Pulmonary Hypertension

Question 1

Pulmonary HTN?

Answer 1

Localized HTN in the pulmonary circuit; sustained pulmonary arterial pressure >25 mmHg

Question 2

What is the normal arterial pressure of the pulmonary circuit?

Answer 2

~15 mmHg

Question 3

Does the pulmonary circuit have a high or low resistance? What does this mean?

Answer 3

Lower resistance and is compliant when there is a lower blood pressure

Question 4

Etiology of Pulmonary HTN

Answer 4

• can be r/t cardiac or and/or pulmonary issues
• Increased pulmonary volume
• increased pulmonary venous pressure
• Hypoxemia causing an increase in pressure d/t pulmonary vasoconstriction

Question 5

List an example of increased pulmonary volume.

Answer 5

Cardiac septal defects causing blood in the left ventricle to leak back into the right ventricle through a hole in the interventricular septum that did not close during embryogenesis, resulting in an increased volume of blood traveling through the pulmonary circuit

Question 6

List an example of increased pulmonary venous pressure.

Answer 6

Left ventricle dysfunction causing congestion of blood in the pulmonary vein

Question 7

Explain the pathology of pulmonary HTN

Answer 7

Hypoxemia -> hypoxia in the lung and hypercapnia in the blood -> compensatory vasoconstriction occurs to prevent the spread of increased CO2 throughout the body -> increased pressure within the pulmonary circuit

Question 8

Manifestations of Pulmonary HTN

Answer 8

• dyspnea
• syncope [unexplained neuro mnft]
• chest pain on exertion
• fatigue
• manifestations of right-sided failure
• Right ventricular hypertrophy
• distended pulmonary arteries

Question 9

Syncope?

Answer 9

loss of consciousness

Question 10

Why does chest pain on exertion occur?

Answer 10

increased respirations = increased demand

Question 11

Why do manifestations of right-sided heart failure appear in pulmonary HTN?

Answer 11

Because the right ventricle pumps against resistance d/t increased pressure in the pulmonary artery

Question 12

Why does right ventricular hypertrophy occur in pulmonary HTN?

Answer 12

D/t increased workload requiring increased muscle size and distended pulmonary arteries (increased pressure and blood volume = distention)

Question 13

What is the first line of treatment for pulmonary HTN?

Answer 13

Vasodilators

Question 14

Treatment of pulmonary HTN

Answer 14

• based on the underlying cause

- Vasodilator (Ca+ channel blockers; prostacyclin)

Question 15

Prostacyclin?

Answer 15

A compound that lines the endothelium wall. It prevents blood and other components from sticking to the wall.

Question 16

What are 4 benefits of Prostacyclin?

Answer 16

1. More potent vasodilator compared to calcium channel blockers
2. Results in dilation of the right ventricle (better to dilate the heart than it to hypertrophy)
3. Right atrioventricular valve increases function to prevent regurgitation to prevent right-sided heart failure
4. Also an antithrombotic (not used for this property)