From the Guidelines
Right ventricular dilation is a critical condition that necessitates immediate evaluation and treatment, as it is associated with increased morbidity and mortality if left untreated. The right ventricle dilates in response to pressure or volume overload, which can be caused by various factors such as pulmonary hypertension, pulmonary embolism, right-sided valvular disease, congenital heart defects, or left heart failure 1.
Causes and Pathophysiology
The right ventricle has a unique geometry and function compared to the left ventricle, with a lower peak systolic pressure and a higher steady-state volume 1. The right ventricle is highly sensitive to changes in afterload, and minor increases in afterload can cause large decreases in stroke volume. The law of LaPlace dictates that wall stress is directly proportional to intracavitary pressure and internal ventricular diameter, and inversely related to ventricular wall thickness 1.
Treatment and Management
Treatment of right ventricular dilation focuses on addressing the underlying cause while supporting right ventricular function. For pulmonary hypertension, medications like sildenafil (20-80mg three times daily), bosentan (62.5-125mg twice daily), or prostacyclin analogs may be prescribed 1. Diuretics like furosemide (20-80mg daily) can help manage fluid overload, while inotropes such as dobutamine (2.5-10 μg/kg/min) or milrinone may support right ventricular function in acute settings 1. Oxygen therapy maintains adequate saturation, and in severe cases, mechanical circulatory support may be necessary. Regular echocardiographic monitoring is essential to track progression and treatment response.
Key Considerations
- Diuretics can be useful for patients with severe tricuspid regurgitation and signs of right-sided heart failure 1
- RV afterload is most appropriately defined as the RV wall stress during systolic ejection estimated by the summation of the resistive and pulsatile components of blood flow 1
- Optimal ventricular efficiency is achieved if end-systolic elastance is matched by vascular load, defined by arterial elastance 1
- The pressure-overloaded RV is at increased risk for developing ischemia as a result of decreased perfusion pressure in the setting of increased RV intramural pressure and decreased systemic arterial pressure 1
From the Research
Significance of Right Ventricular Dilation
- Right ventricular (RV) dilation is a condition where the right ventricle of the heart becomes enlarged, which can be caused by various factors such as pulmonary hypertension, RV volume overload, RV pressure overload, and RV myocardial disease 2.
- RV dilation can lead to impaired left ventricular systolic performance, as the increased volume of the right ventricle can reduce the preload and compliance of the left ventricle 3.
- The condition can also be associated with pulmonary embolism, and bedside echocardiography performed by emergency physicians can aid in the diagnosis of pulmonary embolism by identifying RV dilation and dysfunction 4.
Treatment of Right Ventricular Dilation
- Sildenafil has been used to treat pulmonary hypertension associated with RV dilation, and has been shown to improve outcomes in patients with persistent pulmonary hypertension of the newborn 5.
- However, in patients with heart failure with preserved ejection fraction (HFpEF) and RV dysfunction, sildenafil did not improve RV function, exercise capacity, or ventilatory efficiency 6.
- The treatment of RV dilation depends on the underlying cause, and may involve addressing the underlying condition, such as pulmonary hypertension or RV myocardial disease, as well as managing symptoms and preventing complications.
Diagnostic Approaches
- Transthoracic echocardiography (TTE) is often the initial means of detecting RV dilation, and can be used to assess RV volume overload, RV pressure overload, and RV myocardial disease 2.
- Three-dimensional echocardiography may be useful in determining the intervention timing in patients with congenital heart disease and RV volume overload 2.
- Bedside echocardiography performed by emergency physicians can aid in the diagnosis of pulmonary embolism by identifying RV dilation and dysfunction 4.