Background Understanding the interaction between the mitral valve(MV)and the left ventricle(LV)is very important in assessing cardiac pump function,especially when the MV is dysfunctional.Such dysfunction is a major m...Background Understanding the interaction between the mitral valve(MV)and the left ventricle(LV)is very important in assessing cardiac pump function,especially when the MV is dysfunctional.Such dysfunction is a major medical problem owing to the essential role of the MV in cardiac pump function.Computational modelling can provide new approaches to gain insight into the functions of the MV and LV.Methods In this study,a previously developed LV-MV model was used to study cardiac dynamics of MV leaflets under normal and pathological conditions,including hypertrophic cardiomyopathy(HOCM)and calcification of the valve.The coupled LV-MV model was implemented using a hybrid immersed boundary/finite element method to enable assessment of MV haemodynamic performance.Constitutive parameters of the HOCM and calcified valves were inversely determined from published experimental data.The LV compensation mechanism was further studied in the case of the calcified MV.Results Our results showed that MV dynamics and LV pump function could be greatly affected by MV pathology.For example,the HOCM case showed bulged MV leaflets at the systole owing to low stiffness,and the calcified MV was associated with impaired diastolic filling and much-reduced stroke volume.We further demonstrated that either increasing the LV filling pressure or increasing myocardial contractility could enable a calcified valve to achieve near-normal pump function.Conclusion The modelling approach developed in this study may deepen our understanding of the interactions between the MV and the LV and help in risk stratification of heart valve disease and in silico treatment planning by exploring intrinsic compensation mechanisms.展开更多
目的研究合并巨大左心室的二尖瓣、主动脉瓣关闭不全患者行外科手术治疗后的中远期生存及心脏结构和功能变化。方法自2000年1月-2012年12月,本院完成合并巨大左心室的二尖瓣、主动脉瓣关闭不全手术共计41例,其中男性35例,女性6例,年龄22...目的研究合并巨大左心室的二尖瓣、主动脉瓣关闭不全患者行外科手术治疗后的中远期生存及心脏结构和功能变化。方法自2000年1月-2012年12月,本院完成合并巨大左心室的二尖瓣、主动脉瓣关闭不全手术共计41例,其中男性35例,女性6例,年龄22~74（46.0±12.9）岁。术前心功能分级：纽约心脏病协会（New York Heart Association,NYHA）分级Ⅰ级2例,NYHAⅡ级7例,NYHAⅢ级23例,NYHAⅣ级9例。病程0.5~40（17.6±12.1）年。超声心动图示左心室舒张末期内径（left ventricular end diastolic diameter,LVEDD）为65.0~99.0（75.9±9.2）mm,左心室收缩末期内径（left ventricular end systolic diameter,LVESD）为40.0~76.0（52.1±10.2）mm,射血分数（ejection fraction,EF）为23.0%~70.0%（51.1±10.9）%。结果 41例中,围术期死亡1例（2.43%）,与术前相比,术后2周心脏超声示左心室舒张末期内径减小为（60.8±9.9）mm（P〈0.05）。至2014年12月,32例（80%）得到随访,随访时间23~180（95.9±47.3）个月,存活30例（93.75%）,5例心功能Ⅰ级,19例心功能Ⅱ级,4例心脏功能Ⅲ级,2例心功能Ⅳ级。随访期间死亡2例（6.7%）,失访8例（20%）。因心脏原因死亡者1例,为慢性心功能不全。非心脏原因死亡者为脑卒中。存活患者LVEDD进一步减小,达（52.8±8.7）mm,与术后围术期LVEDD相比有明显缩小（P〈0.05）。结论对于合并巨大左心室的二尖瓣、主动脉瓣关闭不全患者,外科手术可改善左心室功能并使左心室进一步缩小。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11871399,12271440)the UK EPSRC(Grant Nos.EP/S030875,EP/S014284/1,EP/S020950/1,EP/R511705/1,and EP/T017899/1).
文摘Background Understanding the interaction between the mitral valve(MV)and the left ventricle(LV)is very important in assessing cardiac pump function,especially when the MV is dysfunctional.Such dysfunction is a major medical problem owing to the essential role of the MV in cardiac pump function.Computational modelling can provide new approaches to gain insight into the functions of the MV and LV.Methods In this study,a previously developed LV-MV model was used to study cardiac dynamics of MV leaflets under normal and pathological conditions,including hypertrophic cardiomyopathy(HOCM)and calcification of the valve.The coupled LV-MV model was implemented using a hybrid immersed boundary/finite element method to enable assessment of MV haemodynamic performance.Constitutive parameters of the HOCM and calcified valves were inversely determined from published experimental data.The LV compensation mechanism was further studied in the case of the calcified MV.Results Our results showed that MV dynamics and LV pump function could be greatly affected by MV pathology.For example,the HOCM case showed bulged MV leaflets at the systole owing to low stiffness,and the calcified MV was associated with impaired diastolic filling and much-reduced stroke volume.We further demonstrated that either increasing the LV filling pressure or increasing myocardial contractility could enable a calcified valve to achieve near-normal pump function.Conclusion The modelling approach developed in this study may deepen our understanding of the interactions between the MV and the LV and help in risk stratification of heart valve disease and in silico treatment planning by exploring intrinsic compensation mechanisms.
文摘目的研究合并巨大左心室的二尖瓣、主动脉瓣关闭不全患者行外科手术治疗后的中远期生存及心脏结构和功能变化。方法自2000年1月-2012年12月,本院完成合并巨大左心室的二尖瓣、主动脉瓣关闭不全手术共计41例,其中男性35例,女性6例,年龄22~74（46.0±12.9）岁。术前心功能分级：纽约心脏病协会（New York Heart Association,NYHA）分级Ⅰ级2例,NYHAⅡ级7例,NYHAⅢ级23例,NYHAⅣ级9例。病程0.5~40（17.6±12.1）年。超声心动图示左心室舒张末期内径（left ventricular end diastolic diameter,LVEDD）为65.0~99.0（75.9±9.2）mm,左心室收缩末期内径（left ventricular end systolic diameter,LVESD）为40.0~76.0（52.1±10.2）mm,射血分数（ejection fraction,EF）为23.0%~70.0%（51.1±10.9）%。结果 41例中,围术期死亡1例（2.43%）,与术前相比,术后2周心脏超声示左心室舒张末期内径减小为（60.8±9.9）mm（P〈0.05）。至2014年12月,32例（80%）得到随访,随访时间23~180（95.9±47.3）个月,存活30例（93.75%）,5例心功能Ⅰ级,19例心功能Ⅱ级,4例心脏功能Ⅲ级,2例心功能Ⅳ级。随访期间死亡2例（6.7%）,失访8例（20%）。因心脏原因死亡者1例,为慢性心功能不全。非心脏原因死亡者为脑卒中。存活患者LVEDD进一步减小,达（52.8±8.7）mm,与术后围术期LVEDD相比有明显缩小（P〈0.05）。结论对于合并巨大左心室的二尖瓣、主动脉瓣关闭不全患者,外科手术可改善左心室功能并使左心室进一步缩小。
