Administration of vascular endothelial growth factor adjunctive to fetal cardiomyocyte transplantation and improvement of cardiac function in the rat model.

BACKGROUND: The functional impact of cellular transplantation and the potential role of the addition of angiogenic factors for survival of engrafts remain controversial. METHODS: Vascular endothelial growth factor (VEGF) (25 ng/mL) was added to cultured fetal cardiomyocytes labeled with bromodeoxyuridine (BrDU), which was injected into the border zones of myocardial infarction 4 weeks after coronary occlusion in rat hearts. Group 1 (n = 12) received cells plus VEGF protein (100 ng), group 2 (n = 12) received cells without VEGF, group 3 (n = 10) received VEGF without cells, and group 4 (n = 12) received pure culture medium. Cardiac function was then assessed by transthoracic two-dimensional echocardiography and Langendorff perfusion system. In situ hybridization for Y chromosomes of transplanted cells, detection of BrDU-labeled cells, and platelet/endothelial cell adhesion molecule-1 (PECAM-1) staining for endothelial cells was performed. RESULTS: Echocardiography revealed smaller end-diastolic left ventricular dimensions in transplanted hearts in group 1 (0.83 +/- 0.13 cm 4 weeks after coronary occlusion before transplantation and 0.69 +/- 0.14 cm 2 months after transplantation, P < .05) and in group 2 (0.88 +/- 0.09 cm after coronary occlusion before transplantation and 0.76 +/- 0.08 cm 2 months after transplant), and increases in fractional shortening (34.2% +/- 8.53% before transplant and 45.3% +/- 10.9% after [P < .05] in group 1; 26.9% +/- 6.02% before transplant and 37.15% +/-8.08% after [P < .005] in group 2), whereas groups 3 and 4 showed a decrease in fractional shortening. Transplanted hearts developed higher pressures at rest (group 1, 96.8 +/- 20.8 mm Hg; group 2, 98.6 +/- 21.9 mm Hg) compared with controls (group 4, 70.9 +/- 25 mm Hg) (P < .05) and during inotropic stimulation (group 1, 111 +/- 19.5 mm Hg and group 2, 113.3 +/- 32.6 vs group 4, 80.7 +/- 31.6 mm Hg, P < .05). Histologic analysis demonstrated the presence of transplanted cells in border zones of infarcted host myocardium with neovascularization in all transplanted hearts. CONCLUSION: Transplantation of fetal cardiomyocytes results in improvement of left ventricular function. The addition of VEGF does not contribute to further improvement of left ventricular function and angiogenesis in the present model.

Cardioprotection by Carvedilol: antiapoptosis is independent of beta-adrenoceptor blockage in the rat heart.

BACKGROUND: Carvedilol, a beta-blocking agent with beta-blocking properties is now widely used for the treatment of congestive heart failure. In addition to its beta-adrenergic receptor blockage, antiapoptotic effects have been demonstrated in experimental animals. OBJECTIVE: The cardioprotective effects of carvedilol and its hydroxylated analogue BM-91.0228 were tested with regard to their infarct-limiting and antiapoptotic properties in an experimental infarct model in the rat heart. METHODS: Anesthetized rats were subjected to either 30 (groups 1 to 3) or 60 minutes (groups 4 to 6) of coronary artery occlusion followed by 30 minutes of reperfusion. Groups 1 and 4 served as the control; groups 2 and 5 received intravenous Carvedilol (1 mg/kg) and groups 3 and 6 received intravenous administration of BM-91.0228 (1 mg/kg), respectively, 5 minutes prior to coronary occlusion. Infarct sizes were measured by triphenyltetrazolium chloride staining. In situ visualization of apoptosis was measured by nick end labeling. RESULTS: Carvedilol reduced infarct size after 30 minutes of coronary occlusion compared to controls (8.7% +/- 2.7% versus 27.3% +/- 3.4%, P <.001), while BM-91.0228 showed no significant infarct size reduction (23.7% +/- 5.9%, NS). Neither Carvedilol (36.9% +/- 3.9%) nor BM-91.0228 (42.4% +/- 3.6%) reduced infarct size after 60 minutes of coronary occlusion compared to controls (47.7% +/- 3.9%, NS). Carvedilol reduced apoptosis after 30 minutes (4.9% +/- 1.3% versus 16.7% +/- 3.2%, P <.01) and after 60 minutes (11.7% +/- 1.8% versus 25.5% +/- 0.5%, P <.001) of coronary occlusion compared to controls. BM-91.0228 reduced apoptosis after 30 minutes (7.3% +/- 1.4% versus 16.7% +/- 3.2%, P <.01) and after 60 minutes (13.4% +/- 1.8% versus 25.5% +/- 0.5%, P <.001) of coronary occlusion compared to controls. CONCLUSION: Carvedilol is cardioprotective by preventing ischemia-perfusion-induced necrosis and apoptosis of cardiomyocytes. The antiapoptotic effects of Carvedilol are independent of its beta-adrenoceptor blocking effects, but its effects might be caused by antioxidant properties and by modulation of the signalling pathway.

Transvenous pacemaker malposition in the systemic circulation and pacemaker infection: a case report and review of the literature.

Transvenous pacemaker malposition in the systemic circulation is a rare complication of pacemaker implantation; the incidence is not well known. However, with the aid of two-dimensional echocardiography, the problem of pacemaker malposition can be identified earlier. After pacemaker insertion, an electrocardiogram and a posterior-anterior and lateral chest x-ray should be routinely performed. In difficult cases, transthoracic echocardiography and transesophageal echocardiography can be helpful for better visualization and confirmation of the malposition of the pacemaker lead(s). Pacemaker infection is another complication. A case of pacer lead malposition into the left ventricle through a sinus venosus atrial septal defect and superimposed infection is reported, and the management of endocardial lead malposition in the systemic circulation and pacemaker infection is reviewed.