From the Guidelines
Chronic aortic regurgitation can indeed lead to left ventricular wall thickening, also known as left ventricular hypertrophy, as a compensatory mechanism to handle the increased volume overload. This occurs because the incompetent aortic valve allows blood to flow backward into the left ventricle during diastole, resulting in increased end-diastolic volume. The left ventricle adapts to this increased volume by dilating and thickening its walls, a process known as eccentric hypertrophy, which helps maintain normal wall stress according to Laplace's law 1.
Pathophysiological Mechanism
The pathophysiological mechanism behind this adaptation involves the left ventricle handling both the normal forward cardiac output and the regurgitant volume, leading to increased wall stress. To compensate, the ventricle undergoes remodeling, which includes both chamber dilation and wall thickening. This process allows the heart to maintain adequate cardiac output despite the regurgitation. However, if left untreated, this compensatory mechanism can become maladaptive over time, potentially leading to systolic dysfunction.
Clinical Implications
The clinical implications of chronic aortic regurgitation leading to left ventricular hypertrophy are significant. Management typically involves monitoring ventricular dimensions and function with echocardiography. Surgical intervention, such as aortic valve replacement, is recommended when symptoms develop or when ventricular enlargement or dysfunction reaches certain thresholds, even in asymptomatic patients 1. It's crucial to accurately diagnose the severity of aortic regurgitation and to distinguish between primary severe aortic regurgitation and secondary causes of left ventricular dilation and systolic dysfunction.
Key Considerations
Key considerations in the management of patients with chronic aortic regurgitation include:
- Accurate diagnosis of the severity of aortic regurgitation
- Monitoring of ventricular dimensions and function
- Timely surgical intervention when indicated
- Distinguishing between primary and secondary causes of left ventricular dysfunction These considerations are critical for preventing the progression to severe left ventricular dysfunction and for improving outcomes in patients with chronic aortic regurgitation 1.