Background： Mitral valve （MV） repair can now be carried out through small incisions with the use of robotic assistance. Previous reports have demonstrated the excellent clinical result of robotic MV repair for dege...Background： Mitral valve （MV） repair can now be carried out through small incisions with the use of robotic assistance. Previous reports have demonstrated the excellent clinical result of robotic MV repair for degenerative mitral regurgitation （MR）. However, there has been limited infomlation regarding tile echocardiographic follow-up of these patients. The present study was therefore to evaluate the echocardiographic follow-up outcomes after robotic MV repair in patients with MR due to degenerative disease of the MV. Methods： A retrospective analysis was undertaken using data from the echocardiographic database of our department. Between March 2007 and February 2015, 84 patients with degenerative MR underwent robotic MV repair. The repair techniques included leaflet resection in 67 patients （79.8%）, artificial chordae in 20 （23.8%）, and ring annuloplasty in 79 （94.1%）. Eighty-one （96.4%） of the 84 patients were eligible for echocardiographic follow-up assessment, and no patients were lost to follow-up. Results： At a median echocardiographic follow-up of 36.0 months （interquartile range 14.3-59.4 months）, lbur patients （4.9%） developed recurrent mild MR, and no patients had more than mild MR. Mean MR grade, leli atrial diameter （LAD）, left ventricular end-diastolic diameter （LVEDD）, and let1 ventricular ejection fraction （LVEF） were significantly decreased when compared with preoperative values. Mean MR grade decreased from 3.96 ± 0.13 to 0.17 ± 0.49 （Z- -8.456, P 〈 0.001 ）, LAD from 43.8 ± 5.9 to 35.5 ± 3.8 mm （I - 15.131, P 〈 0.001 ）, LVEDD fiom 51.0 ± 5.0 to 43.3 ± 2.2 mm （t = 14.481, P 〈 0.001 ）, and LV EF l＇rom 67.3 ± 7.0% to 63.9 ± 5.1% （t = 4.585, P 〈 0.001 ）. Conclusion： Robotic MV repair for MR due to degenerative disease is associated with a low rate of recurrent MR, and a significant improvement in MR grade, LAD, and LVEDD, but a significant decrease in LVEF at echocardiographic follow-up.展开更多
Background and Aim:It remains unknown how and where the mitral valve leaks in functional mitral regurgitation.The objective of the current study was to quantify the geometry and position of the leaflet free edges in o...Background and Aim:It remains unknown how and where the mitral valve leaks in functional mitral regurgitation.The objective of the current study was to quantify the geometry and position of the leaflet free edges in order to reveal gapping mechanism of the mitral valve,and develop a plug technique to prevent mitral regurgitation.Methods:Eight porcine mitral valves were sutured onto a dilated annulus in an in-vitro experiment to simulate valve closure at hydrostatic transmitral pressure.Eight sonocrystals were attached to the mitral valve leaflet free edges.Papillary muscles(PM)were adjusted to the normal position,and subsequently to positions of asymmetric and symmetric papillary muscle displacement.Sonocrystal positions were measured and analyzed.Results:The leaflet free edges in the central and medial regions moved medially,apically,and posteriorly from normal to asymmetric PM position.Gapping potential in the posteromedial region increased.Medial displacement of the free edges sometimes generated a gap in the anterolateral region in the asymmetric PM position.The leaflet free edges moved posteriorly and apically from the normal to symmetric PM position,and generated a dumb-bell shaped gap.Conclusions:Asymmetric PM position impairs the posteromedial coaptation region due to leaflet tenting,and compromises the anterolateral coaptation region due to medial leaflet displacement.The gaps include multiple sites along the coaptation line.Symmetric PM position impairs valve coaptation due to valve tenting only.The gap is a symmetrical dumb-bell shape.The findings are crucial for development of the plug technique to prevent mitral regurgitation.展开更多
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
In primary mitral regurgitation there are anatomic abnormalities of the mitral valve causing backward fl ow,placing a hemodynamic burden on the left ventricle.If this burden is severe and prolonged,it leads to left ve...In primary mitral regurgitation there are anatomic abnormalities of the mitral valve causing backward fl ow,placing a hemodynamic burden on the left ventricle.If this burden is severe and prolonged,it leads to left ventricular damage,heart failure,and death.The preferred therapy is restoration of mitral competence through mitral valve repair,which is safer than mitral valve replacement.When repair is performed in a timely fashion,lifespan can be returned to that of a normal individual.Triggers for timely repair include the onset of symptoms and evidence of left ventricular dysfunction as determined by ejection fraction falling toward 60%and/or end-systolic dimension increasing toward 40 mm.展开更多
Management of rheumatic mitral regurgitation in a woman contemplating pregnancy presents unique challenges for the clinician.When tasked with taking care of this type of patient,attention needs to be paid to the pati...Management of rheumatic mitral regurgitation in a woman contemplating pregnancy presents unique challenges for the clinician.When tasked with taking care of this type of patient,attention needs to be paid to the patient’s functional status to determine if symptoms are present.In addition to this clinical assessment,transthoracic echocardiography is also critical.It provides insight into the etiology of the mitral regurgitation,assesses for the presence of concomitant mitral stenosis or other valvular abnormalities,characterizes the severity of mitral regurgitation through an integrative approach and identifi es high risk findings including progressive left ventricular(LV)dilation and LV dysfunction.Surgical intervention is recommended for symptomatic patients and in asymptomatic patients with evidence of progressive LV dilation and a LV ejection fraction of less than 60%.While the presence of pulmonary hypertension and atrial fi brillation have been shown to be risk factors in degenerative mitral regurgitation,the same has not been demonstrated in rheumatic mitral valve disease.While mitral regurgitation may be reasonably well tolerated during pregnancy,symptomatic patients are at higher risk for adverse maternal and fetal outcomes,and therefore,it is recommended that mitral valve surgery be performed prior to pregnancy.Once the decision has been made to proceed to surgery,mitral repair,performed at a Heart Valve Center of Excellence is recommended if possible due to improved outcomes.Mitral valve repair is possible in>80%cases of rheumatic mitral regurgitation.If repair is not possible,replacement with either a bioprosthetic or mechanical valve are reasonable options.There are advantages and disadvantages to each approach and the choice of prosthesis should be a shared decision between the patient and her treatment team.展开更多
文摘Background： Mitral valve （MV） repair can now be carried out through small incisions with the use of robotic assistance. Previous reports have demonstrated the excellent clinical result of robotic MV repair for degenerative mitral regurgitation （MR）. However, there has been limited infomlation regarding tile echocardiographic follow-up of these patients. The present study was therefore to evaluate the echocardiographic follow-up outcomes after robotic MV repair in patients with MR due to degenerative disease of the MV. Methods： A retrospective analysis was undertaken using data from the echocardiographic database of our department. Between March 2007 and February 2015, 84 patients with degenerative MR underwent robotic MV repair. The repair techniques included leaflet resection in 67 patients （79.8%）, artificial chordae in 20 （23.8%）, and ring annuloplasty in 79 （94.1%）. Eighty-one （96.4%） of the 84 patients were eligible for echocardiographic follow-up assessment, and no patients were lost to follow-up. Results： At a median echocardiographic follow-up of 36.0 months （interquartile range 14.3-59.4 months）, lbur patients （4.9%） developed recurrent mild MR, and no patients had more than mild MR. Mean MR grade, leli atrial diameter （LAD）, left ventricular end-diastolic diameter （LVEDD）, and let1 ventricular ejection fraction （LVEF） were significantly decreased when compared with preoperative values. Mean MR grade decreased from 3.96 ± 0.13 to 0.17 ± 0.49 （Z- -8.456, P 〈 0.001 ）, LAD from 43.8 ± 5.9 to 35.5 ± 3.8 mm （I - 15.131, P 〈 0.001 ）, LVEDD fiom 51.0 ± 5.0 to 43.3 ± 2.2 mm （t = 14.481, P 〈 0.001 ）, and LV EF l＇rom 67.3 ± 7.0% to 63.9 ± 5.1% （t = 4.585, P 〈 0.001 ）. Conclusion： Robotic MV repair for MR due to degenerative disease is associated with a low rate of recurrent MR, and a significant improvement in MR grade, LAD, and LVEDD, but a significant decrease in LVEF at echocardiographic follow-up.
基金supported by the National Natural Science Foundation of China under grant#31600794.
文摘Background and Aim:It remains unknown how and where the mitral valve leaks in functional mitral regurgitation.The objective of the current study was to quantify the geometry and position of the leaflet free edges in order to reveal gapping mechanism of the mitral valve,and develop a plug technique to prevent mitral regurgitation.Methods:Eight porcine mitral valves were sutured onto a dilated annulus in an in-vitro experiment to simulate valve closure at hydrostatic transmitral pressure.Eight sonocrystals were attached to the mitral valve leaflet free edges.Papillary muscles(PM)were adjusted to the normal position,and subsequently to positions of asymmetric and symmetric papillary muscle displacement.Sonocrystal positions were measured and analyzed.Results:The leaflet free edges in the central and medial regions moved medially,apically,and posteriorly from normal to asymmetric PM position.Gapping potential in the posteromedial region increased.Medial displacement of the free edges sometimes generated a gap in the anterolateral region in the asymmetric PM position.The leaflet free edges moved posteriorly and apically from the normal to symmetric PM position,and generated a dumb-bell shaped gap.Conclusions:Asymmetric PM position impairs the posteromedial coaptation region due to leaflet tenting,and compromises the anterolateral coaptation region due to medial leaflet displacement.The gaps include multiple sites along the coaptation line.Symmetric PM position impairs valve coaptation due to valve tenting only.The gap is a symmetrical dumb-bell shape.The findings are crucial for development of the plug technique to prevent mitral regurgitation.
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In primary mitral regurgitation there are anatomic abnormalities of the mitral valve causing backward fl ow,placing a hemodynamic burden on the left ventricle.If this burden is severe and prolonged,it leads to left ventricular damage,heart failure,and death.The preferred therapy is restoration of mitral competence through mitral valve repair,which is safer than mitral valve replacement.When repair is performed in a timely fashion,lifespan can be returned to that of a normal individual.Triggers for timely repair include the onset of symptoms and evidence of left ventricular dysfunction as determined by ejection fraction falling toward 60%and/or end-systolic dimension increasing toward 40 mm.
文摘Management of rheumatic mitral regurgitation in a woman contemplating pregnancy presents unique challenges for the clinician.When tasked with taking care of this type of patient,attention needs to be paid to the patient’s functional status to determine if symptoms are present.In addition to this clinical assessment,transthoracic echocardiography is also critical.It provides insight into the etiology of the mitral regurgitation,assesses for the presence of concomitant mitral stenosis or other valvular abnormalities,characterizes the severity of mitral regurgitation through an integrative approach and identifi es high risk findings including progressive left ventricular(LV)dilation and LV dysfunction.Surgical intervention is recommended for symptomatic patients and in asymptomatic patients with evidence of progressive LV dilation and a LV ejection fraction of less than 60%.While the presence of pulmonary hypertension and atrial fi brillation have been shown to be risk factors in degenerative mitral regurgitation,the same has not been demonstrated in rheumatic mitral valve disease.While mitral regurgitation may be reasonably well tolerated during pregnancy,symptomatic patients are at higher risk for adverse maternal and fetal outcomes,and therefore,it is recommended that mitral valve surgery be performed prior to pregnancy.Once the decision has been made to proceed to surgery,mitral repair,performed at a Heart Valve Center of Excellence is recommended if possible due to improved outcomes.Mitral valve repair is possible in>80%cases of rheumatic mitral regurgitation.If repair is not possible,replacement with either a bioprosthetic or mechanical valve are reasonable options.There are advantages and disadvantages to each approach and the choice of prosthesis should be a shared decision between the patient and her treatment team.
