The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria.The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courteman...The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria.The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courtemanche(RNC) model using the recently available experimental data of ionic currents and was further developed based on our own experimental data.A model of right atria was then built by considering the differences between right atria and left atria.The two developed models well reproduced the experimental data on action potential morphology,the rate dependence,and action potential duration restitution.They are useful for investigating the mechanisms underlying the het-erogeneity of canine regional action potentials and would help the simulation of whole heart excitation propagation and cardiac arrhythmia in the near future.展开更多
Speckle tracking imaging （STI） was employed to investigate the effect of right ventricular （RV） volume and pressure overload on left ventricular （LV） rotation and twist in 35 patients with atrial septal defect ...Speckle tracking imaging （STI） was employed to investigate the effect of right ventricular （RV） volume and pressure overload on left ventricular （LV） rotation and twist in 35 patients with atrial septal defect （ASD）, 18 of which with pulmonary hypertension, and 21 healthy subjects serving as controls. The peak rotations of 6 segments at the basal and apical short-axises and the average peak rotation and interval time of the 6 segments in the opposite direction during early systolic phase were measured respectively. LV twist versus time profile was drawn and the peak twist and time to peak twist were calculated. LV ejection fraction （EF） was measured by Biplane Simpson. Compared to ASD patients without pulmonary hypertension and healthy subjects, the peak rotations of posterior, inferior and postsept walls at the basal level were lower （P〈0.05）, and the average counterclockwise peak rotation of 6 segments at the basal level during early systolic phase was higher （P〈0.05）, and the average interval time was delayed （P〈0.05）. LV peak twist was also lower （P〈0.05）, and had a significant negative correlation with pulmonary arterial systolic pressure （r=-0.57, P=0.001）. No significant differences were found in LVEF among the three groups. It was suggested that although RV volume overload due to ASD has no significant effects on LV rotation and twist, LV peak twist is lower in ASD patients with pulmonary hypertension. Thus LV twist may serve as a new indicator of the presence of pulmonary hypertension in ASD patients.展开更多
The carduc effects of THB were studied in uolated rught and left atrual prepa-rations from guinea pigs.In spontaneously beating right atrua,TH B(1-56.3μmal/L caused brady-card ia,which was not prevented by atropine(1...The carduc effects of THB were studied in uolated rught and left atrual prepa-rations from guinea pigs.In spontaneously beating right atrua,TH B(1-56.3μmal/L caused brady-card ia,which was not prevented by atropine(1μmol/L).The time-effect curve of right atria on 4 mmul/L CaClz was markedly decreased by TIB.Tl B shifted the concentratwn-effect curve of iso to the right,and the maximum effect of Iso was clearly reduced.The PD2'was 5.32.For this reasun,the bradycard iae effect of TlI B mught be related to antogonism to Ca'+transport and non-competitme,block ofβ-adrenoceptur.Tll B pruduced negative inotropu effect.A decrease in trans membrane influz of Ca²+and inhibution of intracelluar calcium release mrght contribute to this action.展开更多
Objective To study the change of diastolic cardiac function in diabetic patients and to determine the diagnostic value of plasma brain natriuretic peptide （BNP） and atria natriuretic peptide （ANP） for diastolic he...Objective To study the change of diastolic cardiac function in diabetic patients and to determine the diagnostic value of plasma brain natriuretic peptide （BNP） and atria natriuretic peptide （ANP） for diastolic heart failure in patients with type 2 diabetes mellitus. Methods Twelve healthy subjects and seventy-one diabetic patients were included in the study. Plasma BNP and ANP were measured with immtmoradiometic assay. Results Plasma levels of BNP and ANP increased significantly with increased severity of diastolic heart dysfunction. The ratio of E/A had significant negative correlation with the plasma levels ofBNP （r=0.669,P〈0.001） and ANP （r=0.579, P〈0.01）. AUC of ANP and BNP in ROC model was 91.9% and 65.3%, respectively. Conclusions The plasma level of BNP might be a valuable predictor for differential diagnosis of diastolic cardiac function in diabetic patients.展开更多
Objectives To determine the safety and value of esophageal radiography as a means of locating transseptal puncture. Methods 486 patients who underwent transseptal puncture were randomized into two groups. An esophagus...Objectives To determine the safety and value of esophageal radiography as a means of locating transseptal puncture. Methods 486 patients who underwent transseptal puncture were randomized into two groups. An esophagus radiographic method of locating tansseptal puncture site was applied in the study group （n = 243 ） and modified-Ross locating method was used in the control group （n = 243 ）. After successful location, transseptal puncture was made. We observed the success rate and incidence complications in the 2 groups. Results Left atrium impression in the study group was clearly seen. Nonetheless in 120 cases of control group, the left atria silhouette was not clearly visualised. The success rate of locating transseptal puncture site in the study group and control group were 100% and 50. 6% respectively （ P 〈 0. 001 ）. The success rate of transseptal puncture in the study group and control group was 99. 6% and 45.7% respectively （ P 〈 0. 001 ）. There were no complications associated with puncture in the study group and pericardial tamponade occurred in 1 control patient. Conclusions The esophagus radiographic method of locating transseptal puncture site is accurate, safe and simple to perform. Transseptal puncture has a high success rate with few complications.展开更多
基金supported by the National Basic Research Program (973) of China (No.2007CB512100)the National High-Tech R & D Program (863) of China (No.2006AA02Z307)the National Natural Science Foundation of China (No.30570484)
文摘The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria.The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courtemanche(RNC) model using the recently available experimental data of ionic currents and was further developed based on our own experimental data.A model of right atria was then built by considering the differences between right atria and left atria.The two developed models well reproduced the experimental data on action potential morphology,the rate dependence,and action potential duration restitution.They are useful for investigating the mechanisms underlying the het-erogeneity of canine regional action potentials and would help the simulation of whole heart excitation propagation and cardiac arrhythmia in the near future.
文摘Speckle tracking imaging （STI） was employed to investigate the effect of right ventricular （RV） volume and pressure overload on left ventricular （LV） rotation and twist in 35 patients with atrial septal defect （ASD）, 18 of which with pulmonary hypertension, and 21 healthy subjects serving as controls. The peak rotations of 6 segments at the basal and apical short-axises and the average peak rotation and interval time of the 6 segments in the opposite direction during early systolic phase were measured respectively. LV twist versus time profile was drawn and the peak twist and time to peak twist were calculated. LV ejection fraction （EF） was measured by Biplane Simpson. Compared to ASD patients without pulmonary hypertension and healthy subjects, the peak rotations of posterior, inferior and postsept walls at the basal level were lower （P〈0.05）, and the average counterclockwise peak rotation of 6 segments at the basal level during early systolic phase was higher （P〈0.05）, and the average interval time was delayed （P〈0.05）. LV peak twist was also lower （P〈0.05）, and had a significant negative correlation with pulmonary arterial systolic pressure （r=-0.57, P=0.001）. No significant differences were found in LVEF among the three groups. It was suggested that although RV volume overload due to ASD has no significant effects on LV rotation and twist, LV peak twist is lower in ASD patients with pulmonary hypertension. Thus LV twist may serve as a new indicator of the presence of pulmonary hypertension in ASD patients.
文摘The carduc effects of THB were studied in uolated rught and left atrual prepa-rations from guinea pigs.In spontaneously beating right atrua,TH B(1-56.3μmal/L caused brady-card ia,which was not prevented by atropine(1μmol/L).The time-effect curve of right atria on 4 mmul/L CaClz was markedly decreased by TIB.Tl B shifted the concentratwn-effect curve of iso to the right,and the maximum effect of Iso was clearly reduced.The PD2'was 5.32.For this reasun,the bradycard iae effect of TlI B mught be related to antogonism to Ca'+transport and non-competitme,block ofβ-adrenoceptur.Tll B pruduced negative inotropu effect.A decrease in trans membrane influz of Ca²+and inhibution of intracelluar calcium release mrght contribute to this action.
文摘Objective To study the change of diastolic cardiac function in diabetic patients and to determine the diagnostic value of plasma brain natriuretic peptide （BNP） and atria natriuretic peptide （ANP） for diastolic heart failure in patients with type 2 diabetes mellitus. Methods Twelve healthy subjects and seventy-one diabetic patients were included in the study. Plasma BNP and ANP were measured with immtmoradiometic assay. Results Plasma levels of BNP and ANP increased significantly with increased severity of diastolic heart dysfunction. The ratio of E/A had significant negative correlation with the plasma levels ofBNP （r=0.669,P〈0.001） and ANP （r=0.579, P〈0.01）. AUC of ANP and BNP in ROC model was 91.9% and 65.3%, respectively. Conclusions The plasma level of BNP might be a valuable predictor for differential diagnosis of diastolic cardiac function in diabetic patients.
文摘Objectives To determine the safety and value of esophageal radiography as a means of locating transseptal puncture. Methods 486 patients who underwent transseptal puncture were randomized into two groups. An esophagus radiographic method of locating tansseptal puncture site was applied in the study group （n = 243 ） and modified-Ross locating method was used in the control group （n = 243 ）. After successful location, transseptal puncture was made. We observed the success rate and incidence complications in the 2 groups. Results Left atrium impression in the study group was clearly seen. Nonetheless in 120 cases of control group, the left atria silhouette was not clearly visualised. The success rate of locating transseptal puncture site in the study group and control group were 100% and 50. 6% respectively （ P 〈 0. 001 ）. The success rate of transseptal puncture in the study group and control group was 99. 6% and 45.7% respectively （ P 〈 0. 001 ）. There were no complications associated with puncture in the study group and pericardial tamponade occurred in 1 control patient. Conclusions The esophagus radiographic method of locating transseptal puncture site is accurate, safe and simple to perform. Transseptal puncture has a high success rate with few complications.
