Arteriovenous fistula

• Facts:
  May be congenital, but usually occurs after trauma
  
  Shunting of large amounts of blood through fistula increases cardiac preload and cardiac output ( high output cardiac failure )
  
• History / PE:
  Widened pulse pressure
  Strong peripheral arterial pulsation (brisk carotid upstroke)
  Tachycardia
  Flushed extremities
  
• Diagnosis:
  Left ventricular hypertrophy (displaced PMI)
  
• Complications:
  Patients develop heart failure despite maintaining a normal or high cardiac output because the circulation is unable to meet the oxygen demand of the peripheral tissues
• Differential Diagnosis:
  Thyrotoxicosis
  Paget's disease
  Anemia
  Thiamine deficiency