Valvular vitiums and their consequences

1. Definitions

• Stenosis — failure of a valve to fully open (narrowing) → obstruction to forward flow.
• Insufficiency / regurgitation — failure of a valve to fully close → backflow.
• May be pure or mixed; collectively called a vitium. Produces abnormal heart sounds (murmurs).
• Secondary changes: chamber hypertrophy/dilation, endocardial thickening (jet-stream injury).

2. General principles

Outcome depends on the valve involved, degree of impairment, speed of development, and quality of compensation. ~2/3 of valve diseases are acquired stenoses of the aortic and mitral valves. The mitral valve is most often affected.

3. Causes of valvular disease

Cause	Lesion
Rheumatic fever	Verrucae → mitral stenosis (“fish-mouth”)
Infective endocarditis	Bulky, destructive vegetations
Non-infective (NBTE / Libman-Sacks)	Sterile fibrin / SLE fibrinoid vegetations
Carcinoid heart disease	Right-sided plaque-like fibrous thickening
Myxomatous mitral valve	Floppy prolapsing leaflets
Calcific aortic stenosis	Calcified cusp masses

4. Carcinoid heart disease

• Cardiac manifestation of carcinoid syndrome: intestinal carcinoid tumor secretes vasoactive amines (serotonin, bradykinin, kallikrein).
• Normally inactivated by liver/lung monoamine oxidase; with liver metastases the amines reach the right heart → plaque-like fibrous thickening.
• Left heart is spared (lungs inactivate the amines first).
• → Tricuspid insufficiency + pulmonary stenosis → right-sided HF.

5. Hemodynamic consequences

• Stenosis → pressure overload upstream → concentric hypertrophy (e.g., aortic stenosis → LV; mitral stenosis → LA → pulmonary congestion).
• Insufficiency → volume overload → eccentric hypertrophy + dilation.
• Long-term: heart failure, arrhythmia, mural thrombi/embolism, predisposition to infective endocarditis.

💡 High-yield: Stenosis = can’t open → pressure overload → concentric hypertrophy; insufficiency = can’t close → volume overload → eccentric hypertrophy + dilation. Causes: RF, IE, NBTE/Libman-Sacks, carcinoid, myxomatous MV, calcific AS. Carcinoid → right-sided (tricuspid insufficiency + pulmonary stenosis); left heart spared.