Pulmonary HTN

Question 1

What are the 5 classes of pulmonary HTN?

Answer 1

I - pulmonary arterial HTN (idiopathic or heritable)

II - secondary to L heart disease

III - primary lung problem (COPD, fibrosis, hypoxic vasoconstriction from sleep apnea or high alt)

IV - chronic thromboembolic - recurrent microthrombi which dec cross-sectional area of pulmonary vascular bed

V - multifactorial (heme, SLE, metabolic disorders)

Question 2

What pulmonary artery pressure defines pulmonary HTN?

Answer 2

25 mmHg or more at rest

Question 3

What histo changes occur to pulmonary vessels?

Answer 3

Atherosclerosis

Medial hypertrophy

Intimal fibrosis

Plexiform lesions

Question 4

Bosentan

Answer 4

MOA: competitively antagonizes endothelin-1 receptors to dec pulm vascular resistance

Side effects - hepatotoxic (monitor LFTs)

Question 5

Sildenafil

Answer 5

MOA: Inhibits PDE5 - inc cGMP - prolonged NO vasodilation

Question 6

Epoprostenol, iloprost

Answer 6

MOA: PGI2 analogs (prostacyclin) with direct vasodilatory effect and inhibit platelet aggregation

Side effects - flushing, jaw pain

Question 7

What gene is associated w/ inherited pulmonary HTN?

Answer 7

BMPR2

Auto dom inactivating mutation –> smooth muscle / endothelial proliferation

2 hits - this causes predisposition but need 2nd insult to activate the pulmonary vasculature remodeling process