Clinical features of mitral stenosis

There are two main presentations of mitral stenosis:

Patients with a normal pulmonary vascular resistance present principally with dyspnoea and pulmonary oedema, a result of increased left atrial pressure. This presentation is more common in younger patients and is exacerbated by situations of increased blood volume, for example, during pregnancy.

Patients with an increased pulmonary vascular resistance present principally with fatigue, mitral facies, a raised JVP, and right ventricular hypertrophy. This presentation is more common in older patients with a low cardiac output and right heart failure. Dyspnoea is less prominent in this group. When the mitral valve is immobile, these patients frequently present with a diagnosis of cor pulmonale as the opening snap and murmur may not be detected.

In general, features of mitral stenosis on examination include:

• small pulse, which may be irregularly irregular
• jugular venous pressure is only raised if there is heart failure
• right ventricular hypertrophy, tapping apex beat
• loud S1, loud P2 if pulmonary hypertension
• opening snap
• mid-diastolic murmur heard at the apex only
• pre-systolic accentuation murmur if no atrial fibrillation

The more severe the stenosis, the larger the left atrium, the worse the dyspnoea, the closer the opening snap is to the second heart sound, and the longer the murmur.