多普勒超声心动图引导二尖瓣狭窄球囊扩张的研究

目的探讨经胸多普勒超声心动图在引导二尖瓣狭窄球囊扩张术中的作用.方法以彩色、连续波及脉冲波多普勒技术引导球囊扩张术中逐渐递增球囊直径,结合二维超声心动图及X线,共同对35例二尖瓣狭窄患者施行经皮穿刺二尖瓣球囊扩张术.结果所有患者均取得满意扩张效果,无一例出现重度二尖瓣反流.二尖瓣跨瓣流速由(2.47±0.46)m/s降至(1.68±0.37)m/s(P＜0.001),跨瓣压差由(25.10±9.60)mm Hg降至(12.27±4.72)mm Hg(P＜0.001),瓣口面积从(1.28±0.23)cm2扩大至(2.23±0.31)cm2(P＜0.001).结论应用多普勒超声心动图引导二尖瓣狭窄的球囊扩张既可达到充分扩张狭窄二尖瓣的目的,又可最大限度地避免和减少二尖瓣关闭不全的发生,较单纯X线引导的方法更为优越.     

多平面经食管超声心动图诊断二尖瓣膜瘤

目的探讨多平面经食管超声心动图（MTEE）诊断二尖瓣膜瘤（MVA）的价值。 方法对6例MVA患者行MTEE检查，仔细观察MVA位置、大小，是否有穿孔或破裂入左房，评价二尖瓣反流程度及是否合并主动脉瓣病变。 结果6例MVA均累及二尖瓣前叶，MTEE测量MVA大小平均约为13mm×16mm，均破裂入左房，破口大小平均约为6～7mm；6例均有二尖瓣反流，为中度或重度；3例存在主动脉瓣赘生物，另外2例合并二叶式主动脉瓣畸形；主动脉瓣反流程度均为中度而且偏心冲击二尖瓣前叶。 结论MTEE是一种能够客观、准确评价MVA较好的检查手段。     

多平面食管超声心动图在非风湿性心脏瓣膜病的应用研究

目的：应用多平面食管超声心动图(MTEE)观察32例非风湿性心脏瓣膜病, 进一步评价其临床作用及其特点。方法：采用MTEE5MHz探头在0～180°连续扫描。结果：MTEE诊断二尖瓣(MV)病变12例包括MV脱垂、腱索断裂、退行性变。MTEE连续在0～180°扫描, 显示MV纵断解剖结构及双交界区。主动脉瓣(AV)病变11例包括AV感染、先天性AV狭窄、AV穿孔。MTEE12°～70°AV短轴和80°～120°AV长轴获连续扫描图像, 清晰显示AV结构特点。三尖瓣(TV)病变6例, 包括三尖瓣下移畸形、TV脱垂、TV重度关闭不全(肺动脉高压).MTEE在四腔心水平由0～90°连续扫描获TV隔叶、前叶、后叶纵断切面及交界区AV水平0～140°由右室流入道扫查至流出道显示TV隔叶、后叶结构。肺动脉瓣(PV)病变3例。于门齿距25cm处30°～90°显示右室流出道PV长轴和0°～28°PV短轴。在AV和PV短轴面均能显示瓣叶数目、位置、形态结构, 而长轴面显示瓣叶开放状态, 尤其狭窄患者可显示瓣叶开放“圆顶征”.MTEE确诊32例中17例做了手术或心导管和心血管造影, 均获证实。MTEE诊断正确率较TTE提高34%.     

多普勒组织成像技术评价不同阶段左室舒张功能障碍的价值

目的探讨二尖瓣环前壁、下壁组织多普勒运动速度频谱在评价不同阶段左室舒张功能障碍中的意义。方法采用组织多普勒技术(Dopplertissueimaging,DTI)测定100例不同阶段左室舒张功能障碍患者及30例正常人的二尖瓣环前壁(mitralannu-lar/anteriorwall,MVA/AW)、下壁(mitralannular/inferiorwall,MVA/IW)运动速度频谱,并与其二尖瓣血流频谱(pulsivewave,PW)相比较。结果①弛张功能减阶段,PW-E/A,MVA/AW-E/A及MVA/IW-E/A均降低(P<0.01),MVA/AW-E/A与PW-E/A高于MVA/IW(100%和60%,P<0.01)。②假性正常化阶段,PW-E/A与正常比较,差异无显著意义(P>0.05),MVA/AW-E/A、MVA/IW-E/A降低,差异有显著性意义(P<0.01),且MVA/AW-E/A与PW-E/A符合率底于后者(20%和40%,P<0.01)。③限制性充盈阶段,3组E/A均高于正常差异有显著性意义(P<0.01),但MVA/IW-E/A与PW-E/A符合率明显高于MVA/AW-E/A(89%和22%)。结论多普勒组织成像技术测定二尖瓣环前壁、下壁运动频谱在评价左室舒张功能减退中具有重要价值。且在评价不同阶段左室舒张功能障碍时,二尖瓣环前壁及下壁分别具有不同意义。     

超声负荷试验对26例经皮球囊二尖瓣成形术前后综合心功能评价

目的研究静息及不同运动状态下心脏血流动力学及二尖瓣口面积变化,更客观、全面地评价PBMV术疗效.方法静脉滴注异丙肾上腺素提高心率,模拟轻、中、重度体力活动,分别于术前、术后采用超声心动图观察MVA、MVG、Vmax、CO、EF等项指标.结果二尖瓣狭窄患者26例,男性9例,女性17例,年龄34.3±6.8岁.PBMV术前行超声负荷试验时随着心率逐步增快(在基础心率上提高20～60次/min)MVG(14.23±6.44mmHg增至21.84±8.06mmHg P＜0.05)、Vmax (1.65±0.38 m/s增至2.81±0.36 m/sP＜0.05)明显升高;MVA(0.89±0.31 cm2至0.92±0.20 cm2 P＞0.05)、CO(3.98±1.36 L/min至4.70±1.11 L/min P＞0.05)、EF(56.8±6.4%至64.8±8.4%P＞0.05)无显著改变,提示二尖瓣储备、心功能储备几近丧失.PBMV术后静息状态下MVA由0.89±0.31 cm2增至2.03±0.36 cm2,MVG由14.23±6.44mmHg下降至3.63±1.64mmHg(P＜0.05),运动负荷状态下MVA由2.03±0.36cm2增至2.48±0.40 cm2,CO由5.27±0.86 L/min增至10.20±0.93L/min(P＜0.05),提示二尖瓣储备、心功能储备部分恢复.结论PBMV术导致MVA增大同时其储备功能部分恢复.二尖瓣储备较术后静息状态下MVA值对心功能的评价具有更大价值.     

经皮二尖瓣球囊成形术治疗二尖瓣狭窄伴轻中度二尖瓣关闭不全的疗效评价

目的:探讨风湿性心脏病(RHD)二尖瓣狭窄(MS)伴轻中度二尖瓣关闭不全患者经皮二尖瓣球囊成形术(PBMV)的效果。方法:将33例二尖瓣狭窄伴轻度关闭不全(A组)和30例二尖瓣狭窄伴中度关闭不全(B组)及36例单纯二尖瓣狭窄(C组)的PBMV术后即刻及随访结果作对比研究。结果:A组左房平均压(MLAP)从术前(25.2±5.6)mmHg降至术后(10.2±3.2)mm-Hg,B组左房平均压(MLAP)从术前(26.3±5.2)mmHg降至术后(10.9±4.2)mmHg,C组左房平均压(MLAP)从术前(23.8±7.1)mmHg降至术后(9.5±4.2)mmHg,三组间比较P>0.01,差别无显著性。A组二尖瓣返流术前(14±3.5)％,术后(15±2.6)％,P>0.01,差别无显著性;B组二尖瓣返流术前(30±6.8)％,术后(35±4.5)％,P>0.01,差别无显著性;C组术前0％,术后(2±0.2)％,P>0.01,差别无显著性。A组、B组、C组随访左房内径逐渐缩小。结论:MS合并轻中度二尖瓣返流,PBMV是一种有效和安全的治疗措施,可列入PBMV的手术适应症。     

Duran环在二尖瓣成形术中的应用

目的:总结使用Duran环进行二尖瓣成形术的经验.方法:回顾性分析我院自2007年10月至2011年3月采用Duran软环治疗二尖瓣关闭不全95例,其中87例成功进行二尖瓣成形,男48例,女39例,年龄18 ～ 73(平均42.7)岁.手术方法为常规体外循环下使用二尖瓣前后叶折叠缝合或矩形切除等技术修复二尖瓣病变,同时所有病例均应用Duran软环.结果:8例因成形后监测仍有中量以上返流,改性二尖瓣置换术,其余患者术中食管超声无反流49例,微量反流24例,轻度反流14例,均行二尖瓣成形术.平均体外循环时间(112.4±52.1) min,主动脉阻断时间(81.1±46.2) min.二尖瓣成形的患者出院前超声心动图检查测量左房直径、左室舒张末直径与术前相比均显著缩小,心功能均明显恢复,其中心功能Ⅰ级66例(75.9％),Ⅱ级21例(24.1％).结论:二尖瓣成形术中使用Duran环可更好地维持左室的生理功能,结合其他成形技术使用,可取得良好效果,但需注意避免环缩过度引起的二尖瓣狭窄.     

超声心动图评价二尖瓣前叶脱垂缘对缘成形术效果

目的 应用经胸超声心动图(TTE)评价二尖瓣前叶脱垂缘对缘成形术效果.方法 随机对19例二尖瓣前叶脱垂患者行缘对缘成形术患者术前及术后进行TTE检查,检测二尖瓣反流(MR)程度、二尖瓣口面积(MVA),左房、左室大小,左室射血分数(LVEF)及肺动脉收缩压(PASP).结果 二尖瓣前叶脱垂缘对缘成形术前瓣膜重度反流19例,术后无反流1例,轻微反流15例,轻度反流3例;术前左房大小为(51.63±10.03)mm,术后为(44.79±9.22)mm(P=0.000);术前左室大小为(59.37±8.29)mm,术后为(52.68±7.31)mm(P=0.000);术前PASP为(45.37±18.34)mm Hg(1 mm Hg=0.133 kPa),术后为(33.00±9.43)mm Hg(P=0.002);术前MVA为(4.13±0.24)cm<'2>,术后为(2.90±0.28)cm<'2>(P=0.000);术前LVEF为(66.0±9.0)%,术后为(67.0±6.0)%(P=0.751).结论 缘对缘成形术是一种简单、有效保留瓣下结构,恢复左房、室正常形态,维护左室功能的手术方法 .     

左房黏液瘤临床特征及经胸超声心动图对其的诊断价值

目的探讨左房黏液瘤的临床特征及经胸超声心动图对其的诊断价值。方法 65例经手术病理确诊的左房黏液瘤患者,应用经胸超声心动图测量瘤体最大径、左房内径、二尖瓣反流、三尖瓣反流、肺动脉收缩压(PASP)、左室射血分数(LVEF)及二尖瓣口面积(MVA)。根据MVA测值将患者分为>2 cm2组44例(A组)和≤2 cm2组21例(B组),比较两组患者一般临床特征和超声心动图指标差异,分析瘤体最大径与PASP及MVA间的相关性。结果两组患者性别、年龄、胸部不适症状比例及LVEF比较差异均无统计学意义,两组患者栓塞症状比例、瘤体最大径、左房内径、二尖瓣反流、三尖瓣反流及PASP比较差异均有统计学意义(P<0.05)。58例患者瘤体最大径与PASP呈正相关(r=0.62,P<0.01);A组患者瘤体最大径与MVA呈负相关(r=-0.70,P<0.01)。结论左房黏液瘤瘤体最大径与PASP及MVA相关;经胸超声心动图对左房黏液瘤的诊断有重要价值。     

先天性心脏病患儿合并二尖瓣反流的外科处理策略

目的探讨在婴幼儿先天性心脏病合并二尖瓣反流时,积极或者保守的二尖瓣处理策略间的区别。方法回顾性分析2008年6月至2011年1月127例先天性心脏病合并二尖瓣反流患儿的临床资料,手术年龄为68～5261(627.58±986.32)d,体重3.8～54(8.90±6.83)kg,男57例,女70例。第一诊断包括室间隔缺损(89例)、动脉导管未闭(13例)、房间隔缺损(9例)、主动脉缩窄(7例)、冠状动脉起源异常(4例)、主动脉瓣狭窄(3例)、冠状动脉右心室瘘(1例)、主动脉弓中断(1例)。以是否进行二尖瓣整形为标准,将患者分为两组,其中67例进行了包括第一诊断和二尖瓣整形在内等的矫治手术,而另外60例则未对二尖瓣进行处理。除了主要诊断的外科矫治外,二尖瓣整形手术包括二尖瓣环缩、裂缺缝合、二尖瓣双孔等。随访时间7～1131(235.39±247.81)d。术前、术后随访主要参考依据为经胸多普勒超声,少部分患者术后采用经食道多普勒超声进行评估。结果二尖瓣整形组术前二尖瓣反流轻度12例(17.91%),轻中度反流24例(32.84%),中度反流29例(43.28%),中重度反流1例(1.49%),重度反流1例(1.49%);未整形组则相应为:轻度反流6例(10%)、轻中度反流39例(65%)、中度反流14例(23.33%)、重度反流1例(1.67%)。随访过程中无死亡病例,结果显示,二尖瓣整形组患者二尖瓣反流加重3例,维持原状15例,减轻49例;二尖瓣未处理组,二尖瓣反流加重3例,维持原状14例,减轻44例。对两组患者术前术后的二尖瓣反流状况的改变进行非参数Wilcoxon秩和检验,无统计学差异(P<0.05)。对中度以上二尖瓣反流患者的对比发现,积极外科处理与保守治疗之间无统计学差异(P<0.05);单纯对室间隔缺损合并二尖瓣反流患者的分析两组之间也无统计学差异(P<0.05),13例动脉导管未闭患者均未对二尖瓣进行处理,术后二尖瓣反流均有改善(100%)。结论在儿童患者中,二尖瓣反流     

New quantitative three-dimensional echocardiographic indices of mitral valve stenosis

Background We studied the value of quantitative three-dimensional echocardiography (3DE) in the evaluation of mitral valve stenosis using the measurement of the mitral valve area (MVA) with two new indices: the doming volume and mitral valve volume. Methods and results A total of 45 consecutive patients with mitral valve stenosis were studied. MVA was measured using Doppler with the pressure half-time (PHT) method. Following a diagnostic multiplane transesophageal (TEE) examination, data for 3DE were acquired with a rotational mode of acquisition. MVA was assessed by anyplane echocardiography (APE) and from surface rendered images. Moreover, the doming volume, i.e., the volume subtended by the anterior and posterior mitral valve and annular cut plane was measured by APE. Comparing PHT-derived with 3DE-derived MVA’s, using both APE and surface rendered images, only moderate correlations were observed: PHT-derived MVA versus APE-derived MVA: r = 0.74, P < 0.0001; PHT-derived area versus 3DE-surface rendered MVA: r = 0.70, P < 0.0001. Multiple linear regression analysis showed a relation of atrial fibrillation to the doming volume (P = 0.04), but not to PHT-derived MVA (P = 0.28), APE-derived area (P = 0.33) and mitral valve volume (P = 0.08). Comparison of patients with MVA < 1 cm² and MVA > 1 cm² revealed significant difference in mitral valve volume: mean mitral valve volume in critical stenosis was 3.7 ml versus 1.4 ml in non-critical stenosis (P = 0.04). Conclusions Only moderate correlations between 3DE and Doppler-derived MVA’s were observed. Measurement of the doming volume allows quantification of the 3DE geometry of the mitral apparatus. Patients with conical or funnel-like geometry are more likely to have sinus rhythm, whereas, patients with flat geometry are likely to have atrial fibrillation. Mitral valve volume can be used for the evaluation of mitral stenosis severity. These new 3DE indices might be used for selection of patients for balloon valvuloplasty.     

Color flow imaging of the vena contracta in mitral regurgitation: technical considerations.

Qualitative grading of mitral regurgitation severity has significant pitfalls secondary to hemodynamic variables, sonographic technique, blood pool entrainment, and the Coanda effect. Volumetric and proximal isovelocity surface area methods can be used to quantitate regurgitant orifice area, regurgitant volume, and regurgitant fraction, but have several limitations and can pose technical challenges. The vena contracta width method provides a rapid and accurate quantitative assessment of mitral regurgitation severity, but is clinically underused. This article is intended to generate an understanding of the flow mechanics of the vena contracta and the sonographic technique required to provide consistent and accurate measurements of vena contracta width in patients with mitral regurgitation.     

Doppler color flow imaging: a new technique for visualization and characterization of the blood flow jet in mitral stenosis

We used Doppler color flow imaging, a new noninvasive technique for mapping of intracardiac blood flow, to visualize and characterize the blood flow jet in 42 patients with mitral stenosis. Color flow imaging provides information about the direction of blood flow, its velocity, and the presence of turbulence. Although we found various jet configurations, most frequently the jet was centrally and apically directed and had a "candle flame" appearance (a central blue zone surrounded by hues of yellow and orange). The blood flow jet can be used to guide the positioning of the continuous-wave Doppler beam parallel to the blood flow; thus, the accuracy of the Doppler data can be enhanced. This new technology has promising potential for other clinical applications in cardiology.     

Clinical and echocardiographic evaluation of mitral valve aneurysms: a retrospective,single center study

Mitral valve aneurysms (MVAs) are rarely encountered in echocardiography laboratories. Although they are commonly associated with endocarditis of the aortic valve, various mechanisms have been suggested for the etiopathogenesis of MVAs associated with non-infectious conditions. 5,887 patients who underwent transesophageal echocardiography (TEE) between 2007 and 2012 were evaluated retrospectively for MVA. Mitral valve aneurysm is defined as a localized saccular bulging of the mitral leaflet towards the left atrium with systolic expansion and diastolic collapse. The color flow Doppler image of a perforation was described as a high-velocity turbulent jet traversing a valve leaflet in systole. We found that 12 of 5,887 patients (0.204 %) had MVA in TEE examinations. The mean age of patients with MVA was 53 years (range 21–80 years), including four females and eight males. Nine patients presented with symptoms of endocarditis. On TEE, aneurysms were located in the anterior mitral leaflet in 11 patients, and in the posterior mitral leaflet in one patient. Eight patients had severe, three had moderate, and one had trace mitral regurgitation. Of the nine patients with perforated leaflets, eight patients had severe and one patient had moderate mitral regurgitation. Aortic regurgitation was present in nine patients, being severe in three, moderate in two, mild in two, and trace in two patients. Two patients without severe mitral regurgitation were followed-up conservatively, while nine patients underwent surgery. Two patients died from septic shock, one in the postoperative period and the other one prior to surgery. Although MVAs occur during the course of aortic valve endocarditis and, in particular, due to aortic regurgitation jet, it should be borne in mind that they may develop as an isolated valvular pathology and may be misdiagnosed as chordal rupture, other cardiac masses, or vegetation. Thus, MVAs may not be so infrequent as they are thought; they may justify to be considered in the differential diagnosis of masses seen on the mitral valve on echocardiographic examination.     

Mitral valve A wave and mitral stenosis

We examined M-mode echocardiograms on 35 patients with catheterization-proven mitral stenosis and normal sinus rhythm to determine whether the presence or absence of an A wave on the mitral echogram predicted mild versus severe mitral stenosis. Mitral valve area (MVA) was determined by the Gorlin formula. Presence of a mitral A wave was defined as 2 mm or greater anterior motion (after a well-defined F point) of the anterior mitral leaflet. In six of 35 patients, the presence of an A wave was equivocal. Of the remaining 29 patients, 16 had no A wave and mean MVA = 1.18 cm² ± 0.45 (SD), and 13 patients had a definite A wave and mean MVA = 2.04 cm² ± 0.71. There was a significant difference (p < 0.001) between the mean MVA for patients with and without definite A waves. No patients with a definite A wave had an MVA less than 1.2 cm². An A wave on the mitral echogram (in sinus rhythm) excludes severe mitral stenosis; when an A wave is not seen, no definite statement concerning severity of mitral stenosis can be made.     

Quantification of mitral valve regurgitation with color flow Doppler using baseline shift

Vena contracta width (VCW) and effective regurgitant orifice area (EROA) are well established methods for evaluating mitral regurgitation using transesophageal echocardiography (TEE). For color-flow Doppler (CF) measurements Nyquist limit of 50–60 cm/s is recommended. Aim of the study was to investigate the effectiveness of a baseline shift of the Nyquist limit for these measurements. After a comprehensive 2-dimensional (2D) TEE examination, the mitral regurgitation jet was acquired with a Nyquist limit of 50 cm/s (NL50) along with a baseline shift to 37.5 cm/s (NL37.5) using CF. Moreover a real time 3-dimensional (RT 3D) color complete volume dataset was stored with a Nyquist limit of 50 cm/s (NL50) and 37.5 cm/s (NL37.5). Vena contracta width (VCW) as well as Proximal Isovelocity Surface Area (PISA) derived EROA were measured based on 2D TEE and compared to RT 3D echo measurements for vena contracta area (VCA) using planimetry method. Correlation between VCA 3D NL50 and VCW NL50 was 0.29 (p < 0.05) compared to 0.6 (p < 0.05) using NL37.5. Correlation between VCA 3D NL50 and EROA 2D NL50 was 0.46 (p < 0.05) vs. 0.6 (p < 0.05) EROA 2D NL37.5. Correlation between VCA 3D NL37.5 and VCW NL50 was 0.45 (p < 0.05) compared to 0.65 (p < 0.05) using VCW NL37.5. Correlation between VCA 3D NL37.5 and EROA 2D NL50 was 0.41 (p < 0.05) vs. 0.53 (p < 0.05) using EROA 2D NL37.5. Baseline shift of the NL to 37.5 cm/s improves the correlation for VCW and EROA when compared to RT 3D NL50 planimetry of the vena contracta area. Baseline shift in RT 3D to a NL of 37.5 cm/s shows similar results like NL50.     

Transesophageal color flow Doppler mapping in the assessment of native mitral valvular regurgitation: comparison with left ventricular angiography.

Transesophageal echocardiography (TEE) was performed within 24 hours after cardiac catheterization in 45 patients for assessment of native mitral valvular regurgitation. Color flow mapping was used in evaluating systolic regurgitant jet sizes. A jet demonstrated by TEE was 96% sensitive and 44% specific for angiographic mitral regurgitation. The presence of angiographic mitral regurgitation was best predicted by (single measurement) (1) a holosystolic jet, (2) a jet length greater than 2.5 cm, and (3) a jet area greater than 2 cm2. Severe angiographic mitral regurgitation (grades 3 and 4) was best predicted by (single measurement) (1) a jet area greater than 5 cm2, and (2) a jet length greater than 4 cm. It is concluded that the assessment of angiographic mitral regurgitation by TEE is improved by the measurement of these jet parameters, which have a high sensitivity and higher specificity than the presence of a jet alone. Furthermore, with TEE one is able to differentiate severe (grades 3 and 4) from absent or mild mitral regurgitation (grades 0, 1, and 2).     

自动测量心搏出量改进法定量评价偏心性二尖瓣反流

目的研究并证实自动心脏输出量测量法(ACOM)改进法定量评价二尖瓣偏心性反流。方法对19例患偏心性反流患者采用ACOM改进法,于收缩相对经二尖瓣反流瓣口的血流速度直接进行时间和空间双重积分,得到二尖瓣反流量,并将反流量作为评价参数,对患者的反流严重程度进行划分。最后,比较分析反流量与由实时三维彩色多普勒超声心动图测量得到的射流容积和反流狭径宽度之间的相关性。结果以反流量大小作为标准,3例患者被判定为轻度,10例患者被判定为中度,6例患者被判定为重度。ACOM改进法得到的反流量与射流容积(r=0.9371)和反流狭径宽度(r=0.8939)高度相关。结论ACOM改进法是对偏心性二尖瓣反流进行定量的有效方法。     

实时三维超声心动图评价风湿性二尖瓣狭窄瓣口面积的初步探讨

目的　探讨实时三维超声心动图评价二尖瓣狭窄瓣口面积的可行性和准确性。方法　分别应用二维超声平面法、多普勒压差降半时间法和实时三维容积法检测 18例风湿性二尖瓣狭窄患者的二尖瓣瓣口面积 ,并和 3 4例正常人对照。结果　分别在二尖瓣狭窄组和对照组内 ,二维平面法、压差降半时间法与实时三维容积法测量的二尖瓣口面积均呈高度相关 (二尖瓣狭窄组 :r =0 .98,r =0 .89;正常组 :r =0 .94,r =0 .91) ;三维容积法测得的瓣口面积在正常组与二尖瓣狭窄组之间差异有显著性意义 (P <0 .0 0 0 1) ;经三维容积法测得的瓣口面积略小于二维法 (二尖瓣狭窄组 :1.3 1cm2 对 1.40cm2 ;正常组 :4.63cm2 对 4.76cm2 )。结论　实时三维超声心动图能实时显示二尖瓣口的整体形态 ,同时更容易快速切取到瓣口最小面积平面 ,可准确反映瓣膜狭窄的真实程度 ,为临床诊断和治疗提供一种新的定量分析方法。     

Quantifying Mitral Regurgitation: Added Value of Three-Dimensional Echocardiography

Current three-dimensional (3D) echocardiographic technology, including live 3D transesophageal echocardiography and single-beat 3D color Doppler imaging, are providing valuable new insight into the mechanism and quantification of mitral valve dysfunction. In this review we discuss important applications of 3D volumetric leaflet imaging with emphasis on the distinction between organic and functional mitral regurgitation. We also discuss the added benefit of current and emerging 3D color Doppler methods for the quantification of mitral regurgitation severity. The limitations of the 2D proximal isovelocity surface area method are discussed, along with potential solutions provided by 3D color Doppler imaging methods that do not require assumptions about the converging flow geometry. Methods to directly measure the vena contracta area of a regurgitant jet are presented along with recent validation studies comparing this method to a reference standard of cardiac MRI. In brief, we review the established and emerging applications of 3D color Doppler techniques for the quantification of mitral regurgitation severity.