What is the commonest cause of mitral stenosis?
Rheumatic heart disease.
What is the mechanism of tapping apex beat?
It is due to an accentuated first heart sound.
What does the opening snap indicate?
The opening snap is caused by the opening of the stenosed mitral valve and indicates that the leaflets are pliable. The opening snap is usually accompanied by a loud first heart sound. It is absent when the valve is diffusely calcified. When only the tips of the leaflets are calcified, the opening snap persists.
What is the mechanism of a loud first heart sound?
The loud first heart sound occurs when the valve leaflets are mobile. The valve is open during diastole and is suddenly slammed shut by ventficular contraction in systole.
What is the mechanism of presystolic accentuation of the murmur?
In sinus rhythm it is due to the atrial systole which increases flow across the stenotic valve from the left atrium to the left ventricle; this causes accentuation of the loudness of the murmur. This may also be seen in atrial fibrillation and is explained by the turbulent flow caused by the mitral valve starting to close with the onset of ventricular systole. This occurs before the first heart sound and gives the impression of falling in late diastole; it is, however, due to the start of ventricular systole.
What are the complications?
· Left atrial enlargement and atrial fibrillation.
· Systemic embolization, usually of the cerebral hemispheres.
· Pulmonary hypertension.
· Tricuspid regurgitation.
· Right heart failure.
What are some rarer causes of mitral stenosis?
· Calcification of mitral annulus and leatlets.
· Rheumatoid arthritis.
· Systemic lupus erythematosus.
· Malignant carcinoid.
· Congenital stenosis.
Which conditions simulate mitral stenosis?
· Left atrial myxoma.
· Ball valve thrombus in the left atrium.
· Cor triatriatum
Have you heard of Ortner's syndrome?
It refers to the hoarseness of voice caused by left vocal cord paralysis associated with enlarged left atrium in mitral stenosis.
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