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.     

经皮二尖瓣球囊成形术在二尖瓣狭窄伴重度心力衰竭时的应用

介绍二尖瓣狭窄伴重度心力衰竭（心衰）患者实施经皮二尖瓣球囊成形术（PBMV）的结果和初步体会。9例患者中男6例，女3例，年龄24～52岁，全部患者心功能均为Ⅳ级（按NYHA分级），术前抗心衰药物治疗效果极不理想。经施行PBMV后，血流动力学明显得已改善：左房平均压由术前4．34±1．02kPa（1kPa=7．5mmHg）降至术后1．64±0．82kPa，二尖瓣跨瓣压差由术前3．26±0．84kPa降至术后0．72±0．56kPa；瓣口面积由术前0．78±0．30cm~2增至术后2．11±0．24cm~2，左房内径术后较术前缩小了约10mm（P值均＜0．001）；在短期内心功能迅速恢复至Ⅰ～Ⅱ级，运动耐量明显增加，心衰症状缓解率达100％。作者认为：二尖瓣狭窄伴重度心衰时，只要排除了加重心衰的其他原因，应尽早施行PBMV，PBMV是一种安全、可靠和行之有效的治疗方法。作者同时对PBMV时球囊方式选择及并发症的防治进行了讨论。     

Quantification of mitral valve stenosis by three-dimensional transesophageal echocardiography

The aim of this study was the evaluation of the diagnostic potentials of transesophageal 3D-echocardiography in the determination of mitral valve stenosis. 54 patients were investigated by transthoracic and multiplane transesophageal echocardiography. In 41 patients cardiac catheterization was performed. 3D-echocardiographic data acquisition was performed by automatic transducer rotation at 2° increments over a span of 180°. The transesophageal probe was linked to an ultrasound unit and to a 3D-workstation capable of ECG- and respiration gated data acquisition, postprocessing and 2D/ 3D image reconstruction. The mitral valve was visualized in sequential cross-sectional planes out of the 3D data set. The spatial position of the planes was indicated in a reference image. In the cross-sectional plane with the narrowest part of the leaflets the orifice area was measured by planimetry. For topographic information a 3D view down from the top of the left atrium was reconstructed. Measurements were compared to conventional transthoracic planimetry, to Doppler-echocardiographic pressure half time and to invasive data. The mean difference to transthoracic planimetry, pressure half time and to invasive measurements were 0.3 ± 0.1 cm², 0.2 ± 0.1 cm² and 0.1 ± 0.1 cm², respectively. Remarkable differences between the 3D- echocardiographic and the 2D- or Doppler- echocardiographic methods were observed in patients with severe calcification or aortic regurgitation. In 22% of the patients the 3D data set was not of diagnostic quality. New diagnostic information from a 3D view of the mitral valve could be obtained in 69% of the patients. Thus, although image quality is limited, 3D- echocardiography provides new topographic information in mitral valve stenosis. It allows the use of a new quantitative method, by which image plane positioning errors and flow-dependent calculation is avoided.     

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.     

超声心动图对二尖瓣狭窄瓣膜置换术后血流动力学改变的研究

目的 应用彩色多普勒超声心动图了解二尖瓣狭窄患者接受二尖瓣置换术(MVR)前、后血流动力学改变情况。方法 回顾性分析37例二尖瓣狭窄患者接受MVR前、后左房内径、三尖瓣反流速率、肺动脉收缩压(PAPS)及左室射血分数改变情况，并进行PAPS与二尖瓣跨瓣压差(MV△P)间相关性分析。结果 所有患者术后均健康存活，平均随访15．8个月。随访结果：MVR后左房内径、三尖瓣反流速度及PAPS均较术前显著下降，而左室射血分数则较术前显著上升。PAPS与MV△P间呈显著正相关，且随PAPS升高，PAPS与MV△P差值亦显著升高。结论MVR能有效地改善二尖瓣狭窄血流动力学，PAPS与MV△P呈正相关，重度肺动脉高压患者肺循环内存在二级狭窄。     

近端等速表面积法测量二尖瓣狭窄瓣口面积的研究

目的　探讨近端等速表面积法 (PISA)和近端球缺表面积法 (PSSA)测量二尖瓣狭窄 (MS)瓣口面积(MVA)的准确性。方法　 2 0例接受瓣膜置换术及 3 0例非手术的MS患者 ,应用PISA、PSSA、二维超声心动图法 ( 2DE)及压差减半时间法 (PHT)法测量MVA。结果　① 4种超声方法均与手术直接测值 (aMVA )高度相关 ;② 2DE法高估了aMVA ,PSSA、PHT、PISA法与aMVA无显著性差异。③PISA法高估了PSSA法 ,但无显著性差异。结论　PISA和PSSA测量MVA均有一定的准确性 ,但PISA法轻度高估MVA ,PSSA法具有更高的临床应用价值。     

"纽扣状"转移保留二尖瓣全装置瓣膜置换及其对左心功能的影响

目的：探讨风湿性心脏病二尖瓣病变以狭窄为主的病人采用“钮扣状”转移保留全瓣装置二尖瓣置换的方法及对左心功能的影响。方法：对80例二尖瓣狭窄需行二尖瓣置换的患者，分为：A组(术中“钮扣状”保留全部二尖瓣瓣下结构)．B组(术中仅保留二尖瓣后瓣及瓣下结构)和C组(术中未保留瓣下结构)；术前、术后3～6个月行超声心动图检查。结果：A组术后左室舒张末（LVEDV）、收缩末（LVESV）容积，左室射血分数(LVEF)、短轴缩短率（LVFS）的改善优于B、C组，对于射血分数的改善A组显著优于B、C组。A、B组主动脉阻断时间较C组延长，但A、B两组无显著差异。总体转流时间C组较A、B两组缩短。结论：风湿性心脏病以二尖瓣狭窄为主的病人行瓣膜置换时可采用“纽扣状”转移保留全部瓣下装置；病人术后早期心功能的改善优于部分保留组和不保留组。     

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。     

二尖瓣对合高度指数评估二尖瓣成形术成形效果可行性

目的评价二尖瓣对合高度指数评估二尖瓣成形术成形效果的可行性。方法我院因单纯二尖瓣脱垂行二尖瓣成形术患者11例,术后复跳即刻二尖瓣反流面积为2～4cm2。二尖瓣成形术前、术后复跳即刻、术后1周测量并计算患者二尖瓣A1-P1区、A2-P2区、A3-P3区对合高度指数。术后复跳即刻、术后1周定量描记患者二尖瓣反流量。结果 11例患者除1例术后即刻出现大量反流(≥8cm2)行二尖瓣置换术外,其余10例均完成二尖瓣成形术。10例患者二尖瓣对合高度指数术前分别为:A1-P1区(15.1±13.0)%,A2-P2区(5.7±9.3)%,A3-P3区(6.4±9.4)%;术后复跳即刻分别为:A1-P1区(37.7±9.6)%,A2-P2区(43.1±6.4)%,A3-P3区(35.8±7.0)%;术后1周分别为:A1-P1区(41.1±7.9)%,A2-P2区(43.1±7.4)%,A3-P3区(36.7±6.9)%。10例患者术后复跳即刻二尖瓣各区域对合高度指数与术前比较差异均有统计学意义(t值分别为4.4、10.5和7.9,P均<0.05),但与术后1周比较差异均无统计学意义。10例患者二尖瓣反流量术后复跳即刻为(2.84±0.44)cm2,术后1周为(0.70±0.42)cm2,差异有统计学意义(t=12.89,P<0.05)。结论超声心动图测量二尖瓣对合高度指数可行。二尖瓣对合高度指数可作为一项超声定量指标即时评价二尖瓣成形术成形效果。     

Parachute mitral valve: Echocardiographic findings resembling idiopathic hypertrophic subaortic stenosis

The echocardiographic features recorded in a patient with a congenital anomaly, single papillary muscle (parachute mitral valve), were identical with those seen in patients with idiopathic hypertrophic subaortic stenosis (IHSS). Asymmetric septal hypertrophy, mitrai valve systolic anterior movement, aortic valve vibration, and midsystolic reclosure were all demonstrated. This congenital anomaly should, therefore, be considered in any young paitent before making the diagnosis of IHSS from the echocardiogram.