From the Guidelines
Tricuspid regurgitation (TR) can be diagnosed and assessed using transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE), which provides unique information about the aetiology, severity of disease, RV function and remodelling, RA and annular size, and markers of pulmonary hypertension and left-heart disease 1.
Echocardiogram Findings
The echocardiogram should include:
- Measurements of tricuspid valve annulus diameter
- Assessment of right ventricular size and function
- Estimation of pulmonary artery pressure using the peak velocity of the jet of tricuspid regurgitation, which can be calculated using the simplified Bernoulli equation: PA systolic pressure = tricuspid regurgitation pressure gradient + estimated right atrial pressure 1 Some key points to consider when assessing TR using echocardiography include:
- The use of contrast echocardiography (e.g. agitated saline) to increase the Doppler signal and allow proper measurement of peak tricuspid regurgitation velocity 1
- The estimation of right atrial pressure based on the diameter and respiratory variation of the inferior vena cava, or using a fixed value of 5 or 10 mmHg 1
- The consideration of potential systolic gradients between the RV and PA 1 It is essential to note that the grading of TR may vary across different guidelines, and discrepancies exist about the use of specific criteria for TR grading, such as the identification of cut-off points for colour flow regurgitant jet 1.
From the Research
Echocardiogram Findings for Tricuspid Regurgitation (TR)
Echocardiography is a crucial diagnostic tool for assessing Tricuspid Regurgitation (TR). The following are key echocardiogram findings for TR:
- Tricuspid valve anatomy and morphology
- Tricuspid regurgitation severity, which can be evaluated using 2D and Doppler echocardiography 2
- Right ventricular size and systolic function
- Right atrial size and function
- Estimated pulmonary artery pressure
- Presence of structural abnormalities of the tricuspid valve (TV)
Assessment of TR Severity
The severity of TR can be assessed using various echocardiographic parameters, including:
- Color Doppler jet area and width
- Continuous wave Doppler velocity
- Tricuspid regurgitant volume and fraction
- Right ventricular and right atrial size and function
- Estimated pulmonary artery pressure 3, 4
Echocardiographic Characteristics of Idiopathic TR
Idiopathic TR is a type of TR without an apparent cause. Echocardiographic characteristics of idiopathic TR include:
- Intact TV coaptation
- Adequate estimation of pulmonary artery pressure
- Prominent TV annular dilatation
- High frequency of atrial fibrillation 5
Diagnostic Modalities for TR
Various diagnostic modalities can be used to assess TR, including:
- Two-dimensional transthoracic echocardiography (2D-TTE)
- Three-dimensional transthoracic echocardiography (3D-TTE)
- Transesophageal echocardiography (TEE)
- Multidetector computed tomography (CT)
- Cardiac magnetic resonance imaging (MRI) 6