Two clinical ablation protocols, 2C3L and stepwise, have been routinely used in our group to treat atrial fibrillation （AF）, but with a less than 60% long-term arrhythmia-free outcome achieved in patients. The goal ...Two clinical ablation protocols, 2C3L and stepwise, have been routinely used in our group to treat atrial fibrillation （AF）, but with a less than 60% long-term arrhythmia-free outcome achieved in patients. The goal of this study was to examine the underlying mechanism of low success in clinical outcome. MRI images from one patient were used to reconstruct a human atrial anatomical model, and fibrotic tissue was manually added to represent the arrhythmia substrate. AF was induced with standard protocols used in clinical practice. 2C3L and stepwise were then used to test the efficacy of arrhythmia termination in our model. The results showed that re-entries induced in our model could not be terminated by using either 2C3L or the stepwise protocol. Although some of the induced re-entries were terminated, others emerged in new areas. Ablation using only the 2C3L or stepwise method was not sufficient to terminate all re-entries in our model, which may partially explain the poor long-term arrhythmiafree outcomes in clinical practice. Our findings also suggest that computational heart modelling is an important tool to assist in the establishment of optimal ablation strategies.展开更多
In order to better understand biatrial conduction,investigate various conduction pathways,and compare the differences between isotropic and anisotropic conductions in human atria,we present a simulation study of biatr...In order to better understand biatrial conduction,investigate various conduction pathways,and compare the differences between isotropic and anisotropic conductions in human atria,we present a simulation study of biatrial conduction with known/assumed conduction pathways using a recently developed human atrial model.In addition to known pathways:(1) Bachmann's bundle(BB),(2) limbus of fossa ovalis(LFO),and(3) coronary sinus(CS),we also hypothesize that there exist two fast conduction bundles that connect the crista terminalis(CT),LFO,and CS.Our simulation demonstrates that use of these fast conduction bundles results in a conduction pattern consistent with experimental data.The comparison of isotropic and anisotropoic conductions in the BB case showed that the atrial working muscles had small effect on conduction time and conduction speed,although the conductivities assigned in anisotropic conduction were two to four times higher than the isotropic conduction.In conclusion,we suggest that the hypothesized intercaval bundles play a significant role in the biatrial conduction and that myofiber orientation has larger effects on the conduction system than the atrial working muscles.This study presents readers with new insights into human atrial conduction.展开更多
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
基金The work was supported by the CAMS Fund of the Nonprofit Central Research Institutes （No. 2016ZX330015）, National Natural Science Foundation of China （No. 11421202） and the 111 Project （No. B13003）.
文摘Two clinical ablation protocols, 2C3L and stepwise, have been routinely used in our group to treat atrial fibrillation （AF）, but with a less than 60% long-term arrhythmia-free outcome achieved in patients. The goal of this study was to examine the underlying mechanism of low success in clinical outcome. MRI images from one patient were used to reconstruct a human atrial anatomical model, and fibrotic tissue was manually added to represent the arrhythmia substrate. AF was induced with standard protocols used in clinical practice. 2C3L and stepwise were then used to test the efficacy of arrhythmia termination in our model. The results showed that re-entries induced in our model could not be terminated by using either 2C3L or the stepwise protocol. Although some of the induced re-entries were terminated, others emerged in new areas. Ablation using only the 2C3L or stepwise method was not sufficient to terminate all re-entries in our model, which may partially explain the poor long-term arrhythmiafree outcomes in clinical practice. Our findings also suggest that computational heart modelling is an important tool to assist in the establishment of optimal ablation strategies.
基金Project supported by the National Basic Research Program (973) of China (No. 2007CB512100)the National High-Tech R & D Program (863) of China (No. 2006AA02Z307)+1 种基金the National Natural Science Foundation of China (Nos. 81171421 and 61101046)the Zhejiang Provincial Natural Science Foundation of China (No. Z1080300)
文摘In order to better understand biatrial conduction,investigate various conduction pathways,and compare the differences between isotropic and anisotropic conductions in human atria,we present a simulation study of biatrial conduction with known/assumed conduction pathways using a recently developed human atrial model.In addition to known pathways:(1) Bachmann's bundle(BB),(2) limbus of fossa ovalis(LFO),and(3) coronary sinus(CS),we also hypothesize that there exist two fast conduction bundles that connect the crista terminalis(CT),LFO,and CS.Our simulation demonstrates that use of these fast conduction bundles results in a conduction pattern consistent with experimental data.The comparison of isotropic and anisotropoic conductions in the BB case showed that the atrial working muscles had small effect on conduction time and conduction speed,although the conductivities assigned in anisotropic conduction were two to four times higher than the isotropic conduction.In conclusion,we suggest that the hypothesized intercaval bundles play a significant role in the biatrial conduction and that myofiber orientation has larger effects on the conduction system than the atrial working muscles.This study presents readers with new insights into human atrial conduction.
基金Project supported by the National R&D Program for Major Research Instruments of China(No.61527811)the National Natural Science Foundation of China(No.61701435)the Zhejiang Provincial Natural Science Foundation of China(No.LY17H180003)
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.
