AE 1.7 - Tricuspid valve/TS/TR, Pulmonic valve/PS/PI, Endocarditis

Normal tricuspid valve anatomy

• 3 leaflets

  • 1. Anterior

    • longest, largest and greatest motion

  • 2. Posterior

    • usually smallest, multiple scallops

  • 3. Septal

    • least mobile

• open during diastole

• biggest valve (6-7cm²)

• separates RA from RV

Tricuspid annulus characteristics

• little fibrous support

  • very different from mitral annulus

  • very pre/afterload dependent

• saddle-shaped, but flattens as it dilates

• dilates in the unsupported lateral and posterior directions (very flexible) 

• large valve orifice

• sits lower in the heart than MV (closer to apex)

Standard echocardiographic views used to evaluate the tricuspid valve

• PLAX RVIT

• PSAX

• A4C RV focus

• Apical reverse 4C

• SUBX 4C

Primary Tricuspid Regurgitation

Primary

• Rheumatic

• Carcinoid

• Traumatic (acute) TV rupture - due to its anterior location

• TV prolapse – isolated is rare, usually found with MVP

  • TVP best diagnosed from the PLAX view at the level of the aorta

• Iatrogenic (caused by accident)

• device leads

• endocarditis

Ebstein’s Anomaly

• Rare congenital malformation

• Failure of the developing RV leaflets to split from the inlet portion of the ventricle

• Exaggerated apical displacement of septal leaflet

• Small functional RV

• May be associated with ASD/PFO

• displacement of leaflet is > 8mm

Functional Tricuspid Regurgitation

Functional

• secondary (annular dilation)

• Left heart disease

  • LV dysfunction

• RV dysfunction

  • RV ischemia/volume overload/cardiomyopathy

  • Dilation

• Pulmonary hypertension

  • Chronic lung disease

  • Pulmonary thromboembolism, L to R shunt

• Right atrial abnormalities

  • Afib

Common causes of Tricuspid Regurgitation

most common = annular dilation (secondary)

• structurally normal TV leaflets

• results in incomplete coaptation of the TV

Causes of Tricuspid Stenosis

Congenital: 

• Rare, usually associated with other congenital cardiac defects

• Ex: maldeveloped leaflets, shortened or malformed chords, annular hypoplasia, papillary muscle abnormalities

Acquired:

• Rheumatic

  • most common cause of TS

  • TS almost never isolated, occurs with MS/AS

  • Features resemble MS (commissures fused)

• Carcinoid - valve looks stuck open

  • Caused by rare, malignant neuroendocrine tumor

  • Secretes excessive amounts of serotonin which damages TV and PV

  • Plaque-like deposits on leaflets cause the valve to become thickened, retracted and rigid

  • Creates stenosis and regurgitation

    • most common valvular issue is TR

• Other:

  • Cor triatriatum dexter

  • Large masses (TV vegetations, right heart thrombus or tumors)

Hemodynamic consequences of Tricuspid Regurgitation

• backward flow of blood from RV → RA

• volume backup into the venous system

  • flow reversal in hepatic veins & IVC

• volume overload into RV (regular + regurgitant blood volume)

• RV pressure increases

Hemodynamic consequences of Tricuspid Stenosis

• obstructed blood flow from RA → RV

• increased pressure in RA

• systemic venous congestion

• jugular vein distension

• ascites (fluid buildup)

• peripheral edema

Expected chamber remodeling with pressure overload vs. volume overload

RV volume overload

• flattening of septum during diastole

RV pressure overload

• flattening of septum during systole

Clinical findings associated with right-sided valve disease

• systemic venous congestion

• ascites

• peripheral edema

• enlarged, tender liver (congestion backup) 

• jugular vein distension

• RA dilation

• RV dilation with LV septal shift

• Dilation of inferior vena cava

• heart murmur that increases with inspiration

How Tricuspid Regurgitation is used to estimate right ventricular systolic pressure (RVSP)

RVSP = Tricuspid Regurgitation Pressure Gradient + RA pressure

Components needed to calculate RVSP

RVSP = Tricuspid Regurgitation Pressure Gradient + RA pressure

RAP = IVC size & collapsibility

Basic interpretation of calculated pulmonary pressures

normal is less than 35

severe is greater than 60

Clinical situations that may affect Doppler interrogation & alternate imaging windows (Pulmonary Hypertension & RVSP)

• The peak TR velocity does not reflect the severity of TR

  • It reflects the pressure difference between the RV and RA during systole

  • Ex. there can be mild TR and very high TR velocities or severe TR with very low TR velocities

• In Severe TR cases, this cannot accurately be estimated by using the TR velocity technique

• PLAX RVOT

• PSAX

• high PSAX

• SUBX short axis

• anterior tilt A5C

• PSAX PV

Normal pulmonic valve anatomy

• 3 components

  • annulus, cusps, commissures

• 3 cusps

  • anterior, left, right

  • not supported by IVS

• separates RVOT from PA

• most anterior & superior valve

• separated from the TV by a muscular fold

Congenital causes of Pulmonic Stenosis

• most common cause

• valvular

  • 1) Typical dome-shaped PV

    • Most common type of congenital PS

    • Preserved valve mobility, narrowed central opening, raphes

  • 2) Dysplastic (abnormally developed) PV

    • Trileaflet with deformed and thickened leaflets, poor mobility

    • Frequently associated with Noonan syndrome

  • 3) Unicuspid/Bicuspid PV

    • Fusion between commissures of leaflets

    • Bicuspid are frequently found with tetralogy of Fallot

• subvalvular (infundibular)

  • Often associated with Tetralogy of Fallot

  • May be associated with other complex congenital heart lesions

• supravalvular

  • Can be isolated or in association with tetralogy of Fallot or other syndromes such as Noonan’s

  • May result secondary to residual scarring of the MPA following removal of a PA band

• branch PA Stenosis

  • May be diffuse or single lesion

  • Often associated with other syndromes

Acquired causes of Pulmonic Stenosis

• rare – usually carcinoid or rheumatic cases

• other causes:

  • HOCM

  • Masses

  • Tumors/thrombus

Common causes of Pulmonic Insufficiency (regurg)

• Primary

  • Carcinoid

  • Congenital

  • Endocarditis

  • Rheumatic (rare)

  • Trauma (rare)

• Secondary (functional) – most common cause

  • PA dilatation

  • RV cardiomyopathy

  • RV infarct

  • PHTN

Hemodynamic effects of Pulmonic Stenosis

• RV pressure increase

• RVH & dilation

• RVEDP increases

• increased afterload

• RV failure

• pulmonary artery systolic pressure increase

Hemodynamic effects of Pulmonic Insufficiency

• backflow from PA → RV

• RV volume overload

• TV annulus dilated → TR

• RVEDP increases

• right heart failure

  • peripheral edema

• diastolic flow reversal in pulmonary branches

Expected right ventricular remodeling associated with chronic disease

PI

• RV volume overload

• RV/RA dilation

• right heart failure

• PA dilation

PS

• RVH

• RV dilates

• decrease in contractility

• RV failure

Pulmonary Artery Systolic Pressure

• In the absence of RVOT/PV obstruction: 

  • PASP = RVSP

• In the presence of RVOT obstruction (PS) use:

  • PASP = RVSP – peak PS gradient

Risk factors for infective endocarditis

• Pre-existing heart conditions

  • Acquired heart disease (ex. Rheumatic)

  • Degenerative heart disease (ex. Prolapse)

  • Congenital Heart disease (ex. Bicuspid)

  • Prosthetic Valves

• Intracardiac Devices

  • Pacemaker/ICD wires

  • LVAD

  • Catheters

• Patient Factors

  • Age >60 yrs

  • Male

  • IV drug use

  • Dental procedures

Common causative organisms

staph

strep

enterococci

Role of transthoracic echocardiography (TTE) in diagnosis

• first step

• aids in diagnosis of IE

• assess the functional abnormalities of the valve(s) affected

• assess the secondary consequences of the valvular disease

• identify complications of IE

• surveillance during and after therapy

• If pathology found:

  • assessment of the degree

  • severity of valvular obstruction and/or regurgitation

  • evaluation of chamber dimensions

  • ventricular systolic function

  • estimation of the pulmonary pressures

Positive Echo for IE

• Vegetations

• Abscess formation

• New partial dehiscence of prosthetic valve

• Pseudoaneurysm

• Leaflet perforation

• Valve aneurysm/fistula

Modified Duke Criteria

Major Findings

• + blood cultures

• Endocardial involvement

• Positive echo findings

• New regurgitation

Minor Findings

• Predisposition (IV drug use, valve disease, etc)

• Vascular phenomena (hemorrhages)

• Fever ≥ 38° C

• Immunological phenome (Osler’s nodes)

Definite

• 2 major

• 1 major + 3 minor

• 5 minor

Typical echocardiographic appearance of Vegetations

• minimum size of a vegetation that is identifiable on transthoracic echocardiography is 3mm

• located on the underside of the valve

  • atrial side of MV/TV

  • ventricular side of AV/PV

  • Where blood flows from 

• hypermobile, echogenic mass

• independent high frequency motion (use m-mode to demonstrate)

• acoustic properties

  • New: similar to myocardium

  • Old/healed: echogenic

Abscess

• Complication of IE

• Extension and penetration of infection to surrounding tissues

• Contains pus

• Non-pulsatile

• Do not communicate with the circulation

• Most common with prosthetic valve & AV IE

• Pus-containing infection of the heart's myocardium or valve tissue

Embolic events

• obstruction of a blood vessel by an infected thrombus/vegetation (septic emboli)

• may cause injury by ischemia & infection

• right side vegetation

  • goes to lungs

• left side vegetation

  • goes to body & brain

• life threatening

• echo can play a key role in predicting embolic events

• increased risk:

  • large mobile vegetation (> 10 mm)

  • vegetation on MV

  • ↑ size of vegetation while antibiotic therapy is given

  • multivalvular infection

  • previous embolic event

  • infection w/specific organisms (Staph, strep, and Candida species)

Valve perforation

• interruption of endocardial tissue continuity that can lead to valve perforating

• hole in the body of the leaflet

• color jet will arise from site other than valve tip

Valve aneurysm

• weakening of valve tissue & loss of elastic components of valve

• leads to a saccular outpouching of valvular tissue

Pseudoaneurysm

• pulsatile

• echo free space

• with flow between the cavity and circulation

Fistula formation

• communication between neighboring cavities via a perforation

• communication confirmed by Doppler (treat as a shunt)