ABSTRACT
Objective To observe the perfusion changes of porcine chronic ischemic myocardium before and after gene transfer by myocardial contrast. Methods Ten normal pigs were divided into two groups: groupⅠfor gene transfer(6 pigs) and groupⅡ for control(4 pigs). Myocardial contrasts were performed respectively in basic status, 4 weeks after an Ameroid constrictor was placed around the proximal left circumflex artery (LCX) and another 4 weeks after the replication deficient recombinant adenovirus coding for the vascular endothelial growth factors (Ad. VEGF)was administrated into the regional ischemic myocardium in groupⅠ, and the phosphate buffer(PB) was administrated into similar situs in groupⅡ. The perfusion of above mentioned different blood supply myocardium was observed with HP Sonos 5500 and S4 transducer by myocardial contrast. Results The normal left ventricular myocardial wall was uniformly thick and its perfusion was bright and well filling. The chronic ischemic myocardium was thinned and its echo showed the contrast defect. The echo of the myocardium for gene transfer returned to good, but the echo of the control group remained bad including some bright bits and pieces. Conclusions The blood supply of the porcine chronic ischemic myocardium was ameliorated by gene transfer. The perfusion characters of the different blood supply myocardium can objectively reflect the blood supply status of the myocardium.
ABSTRACT
Objective: To establish porcine chronic ischemic myocardium model and to evaluate ultrasonic integrated backscatter(IBS) and Doppler tissue imaging(DTI) in detecting this model. Methods: An Ameroid constrictor was placed around the porcine proximal left circumflex artery. The calibrated average image intensity (%AⅡ), cyclic variation of IBS (CVIB), the subendo-epicardical gradient index (TGI) and the spectrum of left ventricular papillary muscle level short axis view (LVPM-SAM) and apical four chamber view (AP-4CV) were measured at normal state, 2 w, 4 w, 6 w and 8 w after Ameroid placement. Results: Normal %AⅡ, CVIB and TGI were 2.29?0.32,(9.69?2.22)dB and 0.22? 0.08 respectively. After Ameroid placement, the %AII increased gradually, the CVIB decreased gradually, and the decrease was higher in subepicardium than that in subendocardium. The most obvious decrease of TGI occurred from 2 w to 4 w after Ameroid placement and became zero at 8 w(P
ABSTRACT
Objective To investigate the value of Doppl er tissue imaging (DTI) in detecting chronic ischemic myocardium before and after gene transfer. Methods An Ameroid constrictor was placed around the left circumflex artery of each open-chest pig. After 4 weeks, groupⅠandⅡwere intramyocardially administrated recombinant adenovirus coding for the vascular endothelial growth factors(Ad.VEGF-B) or phosphate buffer(PB). After 4 weeks, their hearts were removed for pathological investigation. Color M-mode, two-dimensional and spectrum DTI of lateral-posterior wall before operation, 2 weeks and 4 weeks after Ameroid placement, 2 weeks and 4 weeks after administration were studied. Results Color of normal myocardium was bright, filling and distinct stratified, and of ischemic myocardium faint, local lost and cloudy stratified. After gene transfer, color filling became better and stratification distinct. Normal V S of apical four chamber view (AP-4CV) was greater than that of left ventricular papillary muscle level short axis view (LVPM-SAM)(P
ABSTRACT
It has been reported that angiogenic growth factors may be useful in the treatment of ischemic heart disease. In our experiment a recombinant deficient adenovirus vector coding for aFGF was intramyocardially administrated into swines with chronic ischemic myocardium to investigate its effect on the improvement of myocardial function. In the present study, experimental minipigs underwent thoracotomy and placement of an Ameroid constrictor on the left circumflex branch coronary artery. Four weeks later, Ad.aFGF( n =7), Ad.Null( n =5) or PBS( n =6), was administrated directly into the myocardium at 10 sites in the circumflex branch distribution area (10 9 pfu or 100?l). Another four weeks later, cardiac function was examined by echocardiography and the results showed significant improvement of myocardial function in Ad.aFGF animals compared with Ad.Null and PBS animals. So such a strategy of gene therapy can be used in patients with ischemic heart disease.
ABSTRACT
Objective To investigate integrated backscatter (IBS) combining with dobutamine stress in detecting chronic ischemic myocardium before and after gene transfer.Methods An Ameroid constrictor was placed around the left circumflex artery of each open chest pig.After 4 weeks,groupⅠandⅡwere intramyocardially injected recombinant adenovirus coding for the vascular endothelial growth factors or phosptat buffer.After another 4 weeks,pathological investigation of their hearts were performed.The calibrated average image intensity (%AII),cyclic variation of integrated backscatter (CVIB) and the subendo epicardical gradient index (TGI) of lateral posterior wall in basic or 10 ?g?kg -1 ?min -1 dobutamine stress state at normal state,2 weeks and 4 weeks after Ameroid placement,2 weeks and 4 weeks after injection were measured.Results During dobutamine stress,CVIB of control group at normal state and 2 weeks,4 weeks after placing Ameroid increased significantly(P 0.05 ).The TGI increased significantly in normal state and at 2 weeks (P