytes analyzed via confocal microscopy.

Confocal microscopy of tissue sections using Ki67 and troponin indicate that non-cardiomyocyte cell proliferation is decreased in iVSD tissues compared to controls. (A) Representative Ki67-positive cells in normal hearts. (B) Representative Ki67-positive cells in iVSD hearts. (C) Quantification of Ki67-positive cardiomyocytes. (D) Quantification of Ki67-positive non-cardiomyocytes (iVSD group: n = 20; control group: n = 6. Data presented as means ± SD; ***p<0.001. Cardiac troponin T (red), Ki67 (green), and DAPI (blue) staining are shown. Arrow indicates proliferating cardiomyocytes and the triangle indicates non-cardiomyocytes.