螺旋心肌带理论应用于心脏扭转运动的基础与临床研究

发布时间：2018-03-29 20:43

本文选题：螺旋形心肌带　切入点：心脏扭转运动　出处：《中国人民解放军医学院》2015年博士论文

【摘要】：目的1.借助磁共振成像追踪正常人心脏的一个完整心动周期中左心室壁的运动过程,结合已知的螺旋心肌带解剖理论对心脏扭转和解旋的各个时期的心室运动进行分析,尝试揭示心肌带各节段与心室运动之间的联系。2.采用磁共振技术研究正常人心尖环与基底环在心脏扭转运动中各自相反方向的旋转角度、速率及同步性,进一步分析其发生机制,并与不同部位心梗患者心脏扭转运动的差异进行比较。3.通过对心梗患者接受冠状动脉旁路移植术前后的心脏扭转运动变化进行自身比较,尝试评价心脏扭转角度能否作为心功能评价的敏感指标,并进一步讨论其临床应用价值。材料与方法1.将不同种属的心脏(猪心、羊心)按照不同时间煮熟后,按照以往心肌带的研究中所描述的解剖方法进行解剖,将解剖好的心脏自然伸展,对各个节段进行染色标记并恢复至心脏原形,按照磁共振扫描层面对复原后的心脏进行切开,对横断面心肌带结构进行观察并分析磁共振同一短轴切面与心肌带对应关系。2.采用瞬时速度向量对20例正常人进行磁共振扫描后分析其四腔心切面心肌的运动规律。使用TOMTEC Imaging System软件在心脏舒张末期对心内膜进行准确描记,将左室内膜分为48个节段并对每个节段点在完整心动周期内每一帧的运动方向进行追踪,根据速度矢量的方向及大小分析等容收缩期、扭转运动、等容舒张期及快速舒张期的各个时期室壁各部分的运动顺序性。3.对54例不同年龄、不同性别的正常人心脏进行扫描并获得从心底至心尖的心室二腔切面,根据之前离体心脏磁共振扫描的解剖定位获取每位志愿者心底和心尖扫描的同一层面进行分析,同样对心内膜进行准确描记并追踪每个点在心动周期中的切向运动的最大旋转角度、峰值速率及达峰时间。以逆时针方向作为正向,将心尖与心底的旋转角度差值作为扭曲角度,分析正常人心脏扭转运动的规律。4.纳入心梗患者33例,其中下壁心梗17例,前壁心梗16例,分别分析两组患者的心尖环及心底环的最大旋转角度、峰值旋转及解旋速率和达峰时间,将结果与正常人心脏扭转结果进行比较并分析其差异性。5.对12例既往有心梗病史并接受冠状动脉旁路移植术的患者的术前、术后MRI进行自身比较,分析心尖环、心底环各个扭转指标的变化情况,讨论心脏扭转指标对心功能评价的意义。结果1.采用相对统一的解剖方式,所有心脏均可解剖为一个完整的心肌带,分为基底环和心尖环两个环,其中基底环又分为左室段和右室段,心尖环分为降段和升段;室间隔由降段和升段构成,没有基底环包绕,而左室游离壁的上三分之二有基底环覆盖因而有三层心肌;心内膜及室间隔左室面由心肌带降段构成而心外膜及室间隔右室面由升段构成,且升段和降段在室间隔的上部与下部构成比例不同。2.通过对心肌的速度向量追踪发现,心脏在收缩前期主要为缩窄及逆时针旋转运动,该时期主要以基底段及降段收缩为主,速度向量观察发现室间隔开始运动而侧壁尚未运动；在射血期心尖呈逆时针而心底呈顺时针运动,心脏呈“拧毛巾”样扭转运动,可以观察到室间隔上部和下部呈扭转运动,并且周围室壁向心尖靠拢,心室腔明显缩短;在等容舒张期基底环和降段停止收缩,而升段仍继续收缩,该间期约80-90ms,此时心脏主动抽吸解旋,同时伴随着心脏整体顺时针旋转;在舒张期心脏先拉长,继而变宽,心脏由主动解旋变为被动充盈。整个心脏运动分为缩窄、扭转、拉伸、变宽四个阶段,每个阶段的运动是心肌带各节段共同运动的结果所致。3.正常心脏扭转运动中,心尖呈逆时针运动,最大旋转角度约10.2+4.8°,峰值旋转及解旋速度分别为51.1±30.5°/s和-38.6+28.1°/s,达峰时间为234.1+42.3ms;心底呈顺时针方向运动,最大旋转角度约7.0+3.3°,峰值旋转及解旋速度-43.1+22.8°/s和29.4+26.9°/s,达峰时间为312.1+56.20ms。心尖旋转角度明显大于心底,并且心尖解旋早于心底,该时间间隙约78.0±14.0ms,此间隙期间心脏主动舒张解旋运动。4.前壁心梗患者心尖及基底的最大旋转角度明显下降(P0.05),并且其旋转速度和解旋速率都低于正常组,但差异无统计学意义；前壁心梗组心尖解旋时间明显延迟,心脏主动解旋间隙消失,表示心脏收缩及舒张功能均受损。下壁心梗患者的心底最大旋转角度及旋转速度均明显下降(P0.05),而心尖旋转角度及速度与正常组无明显差异;其主动解旋时间间隙仍存在但较正常组明显缩短。5.患者接受冠状动脉旁路移植术后3个月至1年时,心尖及基底旋转运动明显改善,旋转及解旋速率明显提高,心脏收缩功能增强,心脏扭转指标与EF改善相关性良好,相关系数r=0.83,p0.05。结论1.心肌带结构及心脏扭转运动在哺乳动物中可能具有普遍性和一致性,本研究首次结合扭转运动评价的金标准——磁共振技术对心动周期室壁各个部分在不同时刻的运动进行分析,并发现心肌带解剖结构与左室顺序性运动密切相关；2.借助最新的心脏磁共振追踪技术,我们进一步总结了正常人心脏扭转运动的规律,并发现心尖呈逆时针运动,心底呈顺时针运动,心脏呈“拧湿毛巾”运动;并揭示了心尖的解旋时间早于心底,该时间差值约70-80ms,此期间心脏主动舒张解旋抽吸,这一发现对心脏舒张功能的研究具有重要意义；3.首次将心梗后病理改变下心脏扭转运动与正常人心脏扭转运动进行比较,发现心尖及心底旋转运动明显下降,旋转速率及解旋速率明显降低,且解旋时间延迟,心脏主动解旋抽吸时间明显缩短甚至消失,心脏舒张功能受损；4.首次采用磁共振评价冠状动脉旁路移植术对心脏扭转运动的影响,并发现心梗患者接受冠状动脉旁路移植术后心脏扭转运动明显提高,包括心尖和心底的旋转运动,初步证明心脏扭转运动指标对心功能改善情况的评估具有一定的敏感性,今后对其他病理改变下心脏扭转运动的评价有可能具有潜在的临床应用价值。
[Abstract]:1. by means of magnetic resonance imaging tracking of a complete cardiac cycle in normal cardiac left ventricular wall motion, myocardial anatomy with known binding helix theory in different periods of cardiac torsion and untwisting of ventricular motion analysis, try to reveal the myocardial band segments and ventricular motion contact.2. by magnetic resonance imaging normal people and technology tip ring ring in basal rotation angle in each cardiac twist in the opposite direction, speed and synchronization, further analysis of the mechanism, and different parts of myocardial infarction cardiac twist difference were compared by.3. on myocardial infarction in patients undergoing cardiac torsion before and after coronary artery bypass grafting of the movement itself comparison, try a sensitive index for evaluating cardiac torsion angle can be used as the evaluation of cardiac function, and discuss its clinical value and material. 1. different species (pig, sheep heart heart) according to different time after cooked, were dissected according to the anatomical method described in previous studies of myocardial band, the anatomy of good heart naturally stretch, were labeled and restored to the original shape of the heart of each segment, according to MRI in recovery the heart is open, to observe and analyze the magnetic resonance with a short axis and with the relation of.2. by analysis of myocardial motion fourth chamberview myocardial instantaneous velocity vector magnetic resonance imaging was performed in 20 cases of normal people on the cross section structure. Using TOMTEC Imaging myocardial band of System software in the end of diastole of endocardium of accurate recording of left ventricular endocardium, will be divided into 48 segments and each segment of track in the whole cardiac motion direction of each frame period, according to the analysis of the velocity vector direction and magnitude Isovolumic contraction, torsion, motion sequence of each part of the.3. of each period ventricular isovolumic relaxation and diastolic in 54 cases of normal people of different age, different sex heart scan and get from the bottom to the apex of the heart two chamber view, according to the analysis before the anatomical location of cardiac magnetic resonance scanning body for each volunteer heart and apical scanning the same level, the same on endocardial tracings and accurate tracking of each point in the cardiac cycle of the tangential movement of the maximum rotation angle, the peak rate and peak time. In the counterclockwise direction as positive, the rotation angle of the base and apex difference as the twist angle analysis, normal cardiac twist movement.4. included 33 cases of myocardial infarction patients, including 17 cases of myocardial infarction, 16 cases of anterior wall infarction, respectively analysis of the large rotation of apical ring and two groups of patients with heart ring Angle of rotation and peak untwisting rate and peak time, the results with normal cardiac twist results were compared and analyzed the difference of.5. in 12 patients with myocardial infarction and underwent coronary artery bypass grafting in patients with MRI compared with preoperative, postoperative, analysis of apical ring, the change of heart each ring torsion index, discuss the evaluation index on heart function and cardiac twist significance. Results 1. of the anatomical relatively uniform, all the heart can anatomy as a complete myocardial band divided into basal and apical ring, ring two ring, wherein the base ring is divided into the left ventricular and right ventricular apical segment. The ring into the descending and ascending segment; ventricular septal by descending and ascending sections, no basal ring wrapped, and 2/3 of the left ventricular free wall basal ring cover and a three layer of myocardium; left ventricular endocardial and ventricular septal surface by myocardial segments with reduced heart The adventitia and septal right ventricular surface by ascending segments and the ascending segment and descending the proportion of different.2. in the upper and lower chamber through the interval velocity vector on myocardial tracked cardiac contraction in the first major for coarctation and counterclockwise rotation, the period mainly in the basal and descending contraction. The velocity vector observation of ventricular septal and lateral wall movement has not yet started moving; in the ejection period of apical clockwise clockwise movement and the heart, the heart is like "wring a towel" twist, can be observed in the upper and lower septal twisting motion, and the surrounding wall close to the apex, left ventricular cavity was significantly shortened in isovolumic relaxation; basal ring and descending and ascending part of the end of the contraction continued to shrink, the interval of about 80-90ms, at the heart of active suction untwist, accompanied by the whole heart diastolic clockwise rotation; in the first pull long, then change Heart wide, by the active unwinding into passive filling. The heart movement is divided into narrow, twisting, stretching, width of four stages, each stage is the movement of each segment with myocardial common motion results caused by.3. normal cardiac twist, apical clockwise motion, maximum rotation angle of about 10.2+4.8 DEG, peak rotation and untwisting velocity were 51.1 + 30.5 ~ /s and -38.6+28.1 ~ /s, the peak time is 234.1+42.3ms; the heart in a clockwise direction, the maximum rotation angle of about 7.0+3.3 DEG rotation and peak untwisting velocity -43.1+22.8 ~ /s and 29.4+26.9 ~ /s, the peak time of 312.1+56.20ms. apical rotation angle is greater than that in the bottom of my heart and, the apical untwisting early in the heart, the time gap of about 78 + 14.0ms, the gap during the maximum rotation angle of heart diastolic untwisting active.4. anterior myocardial infarction in patients with apical and basal decreased significantly (P0.05), and the rotating speed And the unwinding rate are lower than the normal group, but the difference was not statistically significant; anterior myocardial infarction apical unwinding time was delayed and the active heart untwisting gap disappeared, cardiac systolic and diastolic function that were impaired. The heart maximum rotation angle in patients with myocardial infarction and the rotation speed were significantly decreased (P0.05), while the apex the rotation angle and speed and no significant difference between the normal group; the active unwinding time gap still exists but compared with the normal group was significantly shorter in patients with.5. for 3 months to 1 years after coronary artery bypass grafting, apical and basal rotation significantly improved, rotation and untwisting rate increased significantly, cardiac systolic function enhancement cardiac twist index and EF improve the good correlation, correlation coefficient r=0.83, p0.05. conclusion 1. myocardial band structure and cardiac twist may have universality and consistency in mammals, this study first combined torsional transport The gold standard to assess the dynamic magnetic resonance imaging to cardiac cycle were analyzed in different parts of the ventricular wall movement of the moment, and found that the anatomical structure of left ventricular myocardial band and sequential movements are closely related; 2. with cardiac magnetic resonance tracking the latest technology, we further summarized the normal cardiac twist movement rules, and found the apical clockwise movement, the heart in a clockwise motion, the heart was wrung wet towel "movement; and reveals the apical unwinding time early in the bottom of my heart, the time difference is about 70-80ms, the active diastolic untwisting during heart pumping, this finding has important significance to the study of cardiac diastolic function; 3. for the first time the pathological changes after myocardial infarction cardiac torsion and normal cardiac twist were compared, found that heart apex and rotational motion decreased, rotation rate and untwisting rate decreased obviously, and the solution spinning The delay between the active unwinding, heart pumping time shortened obviously and even disappeared, cardiac diastolic dysfunction; 4. for the first time using magnetic resonance assessment of coronary artery bypass grafting on cardiac twisting motion, and found that the myocardial infarction patients undergoing coronary artery bypass grafting after cardiac twist is improved obviously, rotary motion including apical and heart, preliminary proof heart motion reverse the assessment indicators to improve the situation of cardiac function has certain sensitivity, the other pathological changes of heart torsion evaluation may have potential clinical value.

【学位授予单位】：中国人民解放军医学院
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R654.2

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