Chronic Congestive Heart Failure, Cardiac Stem Cell Transplantation After Myocardial Electrophysiological Properties Changes

Stem cells transplantation is emerging as a potential novel therapeutic approach for the treatment of heart failure, however, it remains unclear whether grafted stem cell-derived cells directly affect local electrophysiological properties in situ. The investigation was divided into in vitro and in vivo trial. In vitro trial, the mesenchysmal stem cells (MSCs) and skeletal myoblast cells (SMCs) were co-cultured with neo-cardiomyocytes, respectively. After seven days, troponin I and connexin43 were found in MSCs co-cultured with neo-cardiomyocytes, whereas, connexin43 was not observed in SMCs co-culture group. In vivo trial, heart failure was induced by the intravenous administration of doxorubicin in rabbit. Either autologous MSCs or SMCs were transplanted into failing hearts through the root of aorta while two balloons occluding the sinus of Valsalva. Four weeks after transplantation, electrophysiological study showed both MSCs and SMCs transplantation resulted in elongation of local activation time (AT) and enlargement of AT dispersion (ATd).In stem cells transplantation groups, significant correlation was showed between ATd and the number of stem cell-derived cells in pacing location (r=0.46, P=0.031 at SI SI pacing, and r=0.60, /*=().003 at S1S2 pacing, respectively), moreover, the local effective refractory period correlated with local quantity of stem cell-derived cells (r=0.37, P=0.028) in MSCs transplantation group. These data suggest that stem cells transplantation could result in abnormalities of electrophysiological properties, a proclivity that exacerbates the arrhythmogenic substrate in failing heart.