THE RIGHT HEART Casey Buckingham Advanced Clinical Physiologist

Aims

To explain the normal Right Heart anatomy & Abnormalities that occur.

To review relevant measurements, calculation & new BSE (2008) /ASE (2010) guidelines.

Abnormalities

Pulmonary Valve Disease

Tricuspid Valve Disease

Ebstien’s Anomaly

Carcinoid

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

Normal Right Heart

Pyramid shape divided into Inflow (Base) and Outflow (Sides)

Inflow and Outflow separated by Crista Supra Ventricularis

Crescent shape in cross section seen to wrap around the LV

Right Ventricle

Thinned wall (<5mm) and smaller than left (~ 0.6)

Tricuspid valve more apically displaced than Mitral ( up to 1cm)

Inner walls irregular and are lined by small bundles of muscles called Trabeculae Caunae

Large muscle band noted at Apex Moderator Band

Coronary Artery Supply to Right Heart

RV Dimension Apical 4ch (BSE 2008) Basal RV dimension(RVD1)

Normal 2 – 2.8cm Mild 2.9 – 3.3cm Mod 3.4 – 3.8cm Severe > 3.9cm

Mid RV dimensions (RVD2)

Normal 2.7 – 3.3cm Mild 3.4 – 3.7cm Mod 3.8 – 4.1cm Severe >4.2cm

Base to Apex (RVD3)

Normal 7.1 -7.9 Mild 8 – 8.5 Mod 8.6 – 9.1 Severe >9.2cm

RV Apical 4ch Measurements

RVOT Diameters SAX (BSE 2008) RVOT at AOV level (RVOT 1)

Normal 2.5 – 2.9cm Mild 3 – 3.2cm Mod 3.3 – 3.5cm Severe >3.6cm

RVOT at PV annulus (RVOT2)

Normal 1.7 – 2.3cm Mild 2.4 – 2.7cm Mod 2.8 – 3.1cm Severe >3.2cm

Main PA diameter (PA1)

Normal 1.5 – 2.1cm Mild 2.2 – 2.5cm Mod 2.6-2.9cm Severe >3cm

RV Para-sternal SAX Measurements

RV Dilation Mild – Increased 60 to 100 % of LV

Moderate – Equal to LV

Severe – Exceeds LV

RV Systolic Function

• Assessment similar to LV :

• ‘’Eyeball’’

• RWMA – Normal/Hypo/Dys/Akinetic

• TAPSE – Normal 16 – 20mm

Mild 11 – 15mm

Mod 6 – 10mm

Severe < 5mm

RV TAPSE

Distance of systolic excursion along the longitudinal plane at peak systole

Assessment of RVH Normal <5mm

Right Atrium

Assists in the filling of the RV.

Thinned walled with relatively smooth body.

Retrosternal – sometimes difficult to image.

RAA trabeculated, broad based & triangular in shape (seldom seen on TTE)

Dimensions roughly similar to LA.

RA Normal Variants

Crista Terminale.

Eustachian Valve.

Chiari Network.

RA Dimensions

Primary TTE window to assess RA size Apical 4ch.

Maximal long axis distance – centre of Annulus to centre of the Superior wall.

Mid minor distance – Mid level of the Anterolateral wall (Free wall) to the IA septum, perpendicular to the long axis.

Upper reference limits are 4.4cm & 5.3cm

RA Dimensions

RA Area

Measure end systole = largest volume.

Lateral aspect of TV annulus to the Septal aspect – follow endocardium

Excluding IVC/SVC & RAA

Good indicator for RV diastolic dysfunction.

Should be applied in the assessment of RV or LV dysfunction.

Upper reference limit of 18cm2

Tricuspid Valve

• Annulus apically displaced 1cm

• Septal, Anterior, Posterior (which is also the Inferior or medial, depending which books you read!!!)

• Open of the TV precedes opening of the MV.

• Varies with inspiration, measure over 4 – 5 beats.

• Normal velocities 0.4 to 0.8m/s

Causes of TR

• Rheumatic – 20 to 30 % near always occurring with MV or +/- AOV disease.

• Prolapse – associated with Marfans & MVP

• Congenital - Ebsteins.

• Endocarditis – IVDU.

• Carcinoid – Free flowing, low velocity.

• Functional – Annular dilation due to PHT caused by left sided problems *Most common*

• Physiological – Mild TR seen in 75% of healthy individuals.

Classification

• Mild – Flow disturbance in sys localized to area adjacent to TV closure plane <5cm2

• Moderate – Fills between 5 – 10 cm2 of RA

• Severe - >10cm2 of a dilated RA with IVC & SVC systolic flow reversal. Vena contracta width >0.7cm (89% sensitive 93% specific)

• Vena contracta – Moderate <0.7cm & Severe >0.7cm.

TR Doppler Profile

• Maximum velocity = Maximum pressure difference across the TV NOT severity of regurgitation.

• Severe TR + Normal RVSP = Low velocity.

• Mild TR + PHT = High max velocity

• Intensity of CW = Regurgitant severity.

• Curve = time of instantaneous pressure difference across TV

Measurements Obtainable

• Systolic Pulmonary Pressure – PA pressure or RVSP

• Measure Peak TR velocity

• Apply simplified Bernoulli equation

• Then add estimated RA pressure (IVC)

• RVSP = 4 (vTR) 2 + RAP

• **In absence of RVOT /Pulmonary obstruction**

RVSP/PA Pressure

Assessment of RAP

• Assess in sub-costal view.

• End expiration.

• Proximal to junction of hepatic veins which lie 0.5cm to 3cm ostium of RA.

• Assess inspiratory collapse ‘’Sniff’’ – unable to perform adequate ‘’sniff’’ IVC collapse <20% with quiet inspiration = increased RAP

• **Specific values not ranges**

Assessment of RAP

PA pressure + RA pressure

Small Normal Mild Moderate Severe

18 – 25mmHg IVC <1.5cm & seen to collapse + 0-5mmHg

18 – 25mmHg IVC 1.5cm to 2.5cm & seen to collapse. Normal RA/Hepatic vein size + 5mmHg to 10mmHg

30 – 40mmHg IVC 1.5 to 2.5cm & >50% collapse. Normal RA/Hepatic vein size +5 – 10mmHg

40 – 70mmHg IVC >2.5cm with <50% collapse with dilation of RA/Hepatic veins +10 -15mmHg

> 70mmHg IVC > 2.5cm with no resp collapse & significant dilation of the RA/Hepatic veins + >20mmHg

Tricuspid Stenosis

• Nearly always Rheumatic in origin

• Usually accompanied by Mitral stenosis.

• 2D – Thickening & shortening of TVL with reduced excursion.

• Commissural fusion prevents tip separation, dissociation of tip & body results in Doming in diastole.

Doppler Assessment of TS

• Transvalvular flow velocity - Mean PG & PHT

• Use mean gradient of CW in Apical 4ch.

• Normal: TVA > 7cm2

• Moderate: Mean PG 2 to 5mmHg & TVA 7 to 1cm2.

• Severe: Mean PG >5mmHg & TVA <1cm2

Symptoms

Usually gradual onset

Systemic venous congestion leading to abdominal discomfort & swelling.

Dyspnoea may be present.

Prominent pulsation in neck – increased JVP.

Eventually leads to HF or other complications including stroke or infection.

Other Causes

• Carcinoid heart disease.

• Congenital Tricuspid Atresia

• Infective endocarditis

• RA myxoma

**All obstruct so mimic TS**

Pulmonary Valve

Tricuspid

Annulus distal to RVOT

Similar dimensions to Aortic root (develops same time as Aorta)

Not easily visualised on 2D – assess with CFM & Doppler for accurate assessment.

Normal forward flow 0.7 to 1.4m/s

Pulmonary Stenosis

• Most often congenital , 7.6% of CHD

• May occur with other congenital lesions – ccTGA & TOF

• Mild PS may be asymptomatic but if occur include; SOB, CP, fainting or exertional syncope & sudden death

• 2D – thickening of leaflets with systolic bowing

• Doppler – 4v2 **PVA not suggested**

PS (BSE 2008)

Mild Moderate Severe

< 40 mmHg 40 – 75mmHg >75mmHg

Pulmonary Regurgitation

• Incidental, benign finding in most normal individuals.

• Congenital PVD – mild untreated or residual after surgery

• Common complication post surgical or percutaneous relief of PS.

• Secondary to dilation of PV ring due to PHT or Marfan’s.

• Leads to progressive RV dilation & dysfunction, VT & sudden death.

Assessment

• Diastolic flow in RVOT

• Width of flow –semiquantive index of severity

• Holodiastolic flow reversal may be noted in MPA

• Even if only mild, peak velocity reflects the PA to RVDP difference.

PR (BSE 2008)

Jet size CFM (cm)

Mild - Narrow <1cm Mod – Intermediate Severe – Wide, large.

CW jet / Deceleration rate

Mild – Soft/Slow Mod – Dense/Variable Severe – Dense / Steep.

Regurg Fraction (%)

Mild - <40% Mod – 40 to 60% Severe - >60%

Ebstein’s Anomaly

Congenital defect

One or more TVL are Apically displaced, most often the septal leaflet

Degree of displacement varies >1cm.

Functional TR & enlarged RH

Atrialization of RV

ASD & WPW frequently associated.

Adult Presentation

Fatigue

Exertional dyspnoea

Cyanosis

TR and / or RHF

Palpitations

Carcinoid

Release of 5HAA from hepatic metastases Incidence of approx 1 in 75,000 Slow growing, usually up to 20 years or more

before symptoms develop. Typically occurs in 5th – 7th decade of life. Cardiac involvement occurs in 50% of

patients – worsens prognosis & contributes significantly to morbidity & mortality.

Usually only tumours that invade the liver result in pathological changes of the heart

Carcinoid Heart Disease

• Fibrous deposits on endocardium of RH interfacing with the myocardium & (R) sided valves.

• Valves are thickened & retracted, eventually becoming immobile & remain in a semi open position ‘’drumstick’’ appearance

• Free flow TR – short abrupt asymmetrical Doppler due to reduced time to Peak velocity.

• Dilated & overloaded RH

• Results in RHF

Treatment

Surgical intervention.

Regular follow up

Peri operative mortality around 35%

ARVC

Infiltrative cardiomyopathy. Male to Female 3:1 ratio After HOCM next cause in SCD in young

persons (5% in < 65yr-olds) Progressive replacement of normal

myocardium with fatty infiltration either Adipose or Collagen.

LV & IV septum may be affected. Hereditary 3 phases : Concealed - Electrical - Failure.

Echo Features

• Dilation & global dysfunction of RV.

• Localised aneurysmal bulges of outflow or inflow tracts which are thinned & akinetic.

• Thickened, hyper reflective moderator band

• Normal or mildly impaired LV.

• New criteria – Increased Anteroposterior diastolic dimension of outflow tract in (PLAX) >3cm

Symptoms

Abdominal pain.

Fatigue.

Reduced ET with SOBOE

Dizziness.

Palpitations.

Syncope.

Test

Echo.

MRI – Gold standard non – invasive diagnosis.

Endomyocardial biopsy.

Contrast echo – to identify aneurysmal segments.

Treatment

Antiarrhythmic & anticoagulation drugs.

ICD – primary prevention.

RFA.

Cardiac transplant.

Pressure Overload

Acute rise in Pulmonary vascular resistance

Pulmonary valve or RVOT obstruction.

Increased Left sided pressures = increase PA pressures.

RV free wall & Septal hypertrophy.

Exaggerated Septal motion in systole - Concaved/flattened IV septum in systole

Volume Overload

• Dilation of RV

• Paradoxical septal motion ‘’D’’ shaped in diastole.

• Augmentation of systolic function

• LV systolic & diastolic impairment.

• Septal hypertrophy = LV compliance.

• Left to right shunts = 30%

• Pure volume overload well tolerated.