# Learning Objectives

  • RV anatomy, haemodynamics and contractility
    右室解剖、血流动力学和收缩性能
  • Ventricular interdependence
    心室相互依赖
  • Basic views of the RV
    右室的基本切面
  • Dimensions and thickness of the RV
    右室的尺寸和厚度
  • Assessing RV function - tricuspid annular plane systolic excursion(TAPSE), fraction area change(FAC), tissue Doppler imagings(TDI) S' and Tei index
    评估右室功能 - 三尖瓣环平面收缩期偏移、面积变化分数、组织多普勒成像和心肌做功指数
  • Assessing RV systolic pressure
    评估右室收缩压,从而评估肺动脉的压力
  • RV strain - not routine
    了解右室应变 - 不是常规
  • Limitations of RV function assessments
    右室功能评估的局限性

# RV anatomy, haemodynamics and contractility

# Right Ventricle Anatomy 右室解剖

  • Anterior to the LV and posterior to the sternum
    右室位于左室前面和胸骨后面
  • Thin walled and compliant chamber
    室壁薄,心腔顺应性强
  • Asymmetrical and crescent shaped
    不对称和新月形
  • Divided into inflow tract, infundibulum (outflow) and the apex
    分为流入道、漏斗部(流出道)和布满肌小梁的心尖部
  • Three muscular bands: Parietal, septomarginal and the moderator band.
    解剖学上可以看到三种肌束:位于腔壁的、隔缘的和隔缘肉柱(节制带)。

# RV Coronary Supply 右室冠脉血供

  • Coronary flow maintained throughout cycle due to low intraventricular pressure
    由于右心室内压低,冠状动脉血流在整个心动周期内都保持
  • Hence effect of decreased diastolic perfusion in tachycardia does not affect RV perfusion as much as it affects the LV
    因此,心动过速时,舒张期冠脉灌注降低的影响对右室灌注的影响不如对左室的影响大
  • RV free wall and posterior third of septum - supplied by the RCA
    RV 游离壁和后三分之一的间隔 - 由 RCA 供血
  • Apex and anterior 2/3 of septum - supplied by LAD.
    心尖部和前 2/3 的间隔 - 由 LAD 供血

# RV Contractility 右室收缩能力

  • RV contraction is 'peristaltic'
    右室收缩呈 “蠕动” 的形态
  • Predominantly longitudinal muscle fibres
    主要是纵向肌肉纤维
  • Three different mechanisms:
    右室收缩三种不同的机制:
    • Inward movement of the free wall
      游离壁的向内移动
    • Contraction of longitudinal fibres
      纵向纤维的收缩
    • Traction of the free wall at points of attachment secondary to LV contraction
      左室收缩后,附着点处自由壁的牵引
  • No torsion or rotational movement.
    没有扭转或旋转运动。

# Function of the Right Ventricle 右室的功能

  • Maintains adequate PA perfusion pressure to improve gas exchange
    维持足够的肺动脉压,以改善气体交换
  • Maintains a low systemic venous pressure to prevent congestion of tissue or organs
    维持较低的中心静脉压,以防止组织或器官充血
  • Impaired RV results in reduced LV preload
    右室功能受损导致左心室前负荷减少
  • Ventricular interdependence.
    心室相互依赖

# Ventricular Interdependence 心室相互依赖

  • Around 40% of RV Systolic function is attributable to LV systolic function due to ventricular interaction
    由于心室相互作用,约 40% 的右室收缩功能归因于左室收缩功能
  • Ventricular interdependence can be direct or indirect
    心室相互依赖可以是直接的,也可以是间接的
    • Direct: Via the septum and pericardium
      直接的包括:通过间隔和心包作用
    • Indirect: Via closed loop circulation i.e. RV output is equal to LV output.
      间接的包括:通过闭环循环,即 RV 输出等于 LV 输出。
Volume overload 容量过度负荷
Flattening of septum in diastole
舒张期间隔变平
Pressure overload 压力过度负荷
Flattening of septum in systole and diastole
收缩期和舒张期间隔变平

# Difficulties in Assessment 右室评估的困难点

  • Difficult to estimate RV volume due to crescent shape i.e. asymmetrical
    由于新月形,即不对称,难以估计 RV 容积
  • Difficult to estimate border due to trabeculation
    由于肌小梁的存在,很难估计心内膜的边界
  • Difficult to image as posterior to sternum
    胸骨后方难以成像
  • Difficult to image infundibulum which contains 25-30% of the RV volume.
    漏斗部占右室体积的 25%-30%,这部分难以成像。

# Basics Views of the Right Ventricle


[1]

# Dimensions and thickness of the RV

# RV inflow Dimensions

  • Diagram (left) and corresponding echocardiographic apical 4-chamber image (right) showing the right ventricular (RV) basal (RVD1) and mid cavity (RVD2) RV minor dimensions and the RV longitudinal dimension (RVD3).
    图 (左) 和相应的心尖四腔图 (右) 显示右室 (RV) 基底部 (RVD1) 和中部 (RVD2) 的 RV 最小尺寸和 RV 的纵向的长径 (RVD3)。
  • The transducer is adjusted to focus on the RV chamber, with the goal of maximizing RV chamber size.
    传感器被调整为聚焦在 RV 腔,以最大化 RV 腔的大小。
  • The RV free wall is better seen in this view, also facilitating measurements for fractional area change.
    在这张图中可以更好地看到 RV 游离壁,也便于测量面积变化分数。
RV inflow Dimensions正常参考范围
Base (RVD1) 右心室内径,基底部Below the TV annulus< 4.2cm
Mid (RVD2) 中部的Mid-RV< 3.5cm
Length (RVD3) 右心室长径Base to apex< 8.6cm

# RV outflow Dimensions

  • Measurement of right ventricular outflow tract (RVOT) dimensions at the proximal or subvalvular level (RVOT-Prox) and at the distal or pulmonic valve (RVOT-Distal) in the (A) parasternal long-axis RVOT anterior portion view, (B) basal parasternal short-axis view, and (C) parasternal short-axis of pulmonary bifurcation view.
    在 (A) 胸骨旁长轴 RVOT 前部切面、(B) 胸骨旁基底部短轴切面、(C) 胸骨旁肺分叉切面,测量右室流出道 (RVOT) 近端 / 瓣下水平 (RVOT-Prox) 和远端 / 肺动脉瓣水平 (RVOT-Distal) 的内径。
  • PA, Pulmonary artery dimension between valve and the bifurcation point.
    PA,瓣膜和分叉点之间的肺动脉内径。
RV outflow Dimensions正常参考范围
Parasternal long axisRVOT proximal in PLAX 右室流出道近端内径< 3.1cm
Parasternal short axisRVOT proximal at AV level 右室流出道近端内径< 3.6cm
RVOT distal at PV level 右室流出道远端内径< 2.8cm
PA diameter 肺动脉内径< 2.3cm

探头的位置对 RVOT 的测量影响很大,因此应该进行多个切面的测量,而不依靠单一的指标

Diagram showing the recommended apical 4-chamber (A4C) view with focus on the right ventricle (RV) (1*) and the sensitivity of right ventricular sizewith angular change (2,3) despite similar size and appearance of the left ventricle (LV).
图中显示了推荐的心尖四腔(A4C)视图,聚焦右心室(RV)(1*)和随着角度变化,右心室大小变化明显(2、3),尽管左心室(LV)的大小和外观相似。
The lines of intersection of the A4C planes (1*,2,3) with a mid left ventricular short-axis are shown above and corresponding A4Cviewsbelow.
A4C 平面(1*、2、3)与左心室中段短轴的交点如上图所示,相应的 A4C 视图如下图所示。

# RV wall thickness 右心室室壁厚度

  • Measurement of end-diastolic right ventricular wall thickness.
    舒张末期右心室壁厚度的测量。

  • (A) Subcostal 2-dimensional image of right ventricular wall.
    右室壁的剑突下二维图像。取样线与室壁呈垂直状态。

  • (B) Zoom of region outlined in (A) with right ventricular wall thickness indicated by arrows.
    放大 (A) 中线框的区域,右室壁厚度用箭头表示。

  • (C) M-mode image corresponding to arrows in (B).
    与 (B) 中的箭头相对应的 M 模式图像。

  • (D) Zoom of region outlined in (C) with arrows indicating wall thickness at end-diastole.
    放大 (C) 中概述的区域,箭头指示舒张末期的壁厚。

  • Assessed in parasternal subcostal or parasternal long axis
    剑突下或胸骨旁长轴的评估

  • Measure at level of TV chordae at R wave
    在 R 波的 TV 腱索水平测量

  • RV hypertrophy due to chronic pulmonary hypertension(PH), hypertrophic cardiomyopathy(HCM), infiltrative cardiomyopathy
    右室肥厚的常见病因:慢性肺动脉高压、肥厚性心肌病、限制型心肌病,心肌淀粉样变

RV thickness参考范围
Normal< 5mm

# Assessing RV function

# Fractional Area Change 面积变化分数

  • Examples of right ventricular fractional area change (FAC).

    Percentage FAC=100×End-diastolic area (Area ED)End-systolic area (Area ES)End-diastolic area\text{Percentage FAC} = 100 \times \frac{\text{End-diastolic area (Area ED)} - \text{End-systolic area (Area ES)}}{\text{End-diastolic area}}

  • The endocardial border is traced in apical 4-chamber (A4C) views from the tricuspid annulus along the free wall to the apex, then back to the annulus, along the interventricular septum at end-diastole (ED) and end-systole (ES).
    在舒张末期(ED)和收缩末期(ES),心内膜边界在心尖四腔(A4C)切面中,从三尖瓣环沿着游离壁到心尖,然后沿着室间隔返回瓣环。

  • Trabeculation, tricuspid leaflets, and chords are included in the chamber.
    心腔内有肌小梁、三尖瓣瓣叶和和腱索。

  • (Left) Normal subject, FAC 60%. (Middle) Moderately dilated right ventricle (RV), FAC 40%, and a markedly dilated left ventricle (LV).
    (左) 正常受试者,FAC 60%。(中) 右心室 (RV) 中度扩张,FAC 为 40%,左心室 (LV) 明显扩张。

  • (Right) Dilated RV, FAC 20%, and the LV is foreshortened as a result of optimizing the view for the right ventricular chamber.
    (右) 右室扩张,FAC 为 20%,由于优化了右室切面,LV 看起来缩短了。

  • Well correlated with RV function measured in MRI
    与 MRI 测量的右室功能相关性良好

  • Must have good RV tracing to measure FAC accurately
    RV 必须描绘良好才能准确测量 FAC

FAC参考范围
Normal32 - 60%
Mild impairment25 - 31%
Moderate impairment18 - 24%
Severe impairment≤17%

# RV Ejection Fraction 右室射血分数

# Method one: Area-length

  • Under-estimates EF - therefore, not routine
    会低估 EF - 因此,不是常规操作
  • Assumes RV is symmetrical; area×length=volume\text{area} \times \text{length} = \text{volume}
    此公式假设 RV 是对称的(但实际并不是对称的); 面积×长度=容积\text{面积} \times \text{长度} = \text{容积}
  • 胸骨旁短轴进行长度的测量
  • 用改良的心尖四腔进行面积的测量
  • 根据这个方法可以达到右室的舒张末容积和收缩末容积

EF=End diastolic volumeEnd systolic volumeEnd diastolic volume×100EF = \frac{\text{End diastolic volume} - \text{End systolic volume}}{\text{End diastolic volume}} \times 100

# Method two: Simpsons EF

  • Assumes the RV is symmetrical
    假设 RV 是对称的(但实际是不对称的)
  • Does not include the infundibulum (which may be
    25% of the RV volume)
    不包括漏斗部分的测量(可能占 RV 容积的 25%)
  • Avoid this technique for assessment of the RV.
    避免使用这种技术来评估右室,仅供了解,临床不常用

It works well for the LV as the structure is symmetrical with orthogonal view in apical 4 and apical 2chamber.
此方法适用于 LV,因为左室的结构在心尖四腔和心尖两腔中是相对对称的正交视图,但右室不一样,右室是新月形的不对称的。

# The problem

  • The RV is not symmetrical 右室是不对称的
  • Therefore, real time 3D echocardiography (RT3DE) is needed to estimate volumes accurately.
    因此,如果觉得 RVEF 有下降,除了二维超声,还应运用实时三维超声心动图 (RT3DE) 来准确估计右室容量,或 MRI 来对右室功能进行进一步评估
  • Are both functional and prognostic parameters
    右室功能对患者预后非常重要,既是功能参数又是预后参数
  • 3D Echocardiography[2]
    • More reproducible and accurate than 2D echo
      比 2D ECHO 更具重复性和准确性
    • Can give accurate volumes, ejection fraction and stroke volume
      可以给出准确的容积、射血分数和每搏量
    • Validated against cardiac MRI.
      已经经过心脏 MRI 验证[3]
正常参考范围
RVEDV (ml) 右室舒张末期容积86±21
RVEDVI (ml/m2)49±10
RVESV (ml) 右室收缩末期容积29±11
RVESVI (ml/m2)16±6
RVEF (%)67±8

# TAPSE (Tricuspid Annular Plane Systolic Excursion) 三尖瓣环平面收缩期偏移

  • Apical 4 chamber window
    心尖四腔窗
  • Degree systolic excursion of the tricuspid annulus
    三尖瓣环的收缩期偏移
  • Reproducible.
    有较好的可重复性
  • 临床上更多应用的是 TAPSE 和面积变化分数来评估右室功能
TAPSE参考范围
Normal≥ 16mm
Mild impairment13 - 15mm
Moderate impairment10-12mm
Severe impairment< 10mm

# Tei Index 心肌做功指数

  • Tei index = RV myocardial performance index (MPI)
    心肌做功指数 = 心肌综合指数(MPI),科研中常用
  • Pulse wave doppler at tricuspid valve inflow
    使用脉冲多普勒采样三尖瓣流入端,获得 PWD-MPI
  • Marker of both global systolic and diastolic function.
    反映整体收缩和舒张功能
Isovolumic contraction timeIVCT等容收缩时间
Isovolumic relaxation timeIVRT等容舒张时间
Ejection timeET射血时间

  • Schematic outlining calculation of the myocardial performance index (MPI).
    心肌性能指数(MPI)计算示意图。
  • The myocardial performance index is the ratio of the sum of the isovolumic contraction and relaxation times (IVCT, IVRT) to ejection time (ET).
    心肌性能指数是等容收缩和舒张的时间(IVCT、IVRT)之和与射血时间(ET)之比。
  • It can be calculated by subtracting ET from total systolic time (TST) as noted in the two alternate formulas.
    如两个替代公式所述,可以通过从总收缩时间(TST)中减去 ET 来计算。

Tei Index=Isovolumic contraction time - isovolumic relaxation timeEjection Time\text{Tei Index} = \frac{\text{Isovolumic contraction time - isovolumic relaxation time}}{\text{Ejection Time}}

  • (a) 从三尖瓣关闭(A 波),至下一个心动周期三尖瓣打开(E 波)的时间 [4]
  • (b) 射血时间

Tei Index=abb=ICT+IRTET\text{Tei Index} = \frac{a - b}{b} = \frac{ICT + IRT}{ET}

Tei index/MPI参考范围
PWD-MPI≤ 0.4

# Tissue Doppler Imaging (TDI): S' 组织多普勒成像

  • Assess in apical 4 chamber window
    在心尖四腔切面评估
  • Pulsed wave doppler (with TDI) in the middle of the basal segment of the RV free wall
    脉冲波多普勒 (带组织多普勒),取样容积放在右室游离壁、基底段中间,靠近三尖瓣瓣环的地方,获得 TDI-MPI
  • s' is the highest systolic velocity
    s' 是收缩期位移的最高速度

  • Scheme for measurement of time intervals used to calculate the tissue Doppler-derived myocardial performance index (TDI-MPI): [5]
    用于计算组织多普勒导出的心肌性能指数的时间间隔的测量方案
    • a, time from cessation of the a’ wave to the onset of the e’ wave;
      从 a' 波停止到 e' 波开始的时间;
    • b, the duration of the S wave;
      S 波的持续时间;
    • c, interval between the R wave and onset of the e’ wave;
      R 波与 e' 波起始点之间的距离;
    • d, interval between the R wave and cessation of the S wave;
      R 波与 S 波终点之间的距离;
    • ICT, tissue Doppler-derived isovolumetric contraction time; IVRT, isovolumetric relaxation time
      ICT,组织多普勒获得的等容收缩时间;IVRT 等容舒张时间
TDI提示右室功能正常
s'≥ 12cm/s
TDI-MPI< 0.55
  • Evidence based importance in conditions affecting RV function e.g. inferior MI affecting the RV
    影响 RV 功能的条件下基于证据的重要性,例如下壁心肌梗死对 RV 的影响
  • Limitations: 限制
    • Tricuspid valve disease (tricuspid stenosis, tricuspid regurgitation, TS / TR/ annuloplasty)
      当存在三尖瓣疾病时(三尖瓣狭窄 / 三尖瓣反流 / 瓣环成形术)对 s' 影响较大
    • Only evaluates basal segment of RV
      仅评估了右心室基底段,不能反应整体情况
    • Affected by doppler alignment
      对多普勒采样线有角度依赖,测量值不一定准确

# Assessing RV systolic pressure

# Pulmonary Artery Systolic Pressure 肺动脉收缩压

  • Pulmonary Artery Systolic Pressure = Right Ventricular Systolic Pressure
    肺动脉收缩压 = 右心室收缩压
  • TR max pressure gradient + Right atrial pressure
    = 最大三尖瓣跨瓣压差 + 右房压
    • In the absence of RVOT obstruction
      在没有右室流出道梗阻的情况下
肺动脉收缩压参考范围
Normal18 to 25 mmHg
Mild30 to 40 mmHg
Moderate40 to 70 mmHg
Severe> 70 mmHg

# TR Doppler jet 三尖瓣反流多普勒曲线

  • 2D Echocardiogram apical view with color Doppler showing severe tricuspid regurgitation, with continuous wave Doppler showing pressure gradient of 54 mm Hg across tricuspid valve [6]

  • Best assessed in parasternal RV inflow, parasternal short axis or apical four chamber.
    最好在胸骨旁右室流入道、胸骨旁短轴或心尖四腔进行评估。

  • 从多个切面获得最大的三尖瓣频谱图进行描绘。

  • 使用连续多普勒,可以在二维及彩色多普勒的指引下放置取样线,获得最清晰的、密度最高的三尖瓣反流频谱度。

  • 取最大值作为 TR 的最大反流速度。

# Bernoulli Equation 伯努利方程

  • When fluid passes through a narrow space, the velocity increases.
    当流体通过一个狭窄的空间时,速度会增加。

  • Pressure is increased before the obstruction and is low behind the obstruction.
    压力在阻塞之前增加,而在阻塞之后较低。

  • The difference between these pressures is known as the pressure gradient which can be calculate using the Bernoulli equation.
    这些压力之间的差值称为压力梯度,可以使用伯努利方程计算。

  • 简化的伯努利方程式:

    Simplified Bernoulli equation=4×(TR Vmax)2\text{Simplified Bernoulli equation} = 4 \times (\text{TR Vmax})^{2}

  • In the example above: [7]

    4×(2.64×2.64)=27.93mmHg4 \times (2.64 \times 2.64) = 27.93mmHg

    which is the pressure change between the RV and RA
    这是 RV 和 RA 之间的压力变化,也就是跨三尖瓣的压差

# Estimate Right Atrial Pressure (RAP) 右房压

  • Obtain the IVC in subcostal window
    在剑突下声窗获得下腔静脉
  • Ask the patient to sniff - mimics inspiration - and assess collapsibility of the IVC
    让病人快速吸气 - 模仿吸气,并评估下腔静脉的崩溃 / 塌陷
Size of IVCIVC size On InspirationRight atrial pressure(mmHg)
Small < 1.5cmNear total collapse0 - 5
Normal(1.5-2.5cm)Decrease > 50%5 - 10
NormalDecrease < 50%10 - 15
Dilated > 2.5cmsDecrease ≤ 50%15 - 20
Both IVC & Hepatic veins dilatedNo change> 20

# RV strain 右室应变

  • Speckle-tracking echocardiography to evaluate RV function. 斑点追踪超声心动图评估 RV 功能。 RV strain in Apical 4 Chamber [8]

  • Angle independent assessment using 2D pictures
    利用二维图像进行角度独立评估

  • Measures global and segmental function
    衡量全局和节段功能

  • The degree of change in myocardial deformation
    心肌变形的变化程度

  • Strain rate = rate of deformation over time
    应变率 = 随着时间推移的变形率

  • Not routine part of RV assessment currently.
    目前不是 RV 评估的常规部分。

正常参考值
RV global strain-24.5 ± 3.8
RV free wall strain-28.5 ± 4.8

# Caution with 2D Parameters 注意事项

  • TAPSE

    • Load and angle dependant
      有负荷和角度的依赖性
    • Assumes that the TV annulus represents the entire RV
      假设三尖瓣瓣环代表整个右室
  • FAC

    • Load dependant
      负荷依赖
    • Heavily trabeculated RV - border challenging to trace
      排除右室过多的肌小梁导致的边界难以描绘
  • Tei Index

    • Load dependant
      负荷依赖
    • Unreliable in AF
      在房颤中不可靠
    • False negatives if high right atrial pressure
      如果右房压高,则出现假阴性
  • Longitudinal Strain
    纵向应变

    • Load dependant
      负荷依赖性

  1. Rudski, L. G. et al. Guidelines for the Echocardiographic Assessment of the Right Heart in Adults: A Report from the American Society of Echocardiography. Journal of the American Society of Echocardiography 23, 685–713 (2010). ↩︎

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