Pulmonary Htn

Question 1

What is the formula for pulmonary pressure?

What can increase pulmonary pressure?

Answer 1

P PA= (COxPVR) + P LA

Increase in either CO, left atrial pressure, or PVR can increase pulmonary pressure

CO: R to L shunt, cirrhosis, anemia

Left heart disease

PVR: destruction of pulm vascular bed (ILD, PE)
 hypoxic vasoconstriction (COPD, high altitude)
 small pulmonary artery/arteriole vasculopathy
 medial hypertrophy, intimal thickening, plexiform lesion, in situ thrombosis

Question 2

What are the 4 categories of causes of PAH?

Answer 2

Idiopathic

Heritable

Drug & toxin induced

Associated: conn tissue disorders, congenital heart disease, portal htn, HIV, schistosomiasis, chornic hemolytic anemia

Question 3

Why is pulmonary hypertension have such a bad prognosis?

Answer 3

Because the RV is not as strong: more compliant, less energy expenditure, crescent shaped

Increases in RV afterload are catastrophic

Question 4

What’s the pathway to cardiogenic shock secondary to increase in RV afterload?

Answer 4

Question 5

What does PAH do to gas exchange and ventilation?

Answer 5

Gas exchange: V/Q mismatch, R to L shunt, diffusion abnormalities

Ventilation: increased dead space ventilation

Question 6

What are the symptoms of PAH?

Answer 6

low perfusion –> dyspnea, fatigue, chest pain, palpitations, lightheadedness, syncope

congestion –> abdominal pain & fullness, peripheral edema

Question 7

What are physical exam findings of PAH?

Answer 7

hypoxemia, tachycardia, hypotension

JVD, hepatojugular reflux

RV heave, split S2, loud P2, systolic TR murmur, diastolic PR murmur, RV S3, RV S4

Hepatomegaly, pulsatile liver, ascites

Cool extremities, lower extremity edema

No significant rales in pure PAH

Question 8

What’s the CHX look like in pure PAH?

Answer 8

No pulmonary edema

Question 9

What is the natural progression of PAH?

Answer 9

Compensated: CO remains normal, PAP increases

Decompensated: symptomatic, CO begins to decrease, PAP increases

Overt right heart failure: CO decline, PAP decline due to decline in CO

Question 10

What are the treatment options for PAH?

Answer 10

Calcium channel blocker for vasoresponders - those who respond to short-acting vasodilator (epoprostenol, adenosine, NO)

• *Prostanoids**: act through cAMP to increase vasodilation, antiproliferation, inhibit platelet aggregation; improve hemodynamics, functional capacity, and survival
• epoprostenol IV, trepostinil (SC, IV, inhalation), iloprost (inhalation)
• *Phosphodiesterase 5 inhibitors**: work through inhibition of cGMP phosphodiesterase –> vasodilation & antiproliferation; improve hemodynamics & functional capacity
• sildenafil (PO, IV), tadalafil (PO)
• *Endothelin receptor antagonists**: prevent vasoconstriction & smooth muscle cell proliferation; improve hemodynamics & functional capacity
• bosentan, ambrisentan (PO)

Question 11

What are the side effects of vasodilators that you should worry about?

Answer 11

decrease SVR –> systemic hypotension

Worsen V/Q matching –> hypoxemia

Abrupt medication withdrawal –> rebound pulmonary htn

Increase pulmonary capillary pressure –> pulmonary edema (bc the pressures in the heart remain high but you’ve decreased pulmonary pressure –> pumps blood really hard!)

Question 12

What are the side effects of vasodilators?

Answer 12

HA, dizziness, flushing, nasal congestion secondary to vasodilation

ERAs: teratogenic, peripheral edema, anemia

Bosentan - liver toxicity

Prostenoids: jaw pain, delivery system problems

Question 14

What are the general treatment measures of PAH?

Answer 14

Optimize preload to make RV smaller: diuretics, salt restriction

Supplemental O2: O2 sat >90%

Anticoagulation

Digoxin to improve contractility

Cardiopulmonary rehab

Question 15

What surgical therapies are availbale for PAH?

Answer 15

Lung transplant

Pulm thrombectomy

Atrial septostomy: prob not good