Wednesday, 17 November 2010

MRCP revision battle 52.6: Pulmonary hypertension and cor pulmonale

Definition of pulmonary hypertension

Normal pulmonary artery pressure is 12 to 16 mmHg.

Pulmonary hypertension is defined as pulmonary artery pressure:
  • >25mmHg at rest OR
  • >30mmHg on exercising

Note that technically a Swan-Ganz catheter/cardiac catherisation is needed to diagnose pulmonary hypertension; however, cardiac echo is often used.  Echo reports tend to quote systolic pulmonary artery pressure rather than mean - to convert to mean multiply by 0.61 and add 2.

Cor pulmonale is right heart failure caused by pulmonary hypertension.

Features of pulmonary hypertension

Tends to present with progressive shortness of breath.

On examination look for signs of right heart failure:
  • right ventricular heave
  • raised JVP, a waves
  • loud P2
  • pansystolic murmur - tricuspid regurgitation

Types of pulmonary hypertension

Primary - accounts for <1% pulmonary hypertension
10% of cases are familial and inherited in an autosomal dominant fashion

Secondary  - commonest cause is COPD
Other secondary causes of pulmonary hypertension include:
  • IHD
  • MV disease
  • left to right shunts
  • chronic hypoxia

Treatment of pulmonary hypertension
  • If secondary, treat cause
  • Give diuretics
  • anticoagulate
  • vasodilators:
    • calcium channel blockers
    • IV prostaglandins
    • bosentan = endothelial antagonist
    • sildenafil = PDE-5 inhibitor
  • transplant

5 yr survival is less than 50%

On to a fishy battle...