RESUMO
Objective To measure the sizes of patent ductus arteriosus (PDA) by echocardiography,compare the results with those by X-ray angiography(XA),to analysis the correlation of measurements between echocardiography and XA,to explore the value of echocardiography on screening the size of PDA suitable for transcatheter occlusion.Methods One hundred and forty-one participants was included.The parameters of PDA including the length of PDA(PDAL),the aortic side diameter (PDADao) and the pulmonary side diameter of PDA(PDADpa) were measured from the parasternal great artery short-axis view (PSSA) and the suprasternal descending aorta long-axis view(SSLA) of echocardiography and left lateral projection of XA,and the other parameters such as the left ventriclular end-diastolic diameter index (LVEDDI),the main pulmonary artery diameter index(MPADI),the pressure drop of PDA shunt (△P) and the pulmonary artery systolic pressure index(PASPI) were measured by echocardiography.The sizes of PDA from PSSA,SSLA and XA were compared,and the correlations of the sizes of PDA between echocardiography and XA,the correlations between the other parameters by echocardiography and the PDADpa index(PDADIpa) by XA(PDADIpa-XA) and PSSA(PDADIpa-PSSA) were analyzed.Results ①The difference of the sizes of PDA:Between PSSA and SSLA had difference on mersurement of PDA(all P ＜ 0.05),except SSLA had no difference on measurement of PDADao with XA (P ＞0.05),others echocardiography parameters all had difference on measurement of PDA with XA (all P ＜ 0.05).②Correlation:Both PSSA and SSLA had positive correlations with XA (all P ＜0.01).And among these parameters,PDAL by SSLA,PDADao by SSLA and PDADpa by PSSA had better correlations with XA (r =0.92,0.87 and 0.91,respectively,all P ＜0.01).LVEDDI,MPADI and PASPI had positive correlations with PDADIpa (all P ＜0.01),the LVEDDI and MPADI had better correlations with PDADIpa-PSSA(r =0.76,0.72,all P ＜0.01),but the PASPI had a better correlation with PDADIpa-XA(r =0.70,P ＜0.01).PASP had a negative correlation with △P (r =-0.79,P ＜0.01).Conclusions There was difference between the sizes of PDA at different echocardiographic views,PDADpa by PSSA and the PDAL and the PDADao by the SSLA were more close to those parameters by XA.Multiplane views of echocardiography can evaluate all the more accurately the size of PDA and play an important role in guiding transcatheter occlusion of PDA.
RESUMO
AIM: To evaluate the effect of captopril on action potential duration and outward delayed rectification potassium current (Ik). METHODS: Action potentials were recorded using a conventional glass microelectrode filled with 3 mol/L KCl solution. Membrane patch clamp whole cell recording technique was used to investigate the Ik current maximum in the holding potential - 50 mV, lasting time 100 ms, command potential + 40 mV. RESULTS: The action potential duration of 30%, 50% repolarization (APD30, APD50) and ERP were significantly prolonged, but APD90 wasn' t prolonged significantly when captopril group compared with ischemic group. The amplitude of Ik increased significantly in ischemic group, but significantly decreased in captopril group and in captopril + ischemic group. The shapes of current - voltage relationship were unchanged among groups, but significantly upward in ischemic group and downward in captopril and captopril + ischemic group. CONCLUSION:Captopril exerts electrophysiologic action due to decreasing delay outward rectification potassium current and prolonging action potential duration of APD30, APD50 and ERP.