# Learning objectives

  • How to assess MR Severity
    如何评估 MR 严重程度
  • Colour Flow measures
    彩色血流
  • Doppler methods of MR assessment
    多普勒
  • PISA/flow convergence and limitations
    近端等速表面积 / 血流收敛方法及其局限性
  • Volumetric assessment and limitations
    容量评估及其局限性
  • Role of special tests in MR
    其他特殊检测在 MR 中的作用

# How to Assess MR Severity

  • Anatomic: valve structure, LA / LV dimensions
    解剖:观察瓣膜结构,左房左室大小
  • semi-quantitative methods 半定量方法
    • Colour Flow Mapping
      彩色血流
    • Jet area and Jet area / Left atrium ratio
      观察反流面积,以及反流面积与左房的比值
    • Vena contracta width
      缩流颈宽度
  • Quantitative methods
    定量方法
    • PISA/flow convergence technique 血流汇聚技术
    • Continuous wave doppler 连续波多谱勒
    • Pulmonary vein flow reversal 肺静脉血流逆转
    • Doppler volumetric method 多普勒容积法
    • Pulsed wave E' 脉冲多普勒

# Qualitative / Semi-quantitative methods 定性 / 半定量方法

# Colour Flow

Eyeball grading of colour jet in mitral regurgitation
二尖瓣反流中彩色射流的目测法分级
Mild轻度1+
Moderate中度2+
Moderate to severe中重度3+
Severe重度4+
  • Assessed in PLAX, A4C, A3C, A2C
    在胸骨旁长轴、心尖四腔心、心尖三腔心、心尖两腔心
  • colour flow mapping(CFM) over left atrium
    在左房加持彩色多普勒
  • Small central jet in mild MR
    轻度反流为小而中心性的反流束
  • Broad central or eccentric jet with coanda effect in severe MR
    严重二尖瓣反流则多为具有柯恩达效应(沿物体表面的高速气流在拐角处能附于表面的现象)的宽的中心性或偏心性反流束
  • Colour flow methods are only for diagnosing MR and are not for MR quantification
    彩色血流法仅用于 MR 诊断,不适用于 MR 定量

# Jet area 反流束面积

  • Apical 4 chamber
    心尖四腔心
  • Nyquist limit 50-70cm/s
    尼奎斯特极限
  • Planimetry around MR jet
    对反流束进行平面描绘
  • Underestimates eccentric jet and overestimates central jet
    低估偏心性反流或小反流,高估中心性反流
MildModerateSevere
< 4cm24-10cm2> 10cm2

# Jet area : Left atrium

Jet areaLeft atrial area×100\frac{\text{Jet area}}{\text{Left atrial area}} \times 100

  • Influenced by: 受很多因此影响
    • Hypotension 低血压
    • Acute MR - underestimate
      急性二尖瓣反流 - 低估
    • Eccentric jet - underestimate
      偏心性反流 - 低估
    • Colour gain
      色彩增益
    • Nyquist limit
      尼奎斯特极限
MildModerateSevere
< 20%20% - 40%> 40%

# Continuous Wave at MR jet 反流束连续波多普勒

  • Assessed in A4C or A2C
    在心尖四腔心或心尖两腔心评估
  • CW at MR jet
    在二尖瓣反流束上放置连续波多普勒
  • Qualitative approach
    定性方法
  • Difficult to obtain if eccentric jet.
    如果是偏心性反流,则很难获得

  • Three examples of various degrees of mitral regurgitation (MR), mild (A), moderate (B), and severe (C) are provided.
    三个不同程度的二尖瓣返流 (MR) 的例子:轻度 (A)、中度 (B) 和重度 (C)。
  • The regurgitant jet as well as the mitral E wave velocity increase with the severity of MR.
    二尖瓣反流及二尖瓣 E 峰速度随 MR 严重程度的增加而增大。
  • In severe MR, the continuous wave Doppler signal of the regurgitant jet is truncated, triangular and intense.
    在重度 MR 时,回流的连续波多普勒信号被截断,呈三角形且信号灰度较强。
  • Notching of the continuous wave envelope (cut-off sign) can occur in severe MR.
    重度 MR 中可能会发生连续波轮廓的缺口 (切断征象)。
  • TVI, time-velocity integral. 时间 - 速度积分
MildSevere
  • soft density 密度较小
  • incomplete envelope 频谱边缘不完整
  • dense with triangular shape 密集,灰度较高,呈三角形
  • the "cut-off sign" 切断征象

# Vena Contracta 缩流颈

  • PLAX or A4C
    胸骨旁长轴 或 心尖四腔心切面
    • Remember: A2C is not recommended for this technique as it over estimates VC.
      记住:心尖两腔心切面不推荐用于 VC 测量,因为会导致结果高估
  • Zoom in on mitral valve
    放大二尖瓣
  • CFM at mitral valve
    在二尖瓣加持彩色多普勒
  • Nyquist limit 50-60cm/s
    尼奎斯特极限
  • Measure narrowest portion of jet as it emerges from the orifice
    当反流束从反流口喷射出来时,测量反流束最窄的部分
  • More accurate for central MR
    对于中心性 MR 更准确,偏心性反流有时不太容易看到
  • Can be used in multiple jets
    可用于多束反流
    • 缩流颈宽度 VCW = 低估,不能相加(3D 计算横截面积 VCA 可相加)
MildSevere
< 3mmIf intermediate then need another technique to quantify MR≥ 7mm

# Pulmonary Veins 肺静脉

  • Apical 4 chamber
    心尖四腔心
  • CW at pulmonary vein
    在肺静脉放置连续波多普勒
  • Influenced by LA pressure and diastolic function
    受左房压力和舒张功能的影响
  • Not accurate in atrial fibrillation
    房颤时不准确
NormalSevere

S (systolic wave) > D (diastolic wave)
S (收缩波)> D (舒张波)

Retrograde flow during ventricular systole
心室收缩时出现逆向血流

# Mitral Inflow Pattern 二尖瓣血流频谱

  • Apical 4 chamber
    心尖四腔心测量
  • Pulsed wave doppler at MV annulus
    在二尖瓣瓣环处放置脉冲波多普勒
  • Affected by LA pressure and diastolic function
    受左房压力和舒张功能的影响
  • Not accurate in AF
    房颤时不准确

  • (A) Pulsed Doppler of normal mitral inflow characteristically shows an early diastolic E-wave followed by the atrial A wave.
    正常二尖瓣血流的脉冲多普勒表现为舒张期早期 E 波,然后是房性 A 波。
  • (B) In severe mitral regurgitation (MR), marked E-wave dominance is seen (>1.2 m/s), reflecting a marked increased in early diastolic flow—typical of severe MR.
    在重度二尖瓣反流中,可见明显的 E 波优势 (>1.2m/s),反映早期舒张期血流明显增加 -- 这是重度 MR 的典型表现。
Excludes severe MRSevere MR

A wave dominant
A 波占主导

  • E/A ratio > 1.4
  • E wave > 1.5cm/s
  • DT < 150ms

# Quantitative methods 定量方法

  • Effective Regurgitant Orifice Area (EROA)
    有效反流口面积(EROA)
  • Regurgitant Volume
    反流容积
  • Regurgitant Fraction
    反流分数
  • Can be assessed using:
    可以使用以下方法进行评估:
    • PISA / flow convergence or doppler volumetric method
      近端等速表面积 / 血流收敛方法或多普勒容积法
  • These methods can help in intermediate MR patients
    这些方法可以诊断中度 MR 患者

# PISA Method

# Proximal Isovelocity Surface Area (PISA) Radius 近端等速表面积 (PISA) 半径

  • PISA 是液体流过圆形孔口时发生的一种现象。血流在开口附近收敛并加速 (Flow Convergence),血流剖面逐渐形成多层的半球形状,每层内的流速相等。

  • PISA 位于反流口近端,本身是半球形,在 2D 下看显示为半圆形,其半径是从颜色混杂的边缘到缩流颈的距离。

  • Measure from the vena contracta to first aliasing threshold
    测量从缩流颈到第一个混叠阈值的距离

  • Apical 4 chamber
    心尖四腔心

  • Zoom at MV leaflets
    放大二尖瓣瓣叶

  • Baseline to 30-40cm/s
    彩色速度基线需朝反流方向调整至 30-40 cm/s

    • TTE:朝下;TEE:朝上
MildModerateSevere
< 0.4cm0.4 - 1.0cm> 1.0cm

# Effective Regurgitant Orifice Area 有效反流口面积

  • PISA Equations

PISA Surface Area(cm2)=2×π×r2\text{PISA Surface Area} (cm^{2}) = 2 \times \pi \times r^{2}

Regurgitant Flow(ml/sec)=PISA surface area×aliasing velocity 混叠速度\text{Regurgitant Flow} (ml/sec) = \text{PISA surface area} \times \text{aliasing velocity 混叠速度}

EROA(cm2)=Regurgitant FlowMV Max velocity\text{EROA} (cm^{2}) = \frac{\text{Regurgitant Flow}}{\text{MV Max velocity}}

MildModerateSevere
< 0.2 cm20.2 - 0.39 cm2≥ 0.40 cm2

  • Flow convergence pattern differs depending on the aetiology of MR
    因 MR 病因不同,血流会聚模式存在不同
    • Functional MR (hemielliptic)
      功能性 MR(呈半椭圆形)
    • Organic MR (hemispheric)
      器质性 MR(呈半球形)
  • European guidelines have a different cut off for EROA to account for this:
    欧洲指南对 EROA 的参考范围有所不同
    • Severe functional MR ≥ 20 mm2
    • Severe primary MR ≥ 40 mm2

# Regurgitant Volume 反流容积

Regurgitant Volume=EROA×MR VTI (cm)\text{Regurgitant Volume} = \text{EROA} \times \text{MR VTI (cm)}

MildModerateSevere
< 30ml31-59ml≥ 60ml

# Limitations to PISA Method 方法的局限性

  • Assumes the EROA is constant throughout systole
    假设 EROA 在整个收缩期间是恒定的
  • Assumes EROA is hemispheric in shape
    假设 EROA 为半球形
  • PISA method more accurate for organic MR
    PISA 法对器质性病变更准确
    • Rheumatic MR - Constant PISA radius
      风湿性二尖瓣反流 - PISA 半径恒定
    • Mitral valve prolapse - PISA radius increases progressively and peaks around mid-systole
      二尖瓣脱垂 - PISA 半径逐渐增大并在收缩中期达到峰值
    • Functional MR - Early systolic peak with mid systolic decrease and late systolic peak (bimodal)
      功能性 MR - 收缩早期即达到峰值,收缩中期下降,收缩晚期再次达到峰值 (双峰)

# Volumetric Method 容积法

# Continuity equation 连续方程式

  • Assumes that there is no significant AR.
    假设不存在严重的主动脉瓣反流

    MV area×MV VTI=LVOT area×LVOT VTI\text{MV area} \times \text{MV VTI} = \text{LVOT area} \times \text{LVOT VTI}

  • 每搏量计算

    Stroke Volume (Mitral)=MV cross sectional area×MV VTI\text{Stroke Volume (Mitral)} = \text{MV cross sectional area} \times \text{MV VTI}

    Stroke Volume (LVOT)=LV cross sectional area×LVOT VTI\text{Stroke Volume (LVOT)} = \text{LV cross sectional area} \times \text{LVOT VTI}

    cross sectional area (CSA) 横截面积=0.785×(diameter)2\text{cross sectional area (CSA) 横截面积} = 0.785 \times (diameter)^{2}

  • If there is no MR,

    SV (MV)=SV (LVOT)\text{SV (MV)} = \text{SV (LVOT)}

  • Regurgitant Volume 反流容积计算

    Regurgitant Volume=SV (MV)SV (LVOT)\text{Regurgitant Volume} = \text{SV (MV)} - \text{SV (LVOT)}

MildSevere
< 30ml≥ 60ml
  • Regurgitant Fraction 反流分数计算

    Regurgitant Fraction (%)=Regurgitant VolumeSV (Mitral Valve)\text{Regurgitant Fraction (\%)} = \frac{\text{Regurgitant Volume}}{\text{SV (Mitral Valve)}}

MildModerateSevere
< 30%31-49%≥ 50%
  • EROA 有效反流口面积

    EROA=Regurgitant VolumeMV VTI\text{EROA} = \frac{\text{Regurgitant Volume}}{\text{MV VTI}}

MildModerateSevere
< 0.2cm20.2 - 0.39cm2≥ 0.40cm2

# Example

  • Echo-Doppler calculations of stroke volume at the left ventricular outflow tract and mitral valve annulus sites.
    左心室流出道和二尖瓣环处每搏量的超声多普勒计算。
    左室长轴,收缩早期,LVOT 测径线,并放置 PW 描绘频谱获得 LVOT VTI。
    四腔心,舒张中期,测二尖瓣瓣环直径 + 在测量径线的位置放置 PW 描绘 二尖瓣 E 峰和 A 峰获得 VTI

  • In this example of severe mitral regurgitation, SVMV was 183 mL (d = 3.5 cm, velocity time integral =19 cm) and SVLVOT was 58 mL (d = 2.3 cm, velocity time integral =14 cm).
    在这个严重二尖瓣反流的例子中,SVMV 为 183ml(d=3.5cm,速度时间积分 = 19cm),SVLVOT 为 58ml(d=2.3cm,速度时间积分 = 14cm)。

  • This yielded an regurgitant volume of 125 mL and a regurgitant fraction of 125/183 or 68%.
    这产生了 125 mL 的反流容量和 125/183 或 68% 的反流分数。

  • d: Diameter of the annulus, PW: Pulsed wave Doppler
    D:瓣环直径,PW:脉冲多谱勒

# Limitation

  • Time-consuming 耗时
  • PISA is first line method in quantifying MR
    PISA 是量化 MR 的一线方法
  • Potential errors due to multiple measurements
    推导过程中的多次测量可能导致潜在误差
  • Accurate resolution of the MV annulus is needed
    需要对 MV 瓣环进行准确的分辨

# Left Ventricle

  • Compensated phase: 代偿阶段
    Stroke volume is maintained through an increase in LV EF (hyperdynamic LV> 65%)
    通过增加 LV EF (高动力左室> 65% ) 来维持每搏量

  • Decompensated phase: 失代偿阶段
    Stroke volume decreases and LA pressure increases - LV function may be low normal range
    每搏量减少,左房压力升高 —— LV 功能可能正常偏低

# Left Atrium

  • LA dilates in response to chronic volume and pressure overload
    左房扩张是对慢性容量和压力超负荷的反应
  • Normal sized LA not associated with significant MR, unless it is acute
    正常大小的 LA 与严重 MR 无关,除非 MR 是急性的
  • LA dilatation predicts increased risk of AF
    左房扩张预示房颤风险增加
  • MV repair or replacement leads to reverse remodelling of the LA
    MV 修复或置换可使 LA 逆重塑

Left Atrial Volume
A significantly dilated left atrium is a predictor for worse outcomes in organic severe MR.
左心房明显扩张是器质性重度 MR 预后较差的预测指标。

Volume=0.85×LA areaA4C×LA areaA2CLength of LA (AP length in A4C)Volume = \frac{0.85 \times \text{LA area}_{A4C} \times \text{LA area}_{A2C}}{\text{Length of LA (AP length in A4C)}}

NormalMildModerateSevere
16-28ml29-33ml34-39ml≥ 40ml

# Pulmonary Artery Systolic Pressures 肺动脉收缩压

  • Excess mitral regurgitant flow entering the LA causes increase LA pressure
    进入左房的二尖瓣返流过多导致左房压力升高

  • This results in a raised pulmonary pressure
    这导致肺动脉压升高

  • TR max gradient + RAP (IVC size and collapsibility) to estimate pulmonary pressures.
    TR 最大压差 + RAP(下腔静脉大小和收缩性)以估计肺压力。

  • PASP > 50mmHg at rest is an indication for MV repair
    静息时 PASP >50 mmHg 是 MV 修复的指征

# Special tests in MR 其他特殊手段

# Exercise Echocardiography 运动负荷超声心动图

  • Useful in asymptomatic patient with severe organic MR and borderline EF (60-65%)
    适用于无症状的严重原发性 MR 伴临界 EF(60-65%)的患者
  • If there is an absence of contractile reserve it could identify patients at risk of cardiovascular events
    如果没有很好的收缩储备,可认为患者有较高的心血管事件风险
  • Equivocal symptoms out of proportion of MR severity
    可疑症状与 MR 严重程度不成比例时用作参考
    • PASP > 60mmHg on exercise is an indication for Mv repair.
      运动时 PASP > 60 mmHg 为 MV 修复的指征

# 3D Echocardiography

  • Provides improved definition of mitral morphology
    改善了二尖瓣形态的显示

# Summary

  • The main methods (anatomical, semi-quantitative and quantitative) for assessment of mitral regurgitation
    评估二尖瓣反流的主要方法(解剖学、半定量和定量)
  • The advantages and limitations of each of these methods
    每种方法的优点和局限性
  • The need to integrate information from each of these to reach a final assessment of mitral regurgitation severity
    需要综合这些信息以得出二尖瓣反流严重程度的最终评估
  • A brief discussion of more advanced techniques
    简要讨论了更先进的技术。