Pulmonary hypertension & cor pulmonale

Question 1

The lungs are normally a high flow, low pressure system. What is the normal mean pulmonary arterial pressure ?

Answer 1

mPAP = 12-20

Question 2

Define what pulmonary HTN is

Answer 2

This is a mPAP ≥ 25mmHg. It is caused by a number of different diseases & is characterised by a progressive increase of pulmonary vascular resistance leading to R-ventricular failure & premature death

Question 3

How is mPAP measured ?

Answer 3

With a R heart catheter (invasive)

Question 4

Measuring what may be used to also indicate pulmonary HTN?

Answer 4

• Systolic pulmonary arterial pressure using Doppler ECHO
• Possible pulmonary HTN is indicated if systolic pulmonary arterial pressure is > 40 (but this varies for age/weight)

Question 5

What are the different causes of pulmonary hypertension ?

Answer 5

• Left heart disease; LVSD - ischaemic, Mitral reguritation or MS, cardiomyopathy, viral
• Primary pulmonary HTN (PAH) - idiopathic i.e. no known cause
• Lung disease e.g. COPD, OSA, pulmonary fibrosis, severe chronic asthma
• Multiple PE’s causing chronic thromboembolic pulmonary hypertension (CTEPH)
• Vasculitis e.g. SLE, polyarteritis nodosa (PAN), systemic sclerosis
• Drugs e.g. appetite suppressants (fenfluramine)
• HIV
• Cardiac left to right shunts e.g. ASD, VSD
• Neuromuscular disease e.g. Myasthenia gravis, MND, poliomyelitis
• Thoracic cage abnormality - kyphoscoliosis, thoacoplasty
• Sickle cell disease

Question 6

Define what cor pulmonale is

Answer 6

This is R-heart failure secondary to chronic pulmonary HTN complicating lung disease

Question 7

What are the clinical features of pulmonary HTN & right heart failure (cor pulmonale)?

Answer 7

Signs:

• Central cyanosis
• Raised JVP with prominent a & v waves
• Loud P2
• Pansystolic mumur (tricuspid regurgitation)
• R-ventricular heave @ left parasternal edge
• Hepatomegaly +/- liver pulsatility
• Peripheral pitting oedema

Symptoms:

• Progressive SOB (particularly at rest)
• Weakness/fatigue
• External syncope & dizziness

Question 8

What Investigations may be done in someone with suspected pulmonary hypertension ?

Answer 8

• ECG
• CXR
• SaO2 & ABG’s
• PFT’s & DLCO
• Echo
• Cardiac catheterisation
• D-dimer
• V/Q scan or CTPA
• Cardiac MRI
• Auto-antibodies if vasculitis suspected

Question 9

What is the treatment of primary pulmonary HTN (idiopathic) specifically ?

Answer 9

Exclude other secondary causes

Give prophylactic anticoagulation (warfarin)

Give O2 if hypoxic

Give pulmonary vasodilators options include:

• Ca2+ channel blockers (oral nifedipine ,diltiazem)
• Endothelin antagonist (Oral Bosentan,Macitentan)
• PDE5-inhibitor (Oral Sildenafil/Tadalafil)
• Prostanoids (IV Epoprostenol or Inhaled Iloprost)
• Soluble Guanylate Cyclase stimulator (Riociguat)

May need lung transplant

Question 10

What is the specific treatment of CTEPH?

Answer 10

Riociguat which is a pulmonary arterial vasodilator or pulmonary endartectomy which is curative

Question 11

What is the general management of the other causes of pulmonary HTN?

Answer 11

Treat the underlying cause

Question 12

What is the management of cor pulmonale ?

Answer 12

• Treat the underlying the cause
• Treat resp failure - oxygen
• Treat cardiac failure
• Consider venesection if haematocrit
• Consider heart-lung transplantation