From the Guidelines
The workup of a patient with a mildly dilated right ventricle (RV) should begin with a comprehensive echocardiography, as it provides essential information on anatomy, function, and haemodynamics, and is the 'first step' imaging technique, as recommended by the European Association of Cardiovascular Imaging 1.
Initial Evaluation
The initial evaluation should include a thorough history and physical examination to identify potential causes of RV dilation. Key elements include assessing for symptoms of dyspnea, fatigue, syncope, chest pain, and palpitations. The physical exam should focus on signs of right heart failure such as elevated jugular venous pressure, peripheral edema, and a right-sided S3 or S4 gallop.
Diagnostic Testing
Initial diagnostic testing should include:
- An electrocardiogram to evaluate for right ventricular hypertrophy, right axis deviation, or arrhythmias
- A chest X-ray to assess for cardiomegaly or pulmonary abnormalities
- Echocardiography to confirm RV dilation, assess RV function, estimate pulmonary artery pressures, and evaluate for structural abnormalities Additional testing may include:
- Pulmonary function tests to rule out pulmonary causes
- Cardiac MRI for detailed RV assessment, as it is the gold standard for measuring LV- and RV volumes, and ejection fraction, and provides tissue characterization and may suggest the cause of ventricular dysfunction 1
- CT pulmonary angiography if pulmonary embolism is suspected
- Right heart catheterization if pulmonary hypertension is a concern
Laboratory Tests
Laboratory tests should include:
- BNP or NT-proBNP
- Troponin
- D-dimer if PE is suspected
- Tests for underlying conditions like thyroid dysfunction or connective tissue disorders
Goal of Evaluation
The goal is to identify the underlying cause of RV dilation, which could include pressure overload (pulmonary hypertension), volume overload (atrial septal defect), or intrinsic myocardial disease (arrhythmogenic right ventricular cardiomyopathy), as treatment will be directed at the specific etiology rather than the RV dilation itself. It is also important to assess RV function using parameters such as tricuspid annular plane systolic excursion (TAPSE) and systolic myocardial velocities, although these may be less accurate in patients with severe tricuspid regurgitation, and less load-dependent parameters such as 2D longitudinal strain and strain rate may be more useful in this setting 1.
From the Research
Assessment of Right Ventricular Function
To work up a patient with a mildly dilated right ventricle (RV), several diagnostic approaches can be considered:
- Echocardiography: Transthoracic right heart echocardiography can be used to assess RV function, as discussed in 2. Measurements such as tricuspid annular plane systolic excursion (TAPSE), RV fractional area change (FAC%), and Doppler tissue imaging-derived peak systolic velocity (S') can provide valuable information on RV systolic function.
- Cardiac Magnetic Resonance Imaging (MRI): MRI is a reliable technique for assessing RV morphology, volumes, and function, as noted in 3. It can provide a comprehensive approach to evaluating the RV, including assessment of cardiac morphology, myocardial tissue characteristics, flow patterns, and great vessel anatomy.
- Right Ventricular Strain Measurement: The right ventricle strain measured by speckle tracking (RVS) is an echocardiographic parameter that can be used to assess RV function, as compared to cardiac MRI in 4.
Clinical Scenarios and Prognostic Implications
RV dysfunction can be a significant prognostic factor in various cardiovascular diseases, including:
- Dilated Cardiomyopathy: RV involvement is common in dilated cardiomyopathy (DCM), and the presence of right ventricular dysfunction (RVD) is a major negative prognostic determinant, as discussed in 5.
- Tetralogy of Fallot: Pulmonary valve replacement may be beneficial for refractory arrhythmias in adult patients with a severely dilated RV after repair of tetralogy of Fallot, as shown in 6.
- Critical Illness: RV dysfunction can occur in critically ill patients, particularly those with conditions such as acute respiratory distress syndrome, pulmonary embolism, RV ischemia, and pulmonary hypertension, as noted in 2.