Tricuspid and Pulmonic Valve Disease

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7 Tricuspid and Pulmonic Valve Disease image

Tricupsid Valve Apparatus Anatomy

image Three leaflets: anterior, posterior, septal

image Chordae

image Papillary muscles

image Annulus

image Right ventricular (RV) myocardium

The three leaflets are supported via chordae. The septal leaflet chordae may insert directly into myocardium without well-formed papillary muscles. Different views are used to image different leaflets:

image RV inflow view

• Anterior leaflet
• Posterior leaflet

image Posterior short-axis view

• Anterior leaflet
• Posterior leaflet
• Septal leaflet

image Apical four-chamber view (4CV)

• Anterior leaflet
• Posterior leaflet

Tricuspid Regurgitation

Scanning Issues

Required parameters to obtain from scanning include the following:

image Valve and RV details to explain the cause of the tricuspid regurgitation (TR)

image TR severity

• Hepatic venous systolic flow pattern
• Jet size, right atrium (RA) size, effective regurgitant orifice (ERO)

image RV size and systolic function, and net forward cardiac index (CI) from the left ventricular outflow tract (LVOT)–velocity time interval (VTI) method

image TR spectral profile

Scanning Notes

image There are problems with color Doppler “quantification” of TR, as there are for color Doppler flow-mapping of any lesions of insufficiency: TR flow-mapping is dependent on gain, angle, position, and jet shape and orientation.

image Retrograde hepatic venous systolic flow reliably establishes that TR is severe.

image Obtain the complete TR profile by appropriate means, and measure in the center of the parabola. The single most common problem with TR spectral recording is not having enough signal to establish the true peak velocity. If the complete profile does not appear to be present, the cursor should be placed off to the side of the profile so that the reviewer is not swayed by the position of the cursor placed by the person recording the study.

image Spectral profiles should be two-thirds the height of the display, and wide enough so that there are two or three per display.

image Use zoom views liberally to identify the valve lesion responsible for TR.

image Proximal isovelocity surface area (PISA) techniques are acceptable for severity assessment, but offer no more than does hepatic venous flow, and therefore are not required.

Reporting Issues

image Describe the suspected cause of the TR (i.e., leaflet, annular or RV disease).

image Describe the severity of the TR.

image Describe the RV function and geometry.

image Note that the right ventricular systolic pressure (RVSP) varies by 25% throughout a given day.

image Ensure that the true peak of the TR jet is used—attempt to avoid under-calling the severity of the RVSP.

image Severe TR

• Hepatic venous systolic flow reversal
• Large PISA
• Large ERO: >40 mm2
• Large vena contracta: >6.5 mm
• Very large jet

image Ancillary findings

• Enlarged RV
• Enlarged RA

image Avoid use of the term “trivial” for TR, as it is normal if the valve is structurally normal.

image RVSP only equates with pulmonary artery (PA) systolic pressure when pulmonic stenosis is absent; therefore, Doppler exclusion of pulmonary stenosis (PS) is essential.

For any given size of tricuspid valve ERO, there is less regurgitant flow than with MR, as the usual RV–RA gradients are less than the usual left ventricular (LV)–left atrial (LA) gradients. Absence of hepatic venous flow reversal is associated with tricuspid valve EROs (<40 mm2) and therefore, in the final analysis, tricuspid valve–ERO generally adds little to hepatic flow profiling.1

Although there is some correlation between TR and RVSP, an important minority of cases of severe pulmonary hypertension lack sufficient TR to be detected by Doppler interrogation.

Causes of Tricuspid Regurgitation

Congenital

image Tricuspid valve dysplasia

• Thickened and shortened leaflets and chordae

image Ebstein’s anomaly

Functional

image “Functional” (i.e., intact leaflet/chordal/papillary components)

• RV annular dilation
• RV body dilation

“Organic”

image Rheumatic

• Characterized by thickening, chordal thickening, commissural thickening, and sometimes by doming
• Thickening and roughness of the leaflet edges impair coaptation.
• Motion is reduced.

image Carcinoid

• Characterized by thickening, chordal thickening, often frank immobility
• Doming is atypical.
• Stenosis usually is concurrent but regurgitation dominates.
• Leaflets typically are “fixed” partially open/partially closed.

image Myxomatous tricuspid valve disease/tricuspid valve prolapse

• May be isolated
• Anterior and septal leaflets usually; therefore, seen on apical 4CV, RV inflow views
• More usually associated with other myxomatous findings (e.g., mitral valve prolapse, aortic root dilation)

image RV papillary muscle rupture: post-infarction, post-trauma, post-biopsy, post–lead extraction

image Pacemakers or implantable defibrillators

• Impinging on a leaflet
• Perforating a leaflet

image Trauma

• Penetrating (e.g., endomyocardial biopsy)
• Blunt force trauma

image Endocarditis

• Septic emboli to the lungs raise the pulmonary artery pressure, which increases the TR.

Ebstein’s Anomaly

image Apical displacement of the septal and or posterior leaflets

image Displacement > 8 mm/m2

image “Atrialization” of the right ventricle

image “Tethering” of the anterior leaflet

image Smaller functional right ventricle

image The amount of TR is usually worst at birth as the PVR is highest

image Right-to-left shunting may occur:

• Through a patent foramen ovale, as tricupsid insufficiency and right ventricular dysfunction occur.
• Through an anterior septal defect

Estimation of Right Ventricular Systolic Pressure

The RV–RA gradient is calculated, and the right atrial pressure (RAP) is estimated: therefore, the RVSP is both calculated and estimated. Some TR is recordable in >95% of cases.

Potential problems in estimating the RVSP include the following:

image No TR from which to determine RV–RA gradient

image Insufficient TR from which to determine maximum RV–RA gradient

image Incomplete TR profile (missing peak)

image The RAP estimate is only that.

The TR gradient method to estimate RVSP is a clinical workhorse, not a racehorse. The overall correlation is very good, but there is a tendency to overestimate lower RVSP and to underestimate high RVSP.

image Over-estimation of low RVSP

• Due to estimation of RAP as, for example, 10 mm Hg, which is higher than normal physiologic RAP (–2–8 mm Hg)

image Underestimation of high RVSP

• Due to estimation of RAP as, for example, 10 mm Hg, which is lower than may occur in several disease states (RV infarction, restrictive cardiomyopathy, constrictive pericarditis, terminal cor pulmonale) where the RVSP may be 20 to 35 mm Hg

image Inability to record the full TR profile due to inadequate signal

• As the echocardiography:catheterization relation demonstrates this tendency for echocardiography to overestimate RVSP at lower pressures, and to underestimate it at higher pressures when a “fixed” RAP of 10 mm Hg is added, use of 5, 10, and 15 mm Hg seems reasonable, at the operator’s discretion. The presence of extremely high RAPs will systematically lead to underestimation of the RVSP.

The correlation of RV:RA gradient is excellent (r = 0.95; SEE = 7 mm Hg)2 (r = 0.96; SEE = 7 mm Hg),3 but the correlation of jugular venous pressure estimate to catheter RAP is less good (r = 0.80; SEE = 2.3 mm Hg). Clearly, clinical estimate of jugular venous pressure overestimates lower RAPs (<8 cm) and underestimates higher RAPs—sometimes by 40% when the true RAP is 20 mm Hg.

More patients with an elevated RVSP have analyzable TR spectral profiles than do patients (half) with normal RVSP.3 However, an important minority subset of patients with severely elevated RVSP (approximately 20–25% of cases of primary pulmonary hypertension) may not have associated TR to yield an analyzable (complete) TR spectral profile. Overall, the correlation of echocardiographic RVSP to catheter RVSP is quite good (r = 0.93; SEE = 8 mm), but remains influenced by the vagaries of estimating jugular venous pressure and RAP.2

Indications for the management and intervention in tricuspid regurgitation are listed in Boxes 7-1 and 7-2.

Tricuspid Stenosis

Scanning Issues

Required parameters to obtain from scanning include the following:

image Valve morphology and motion (doming)

image Mean gradient, spectral profile characteristics

• Measure three spectral profiles at a high sweep speed (100 mm/sec) if in sinus rhythm and five spectral profiles if in atrial fibrillation.
• Do not measure at inspiration; measure at end expiration.

image RA size

As the tricuspid valve has three commissures, extensive disease must be present (at least two commissures) to cause stenosis. Echocardiographic features of tricuspid stenosis (TS) include the following:

image Evidence of flow convergence across the tricuspid valve

image Doming motion or frozen leaflets

image Mean gradient ≥ 5 mm Hg

image Marked prolongation of the pressure half time (PHT), and elevation of the end-diastolic velocity (PHT ≥ 190 msec)

image Ancillary findings: dilated RA and inferior vena cava

Causes of Tricuspid Stenosis

image Congenital

• Tricuspid atresia

image Acquired

• Rheumatic: Anterior leaflet doming is usual/invariable in tricuspid stenosis cases
• Carcinoid (discussed earlier in chapter)
• Tight annuloplasty ring
• Large vegatations
• Pacemaker-induced lesions

Tricuspid Atresia

image There is no continuity between the right atrial and right ventricular cavities. A thick barrier/band separates the two.

image The right ventricle, without blood volume within it, is hypoplastic.

image An anterior septal defect, with or without a ventricular septal defect, is present.

image Transposition of the great arteries may be present.

Concerns

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