Atlas of Transesophageal Echocardiography, 2nd Edition (2007)

Chapter 4. Tricuspid and Pulmonary Valves

The tricuspid valve is well imaged by transesophageal echocardiography (TEE). The septal and anterior leaflets are seen in the transverse plane (four-chamber and right ventricular inflow views), and the anterior and posterior leaflets are imaged in the longitudinal plane. Tricuspid stenosis is unusual in the absence of mitral stenosis. Even small pressure gradients across a tricuspid valve may indicate significant stenosis.

Tricuspid regurgitation is far more common than stenosis. The most common cause of moderate or severe tricuspid regurgitation is right heart dilatation. Mild tricuspid regurgitation is seen commonly in healthy individuals. The absolute jet area is used to semiquantitate the severity of tricuspid regurgitation; therefore, it is important to image the tricuspid valve in multiple planes to find the maximum jet area. No angiographically validated gold standard exists for quantifying tricuspid regurgitation. In the absence of such a standard, the criteria used to quantify mitral regurgitation are frequently used. Since the right atrium is not always completely visualized on TEE in the same view as the maximum regurgitant jet area, absolute areas have been used. Mild tricuspid regurgitation is considered to be present when the maximum jet area is 4 cm2, moderate when the jet area is 4 to 8 cm2, and severe when the jet is 8 cm2. Proximal flow acceleration and a large vena contracta area are also important markers of significant regurgitation. Additionally, the right atrium generally enlarges in the setting of significant chronic tricuspid regurgitation and this is also a useful, if qualitative, sign of significant tricuspid regurgitation.

The pulmonary artery pressure can be estimated in the absence of pulmonic stenosis. As is done with transthoracic echocardiography, the systolic pressure in the right ventricle (and therefore, approximately in the pulmonary artery), is estimated as

PAsys = 4 Vmax2 + RAP

where PAsys is the pulmonary artery systolic pressure, Vmax is the maximum velocity of the regurgitant tricuspid jet, and RAP is an estimate of the right atrial pressure. Care must be taken to align the beam with the maximum tricuspid regurgitation jet, which may be more difficult on TEE than on transthoracic echocardiography with the views available. If the jet is not aligned, the pressure will be underestimated. Estimation of the pulmonary artery systolic pressure is helpful in the assessment of the reason for tricuspid regurgitation.

Tricuspid prolapse most often accompanies mitral prolapse, but can also occur in its absence. The most specific pattern of prolapse occurs when one or more of the redundant leaflets show a distinct bulge into the right atrium during systole. Prolapse may result in the entire spectrum of regurgitation, from mild to severe, and the regurgitant jet may be eccentric. In some patients, myxomatous degeneration may result in the prominent thickening of a prolapsing tricuspid valve.

Pulmonary stenotic lesions are primarily associated with congenital heart disease. However, mild pulmonary regurgitation is often noted in healthy individuals, and therefore may be considered “normal” or “physiologic.” More severe degrees of pulmonary regurgitation result from pulmonary hypertension or right heart/pulmonary artery dilatation from other causes. In the absence of an angiographic “gold standard,” the criteria used for the assessment of the severity of aortic regurgitation have also been applied for grading the severity of pulmonary regurgitation. A ratio of the jet width at its origin from the pulmonary valve to the right ventricular outflow tract diameter, taken at the same point, of 38% or less is considered mild or moderate pulmonary regurgitation, 39% to 74% is moderately severe, and 75% or more indicates severe regurgitation. The distance the pulmonary regurgitation jet travels in the right ventricular outflow tract has also been found useful in assessing its severity, especially in the presence of infundibular stenosis, which narrows the outflow tract. In our experience, a regurgitation jet reaching within 1 cm of the tricuspid valve always denotes severe pulmonary regurgitation. It is particularly important not to rely on the presence of turbulent flow to identify tricuspid or pulmonary regurgitation since the regurgitant flow signals may be laminar and totally devoid of aliasing and variance when the right atrial or pulmonary artery diastolic pressures are high. In some such instances, torrential pulmonary and tricuspid regurgitation have been completely missed. The pulmonary valve may show redundancy, thickening, and prolapse resulting from myxomatous degeneration, and the resulting regurgitation may be eccentric. Pulmonary valve prolapse is often associated with prolapse of other valves. Both tricuspid and pulmonary valves may show evidence of infection, especially in drug addicts.

FIGURE 4.1. Tricuspid regurgitationA. A small jet of mild tricuspid regurgitation (TR). This is often seen in normal individuals. B. The regurgitant jet (arrow) is larger and represents moderate TR. Note the presence of flow acceleration on the ventricular aspect of the tricuspid valve (TV). C–G. Show much larger jets, indicative of severe TR. Prominent flow acceleration is present in (C). D. A relatively small zone of flow acceleration (arrow) is seen, even though the patient has torrential TR, almost completely filling the massively dilated right atrium (RA). Marked turbulence of the TR jet is seen in (E) and in the color M-mode (arrows, F). G. Transgastric view demonstrates severe TR. LA, left atrium; LV, left ventricle; RV, right ventricle. (D reproduced with permission from 

Rosenthal SM, Nanda NC. Assessment of valvular regurgitation by transesophageal echocardiography. J Invasive Cardiol 1992;4:366–372.

)

FIGURE 4.2. Tricuspid valve prolapseA. Prolapse of both anterior (arrow) and septal leaflets of the tricuspid valve (TV). B. Another patient with tricuspid valve prolapse. A medially located eccentric tricuspid regurgitation (TR) jet originating from the septal leaflet and extending into the inferior vena cava (IVC) and coronary sinus (CS) is seen. C.Four-chamber view of another patient with TV prolapse (arrow). Note that the mitral valve (MV) is thickened but does not prolapse. D–H. Another patient with prolapse (arrow) of the septal leaflet of the TV with an eccentric TR jet directed along the right atrium (RA) free wall. Note the presence of flow acceleration on the ventricular side of the TV. Examination in the longitudinal plane shows two jets of TR in (G) and all three leaflets of the TV in (H)A, anterior leaflet; P, posterior leaflet; S, septal leaflet. I–O. Another patient with TV prolapse. Marked prolapse of the TV with thickening (arrowheads) consistent with myxomatous degeneration is noted. In some views (J, M, N, and O) the marked thickening and redundancy produce the appearance of a mass. AO, aorta; ATV, anterior tricuspid leaflet; LA, left atrium; LV, left ventricle; RV, right ventricle; SVC, superior vena cava; VS, ventricular septum. (I–O are courtesy of Dr. Alan Schwadron, Montgomery, AL.)

FIGURE 4.3. Tricuspid regurgitationA. Two jets of tricuspid regurgitation (TR) are noted extending into the right atrium (RA) adjacent to the coronary sinus. B. Another patient with a TR jet impacting the atrial septum (AS). C–E. A patient with both TR (arrows in C–E) and mitral regurgitation (MR) (upper arrow in C) impacting the atrial septum, mimicking atrial septal defect. Careful angulation of the multiplane probe helps to exclude the presence of an AS defect. AO, aorta; CS, coronary sinus; LA, left atrium; LAA, left atrial appendage; RAA, right atrial appendage; SVC, superior vena cava.

FIGURE 4.4. Tricuspid regurgitationA. The anterior leaflet (arrow) and the septal leaflet (arrowhead), which demonstrate a localized prolapse. B. Note noncoaptation (arrow) of the anterior and septal leaflets of the tricuspid valve (TV) in this patient with severe tricuspid regurgitation (TR) and massively dilated right atrium (RA). C,D. Prominent flow acceleration and severe TR (arrows). The arrowhead in (D) shows associated mild mitral regurgitation (MR). E. TR appears less severe, but the presence of large flow acceleration (arrow) suggests that the regurgitation is indeed severe. F. The patient shown in (E) underwent porcine replacement of the TV (arrows). G. Another patient with an eccentric TR jet (arrows), which initially moves along the septal leaflet and is then in contact with the atrial septum (AS). AO, aorta; LA, left atrium; LV, left ventricle; LVO, left ventricular outflow tract; RA, right atrium; RV, right ventricle.

FIGURE 4.5. Tricuspid valve endocarditisA,B. Multiplane examination shows a large vegetation (arrow) attached to the anterior (A) tricuspid leaflet. The posterior (P) tricuspid leaflet is not involved. AO, aorta; LA, left atrium; RA, right atrium; RV, right ventricle. (Reproduced with permission from 

Maxted W, Nanda NC, Kim KS, et al. Transesophageal echocardiographic identification and validation of individual tricuspid valve leaflets. Echocardiography 1994;11:585–590.

)

FIGURE 4.6. Pulmonic regurgitationA. A very small jet of mild pulmonary regurgitation (PR). B. The PR jet occupies almost the entire extent of the proximal right ventricular outflow tract (RVO), indicating severe regurgitation. This patient previously had patch repair of a ventricular septal (VS) defect. AO, aorta; LA, left atrium; LV, left ventricle;PA, pulmonary artery; RV, right ventricle.

FIGURE 4.7. Pulmonary valve prolapseA,B. Prolapse of the left and anterior cusps of the pulmonary valve (PV). C,D. All three leaflets of the PV are seen in the short axis. A, anterior; L, left; P, posterior. E–H. Associated eccentric jets of pulmonary regurgitation (PR) (arrowheads). AO, aorta; LA, left atrium; LV, left ventricle; PA, pulmonary artery;RV, right ventricle; RVO, right ventricular outflow tract.

FIGURE 4.8. Transesophageal echocardiographic detection of Lambl's excrescences on the pulmonary valve (PV). The arrow points to a large excrescence involving the PV. AO, aorta; LA, left atrium. (Reproduced with permission from 

Szilard Voros, Navin C, Nanda Abhash C. Thakur, Virenjan K. Narayan, Aditya K. Samal: Lambl's Excrescences Involving the Pulmonary Valve Detected by Transesophageal Echocardiography. Echocardiography 1999;16:35–39.

)

 

Suggested Readings

Cook JW. Accurate adjustment of de Vega tricuspid annuloplasty using transesophageal echocardiography. Ann Thorac Surg 1994;58:570–572.

Guarneri E, Tunick PA, Kennedy JT, et al. Horizontal plane transesophageal echocardiography may be false negative for large tricuspid vegetations. Echocardiography 1994;11:35–37.

Hancock HL, D'Cruz IA. Doppler-phonocardiographic findings in tricuspid valve prolapse. Echocardiography 1993;10:265–267.

Hutchison SJ, Rosin BL, Curry S, et al. Transesophageal echocardiographic assessment of lesions of the right ventricular outflow tract and pulmonic valve. Echocardiography 1996;13:21–34.

Kai H, Koyanagi S, Hirooka Y, et al. Right-to-left shunt across atrial septal defect related to tricuspid regurgitation: assessment by transesophageal Doppler echocardiography. Am Heart J 1994;127:578–584.

Karatasakis G, Karamintziou R, Taylor KM. Transthoracic and transesophageal echocardiographic diagnosis of a De Vega tricuspid annuloplasty rupture. J Am Soc Echocardiogr 1994;7:321–323.

Maxted W, Nanda NC, Kim KS, et al. Transesophageal echocardiographic identification and validation of individual tricuspid valve leaflets. Echocardiography 1994;11:585–590.

Meijburg HWJ, Bisser CA. Pulmonary venous flow as assessed by Doppler echocardiography: potential clinical applications. Echocardiography 1995;12:425–440.

Rollefson WA, Winslow TM, Adams CW, et al. Traumatic dehiscence of a tricuspid annuloplasty ring: diagnosis by transesophageal echocardiography. Am Heart J 1994;127:708–710.

Rosenthal SM, Nanda NC. Assessment of valvular regurgitation by transesophageal echocardiography. J Invasive Cardiol 1992;4:366–372.

Tariq M, Smego RA Jr, Soofi A, et al. Pulmonic valve endocarditis. South Med J 2003;96:621–623.

Van TB, Halldorsson A, Baucum RW, et al. Retrieval of a distal right pulmonary artery vegetative embolus under transesophageal echocardiographic guidance. Echocardiography 1993;10:489–495.

Voros S, Nanda NC, Thakur AC, et al. Lambl's excrescences involving the pulmonary valve detected by transesophageal echocardiography. Echocardiography 1999;16:35–39.