# 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

Mild	Moderate	Severe
< 4cm²	4-10cm²	> 10cm²

# Jet area : Left atrium

$\frac{\text{Jet area}}{\text{Left atrial area}} \times 100$

Influenced by: 受很多因素影响
- 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

Mild	Moderate	Severe
＜ 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，反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

Mild	Severe
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）

Mild		Severe
< 3mm	If 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

Normal	Severe
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 MR	Severe MR
A wave dominant A 波占主导	E/A ratio > 1.4 E wave > 1.5 m/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

Mild	Moderate	Severe
< 0.4cm	0.4 - 1.0cm	> 1.0cm

# Effective Regurgitant Orifice Area 有效反流口面积

PISA Equations

$\text{PISA Surface Area} (cm^{2}) = 2 \times \pi \times r^{2}$

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

$\text{EROA} (cm^{2}) = \frac{\text{Regurgitant Flow}}{\text{MR Max velocity}}$

Mild	Moderate	Severe
< 0.2 cm²	0.2 - 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

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

Mild	Moderate	Severe
< 30ml	31-59ml	≥ 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
$\text{MV area} \times \text{MV VTI} = \text{LVOT area} \times \text{LVOT VTI}$
每搏量计算
$\text{Stroke Volume (Mitral)} = \text{MV cross sectional area} \times \text{MV VTI}$
$\text{Stroke Volume (LVOT)} = \text{LV cross sectional area} \times \text{LVOT VTI}$
$\text{cross sectional area (CSA) 横截面积} = 0.785 \times (diameter)^{2}$
If there is no MR,
$\text{SV (MV)} = \text{SV (LVOT)}$
Regurgitant Volume 反流容积计算
$\text{Regurgitant Volume} = \text{SV (MV)} - \text{SV (LVOT)}$

Mild	Severe
< 30ml	≥ 60ml

Regurgitant Fraction 反流分数计算
$\text{Regurgitant Fraction (\%)} = \frac{\text{Regurgitant Volume}}{\text{SV (Mitral Valve)}}$

Mild	Moderate	Severe
< 30%	31-49%	≥ 50%

EROA 有效反流口面积
$\text{EROA} = \frac{\text{Regurgitant Volume}}{\text{MR VTI}}$

Mild	Moderate	Severe
< 0.2cm²	0.2 - 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, SV_MV was 183 mL (d = 3.5 cm, velocity time integral =19 cm) and SV_LVOT 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，SV_MV 为 183ml（d=3.5cm，速度时间积分 = 19cm），SV_LVOT 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。

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

Normal	Mild	Moderate	Severe
16-28ml	29-33ml	34-39ml	≥ 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。