The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound sign...The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound signals were denoised by using wavelet filters,the signals were applied bicoherence analysis that is an high order spectral analysis method.It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.展开更多
目的探究行体外循环下主动脉瓣置换术(aortic valve replacement,AVR)患者围术期心率变异性(heart rate variability,HRV)的变化趋势,以及年龄和(或)术后心房颤动(perioperativeatrial fibrillation,POAF)对这种趋势的影响程度。方法回...目的探究行体外循环下主动脉瓣置换术(aortic valve replacement,AVR)患者围术期心率变异性(heart rate variability,HRV)的变化趋势,以及年龄和(或)术后心房颤动(perioperativeatrial fibrillation,POAF)对这种趋势的影响程度。方法回顾性研究2021年1月至2023年1月在解放军北部战区总医院心血管外科行AVR的134例中、重度主动脉瓣疾病患者住院期间的基线资料,根据患者年龄和(或)是否并发POAF将患者分为A组(年龄<60岁、无POAF,49例)、B组(年龄<60岁并发POAF,21例)、C组(年龄≥60岁、无POAF,30例)、D组(年龄≥60岁并发POAF,34例),收集患者术前7 d与术后7 d动态心电图指标。观察患者围术期HRV变化。结果AVR术后7 d窦性心搏RR间期的标准差、24 h记录的所有5 min段中NN间隔的标准偏差的平均值(average of the standard deviations of NN intervals across all 5-minute segments recorded over a 24-hour period,SDNN_(idx))、R波时间间隔的方均根、连续RR间隔相差大于50 ms的百分比明显低于术前7 d,差异有统计学意义[(61.172±17.449)ms vs(804.567±230.518)ms、(20.284±9.432)ms vs(42.933±12.876)ms、(1.307±0.196)ms vs(1.412±0.148)ms,3.00(1.30,7.23)ms vs 5.30(3.00,10.40)ms,P<0.01];D组术后7 d SDNN_(idx)明显低于A组,差异有统计学意义[(42.568±14.749)ms vs(46.467±11.754)ms,P<0.05]。结论AVR术后早期自主神经功能紊乱,年龄≥60岁并伴POAF患者HRV指标显著下降,迷走神经功能受损加剧,两者协同作用加重紊乱。展开更多
孕妇30岁,孕2产0。本次单胎妊娠,22周行孕中期超声畸形筛查提示为胎儿主动脉瓣闭锁,主动脉狭窄伴反流,二尖瓣闭锁,左心室明显增大,考虑左心发育不良综合征(hypoplastic left heart syndrome,HLHS)。引产后胎儿基因检测结果为NOTCH1基因...孕妇30岁,孕2产0。本次单胎妊娠,22周行孕中期超声畸形筛查提示为胎儿主动脉瓣闭锁,主动脉狭窄伴反流,二尖瓣闭锁,左心室明显增大,考虑左心发育不良综合征(hypoplastic left heart syndrome,HLHS)。引产后胎儿基因检测结果为NOTCH1基因杂合变异,可致主动脉瓣病1型。胎儿尸解结果为主动脉瓣闭锁,二尖瓣增宽增厚,左心室增大伴心肌梗死。本文重点介绍该例HLHS伴左心室增大的超声表现及其血流动力学变化,以提高临床医师对HLHS疾病表型进行性改变的认识。展开更多
Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,poste...Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.展开更多
文摘The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound signals were denoised by using wavelet filters,the signals were applied bicoherence analysis that is an high order spectral analysis method.It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.
文摘目的探究行体外循环下主动脉瓣置换术(aortic valve replacement,AVR)患者围术期心率变异性(heart rate variability,HRV)的变化趋势,以及年龄和(或)术后心房颤动(perioperativeatrial fibrillation,POAF)对这种趋势的影响程度。方法回顾性研究2021年1月至2023年1月在解放军北部战区总医院心血管外科行AVR的134例中、重度主动脉瓣疾病患者住院期间的基线资料,根据患者年龄和(或)是否并发POAF将患者分为A组(年龄<60岁、无POAF,49例)、B组(年龄<60岁并发POAF,21例)、C组(年龄≥60岁、无POAF,30例)、D组(年龄≥60岁并发POAF,34例),收集患者术前7 d与术后7 d动态心电图指标。观察患者围术期HRV变化。结果AVR术后7 d窦性心搏RR间期的标准差、24 h记录的所有5 min段中NN间隔的标准偏差的平均值(average of the standard deviations of NN intervals across all 5-minute segments recorded over a 24-hour period,SDNN_(idx))、R波时间间隔的方均根、连续RR间隔相差大于50 ms的百分比明显低于术前7 d,差异有统计学意义[(61.172±17.449)ms vs(804.567±230.518)ms、(20.284±9.432)ms vs(42.933±12.876)ms、(1.307±0.196)ms vs(1.412±0.148)ms,3.00(1.30,7.23)ms vs 5.30(3.00,10.40)ms,P<0.01];D组术后7 d SDNN_(idx)明显低于A组,差异有统计学意义[(42.568±14.749)ms vs(46.467±11.754)ms,P<0.05]。结论AVR术后早期自主神经功能紊乱,年龄≥60岁并伴POAF患者HRV指标显著下降,迷走神经功能受损加剧,两者协同作用加重紊乱。
文摘孕妇30岁,孕2产0。本次单胎妊娠,22周行孕中期超声畸形筛查提示为胎儿主动脉瓣闭锁,主动脉狭窄伴反流,二尖瓣闭锁,左心室明显增大,考虑左心发育不良综合征(hypoplastic left heart syndrome,HLHS)。引产后胎儿基因检测结果为NOTCH1基因杂合变异,可致主动脉瓣病1型。胎儿尸解结果为主动脉瓣闭锁,二尖瓣增宽增厚,左心室增大伴心肌梗死。本文重点介绍该例HLHS伴左心室增大的超声表现及其血流动力学变化,以提高临床医师对HLHS疾病表型进行性改变的认识。
基金funded by National Nature Foundation of China ( 11532004,1140204,11832008)
文摘Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.
