From the Guidelines
Right ventricular enlargement is primarily caused by conditions that increase the workload on the right ventricle, such as pulmonary hypertension, right ventricular volume overload, and right ventricular infarction, as highlighted in a scientific statement from the American Heart Association 1. The etiology of right ventricular enlargement can be multifactorial, involving various cardiac and non-cardiac conditions. Key causes include:
- Primary cardiomyopathies with right ventricular involvement
- RV ischemia and infarction
- Volume loading caused by cardiac lesions associated with congenital heart disease and valvular pathologies
- Pressure loading resulting from pulmonic stenosis or pulmonary hypertension from a variety of causes, including left-sided heart disease, as noted in the evaluation and management of right-sided heart failure 1. Progressive RV dysfunction in these disease states is associated with increased morbidity and mortality, emphasizing the importance of early diagnosis and management.
The diagnosis of right ventricular enlargement typically involves imaging techniques such as echocardiography, cardiac MRI, or CT scanning to assess right ventricular size and function. Treatment strategies focus on addressing the underlying cause of the enlargement, rather than the enlargement itself, and may include vasodilators for pulmonary hypertension, diuretics for volume overload, or surgical correction of congenital defects. The management approach should prioritize reducing the workload on the right ventricle and preventing further remodeling and dysfunction 1.
From the Research
Etiology of Right Ventricular Enlargement
The etiology of right ventricular enlargement is a complex phenomenon that can be caused by various factors. Some of the key factors include:
- Pulmonary hypertension: This is a major cause of right ventricular enlargement, as it increases the afterload on the right ventricle, leading to hypertrophy and dilation 2, 3, 4.
- Congenital heart disease: Certain congenital heart diseases, such as those that affect the tricuspid valve or the pulmonary valve, can lead to right ventricular enlargement 5.
- Hypertrophic cardiomyopathy: This condition can also lead to right ventricular enlargement, particularly if there is significant septal hypertrophy or outflow tract obstruction 6.
- Tricuspid regurgitation: This condition can lead to right ventricular enlargement due to the increased volume load on the right ventricle 5.
Pathophysiology of Right Ventricular Enlargement
The pathophysiology of right ventricular enlargement involves a complex interplay between the right ventricle and the pulmonary circulation. Some of the key mechanisms include:
- Increased afterload: This leads to hypertrophy and dilation of the right ventricle, which can eventually lead to right heart failure 2, 3, 4.
- Myocardial fibrosis: This can lead to stiffening of the right ventricle, making it less compliant and more prone to failure 2, 3.
- Capillary rarefaction: This can lead to decreased oxygen delivery to the right ventricular myocardium, contributing to right ventricular failure 2.
- Disturbed metabolism: This can lead to changes in the energy metabolism of the right ventricle, contributing to right ventricular failure 2.
Clinical Implications of Right Ventricular Enlargement
Right ventricular enlargement has significant clinical implications, including:
- Increased mortality: Right ventricular enlargement is associated with increased mortality, particularly in patients with pulmonary hypertension or hypertrophic cardiomyopathy 6, 2, 3.
- Decreased functional status: Right ventricular enlargement can lead to decreased functional status, particularly in patients with pulmonary hypertension or congenital heart disease 3, 5.
- Increased risk of right heart failure: Right ventricular enlargement is a significant risk factor for right heart failure, particularly in patients with pulmonary hypertension or hypertrophic cardiomyopathy 6, 2, 3.