HEART WEIGHT AND MYOCYTE LOSS IN HUMAN IDIOPATHIC DILATED CARDIOMYOPATHY

FORNONI D; CABEZA MECKERT P; VIGLIANO CA; FAVALORO RR; LAGUENS RP

Buenos Aires

Congreso; XXVII CONGRESO NACIONAL DE CARDIOLOGIA; 2009

FEDERACION ARGENTINA DE CARDIOLOGIA

In cardiomyocytes (CM) isolated from the left ventricle (LV) of 15 explanted hearts of IDCM patients submitted to heart transplant and from 5 normal hearts the cell volume (V), number of binucleated cells (BC) and hypertetraploid nuclei (HT) were significantly higher in IDCM than in controls. V: 39.133 micrones3 ± 9.204 vs. 14.031 micrones3 ± 2.437 (p<0.001); BC: 32.5 ± 6.9% vs. 17.1 ± 3% (p<0.001) and HT: (26.3% ± 7 vs. 10% ± 3 (p<0.001). Although the number (N) of CM in the LV was lower in IDCM than in normal hearts (7×109 ± 2.3 vs. 9.01×109 ± 3), it was not statistically significant. When the hearts were separated by LV weight, <250 g (n=8) and >250 g (n=7), cell volume was similar for both groups but in the <250 g group N was lower (5.2×109 ± 1.3 vs. 8.65 × 109±2, p<0.001), and the proportion of binucleated cells (36.5 ± 7% vs. 28.4 ± 3.5%, p<0.001) and hypertetraploid nuclei (31.9 ± 3.4% vs. 17.4 ± 3.6%, p<0.001) were higher. It can be suggest that in the progression towards LVH and HF there is a change in the signaling pathways that modulate LV function. While activation of PKA is associated to beneficial effects, activation of CaMKII is associated with a severe impairment of LV function.