Differential diagnosis

The differential diagnosis for mitral stenosis includes:

• atrial fibrillation without mitral stenosis
  
  
• primary pulmonary hypertension
  
  
• a left to right shunt:
  • atrial septal defect - the dilated right ventricle may reach the axilla causing apical short ventricular filling murmurs because of high flow through the tricuspid valve
  • ventricular septal defect, patent ductus arteriosus - these conditions may cause mitral flow murmurs
    
    
• Austin Flint murmur:
  • the murmur of mitral stenosis may be indistinguishable from the Austin Flint murmur of pure aortic regurgitation
  • mitral stenosis usually has a loud first heart sound which is absent in aortic regurgitation
  • a definite diagnosis may require echocardiography
    
    
• left atrial myxoma:
  • the tumour may lie in the mitral orifice and so is sometimes misdiagnosed as mitral stenosis
  • frequently there are systemic emboli
  • diagnosis is made via histology of an embolus or by echocardiography
    
    
• Carey-Coombs murmur:
  • this is a variable, high-pitched mid-diastolic murmur heard during the acute valvulitic phase of rheumatic fever