Acquired Valvular Disease (Stenosis and Regurgitation)

Acquired valvular heart disease is disease of one or more of the heart's four valves that develops after birth, most often from degenerative (age-related) change, rheumatic disease, infection, or as a consequence of disease of the surrounding heart. The two basic mechanical faults are stenosis, in which a valve fails to open fully and obstructs forward flow, and regurgitation, in which a valve fails to close completely and allows backward leakage.

Definition

Acquired valvular heart disease is a structural abnormality of a cardiac valve arising after birth that produces stenosis (obstruction to forward flow), regurgitation (backward leakage), or both, thereby imposing an abnormal pressure or volume load on the adjacent cardiac chambers.

Scope

This topic covers the two fundamental lesions — stenosis and regurgitation — across the aortic, mitral, tricuspid, and pulmonary valves; the loading consequences (pressure load from stenosis, volume load from regurgitation); the principal causes; and how severity is graded by imaging. It is a reference entry on the concepts and classification of valvular disease, not clinical management guidance.

Core questions

• Which valve is affected, and is the dominant lesion stenosis, regurgitation, or mixed?
• Does the lesion impose a pressure load or a volume load, and how do the chambers remodel in response?
• How is severity defined and graded, and what underlying cause is responsible?

Key concepts

• Stenosis (obstruction to forward flow)
• Regurgitation (backward leakage)
• Aortic, mitral, tricuspid, and pulmonary valves
• Pressure load versus volume load
• Transvalvular pressure gradient and valve area
• Primary versus secondary (functional) regurgitation
• Degenerative and rheumatic aetiology

Mechanisms

A stenotic valve resists forward flow, generating a pressure gradient across the valve and a pressure load on the upstream chamber; the classic example is aortic stenosis, which loads the left ventricle and drives concentric hypertrophy. A regurgitant valve allows blood to leak backward during the part of the cycle when it should be closed, imposing a volume load that drives chamber dilatation, as in aortic or mitral regurgitation. Regurgitation may be primary (a lesion of the valve itself) or secondary/functional (the valve leaflets are intrinsically normal but fail to coapt because the supporting ventricle or annulus is dilated). Severity is characterised by integrating the mechanism, the pressure gradient or valve area, the regurgitant volume, and the resulting chamber response, principally with echocardiography (Vahanian, 2022; Otto, 2021).

Clinical relevance

Valvular disease is a frequent cause of heart failure, exertional symptoms, and arrhythmia, and its assessment is a core use of echocardiography. Recognising the difference between stenosis and regurgitation, and between pressure and volume loading, helps in interpreting the cardiology literature and clinical reports. This entry describes concepts and classification and is not a basis for individual diagnostic or treatment decisions.

Epidemiology

Population-based echocardiographic screening found moderate or severe valvular disease in roughly 2.5% of the general population, with prevalence rising steeply with age (Nkomo, 2006). In higher-income settings degenerative aortic stenosis and mitral regurgitation predominate and increase with ageing, whereas rheumatic valve disease remains a major cause in many lower-income regions.

History

Valvular lesions were characterised clinically through auscultation in the eighteenth and nineteenth centuries, and rheumatic fever was long the dominant cause worldwide. The advent of echocardiography and cardiac catheterisation made non-invasive grading of stenosis and regurgitation possible, and as populations aged the epidemiological centre of gravity in high-income countries shifted toward degenerative disease. Contemporary classification and grading are codified in joint society guidelines (Vahanian, 2022; Otto, 2021).

Seminal works

• vahanian-2022
• otto-2021
• nkomo-2006

Frequently asked questions

What is the difference between valve stenosis and valve regurgitation?

Stenosis is a failure of the valve to open fully, obstructing forward flow and imposing a pressure load on the chamber behind it. Regurgitation is a failure of the valve to close fully, allowing backward leakage and imposing a volume load that tends to dilate the chamber.

What is functional (secondary) regurgitation?

It is leakage through a valve whose leaflets are essentially normal, occurring because the supporting ventricle or valve annulus has dilated or remodelled so the leaflets no longer meet properly. It contrasts with primary regurgitation, in which the valve itself is diseased.