Lecture 13 Pulmonary Arterial Hypertension Flashcards Preview

CDL301 Cardiovascular Pharmacology > Lecture 13 Pulmonary Arterial Hypertension > Flashcards

Flashcards in Lecture 13 Pulmonary Arterial Hypertension Deck (71)
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1

How does systolic pressure in the aorta and pulmonary artery differ

Aortic systolic blood pressure is much higher at 100-140mmHg compared to the pulmonary artery pressure which is around 15-30mmHg

2

Why is the pressure in the pulmonary artery at the level it is

This low pressure is optimum for gas exchange to occur in the lungs. Flow needs to be high but the pressure must remain low

3

What is the clinical definition of pulmonary hypertension

A mean pulmonary artery pressure (PAP) over 25mmHg

4

What is the clinical definition of pulmonary arterial hypertension

This is where there is a mean PAP over 25mmHg but the hypertension is driven by vascular changes. These patients will have a LVEDP below 15mmHg and a pulmonary vascular resistance over 240dyn s-1 cm-5

5

What is the key difference between PH and PAH

PAH is PH but driven solely by vascular changes

6

What intervention is carried out when a patient is suspected of having PH

Right heart cardiac catheterisation. A catheter is inserted into the jugular vein and tracks back to the right atria and right ventricles where it records the blood pressure. The attached balloon then directs the catheter to the pulmonary artery where it takes another recording. These pressures can be used to determine if the patient indeed has PH

7

What is significant about the right atrial pressure

It is roughly the venous pressure between 2-5mmHg

8

What is the average pressure in the right ventricle during systole and diastole

Systolic – 20mmHg and diastolic – 1mmHg

9

What is significant about the pulmonary artery pressure

Systolic pressure is around the same at the right ventricle (20mmHg) but the diastolic pressure increases to around 15mmHg

10

How is mean arterial pressure calculated

Mean Pressure = 2/3 Diastolic Pressure + 1/3 Systolic Pressure

11

Recall the equation for peripheral vascular resistance

PVR = (Mean PAP – PCWP) / CO

12

Recall the equation for mean pulmonary artery pressure

Mean PAP = PVR x CO + PCWP

13

What is meant by pulmonary capillary wedge pressure

PCWP is essential an estimation of left atrial pressure and is also equivalent to the left ventricular end diastolic pressure

14

What is the significant of PCWP in regards to pulmonary hypertension

If the PCWP goes above 15mmHg then a patient is not considered to have pulmonary artery hypertension but pulmonary hypertension due to left side heart disease

15

What oddity is seen in terms of the association of pulmonary hypertension with gender

PH is 4x more prevalent in women yet more severe in males

16

How might a patient with PH present

Progressive exertional breathlessness and chest pain as well as syncopal episodes after exertion

17

What is often seen on the chest X-ray in patients with PH

Normal lungs however there is often an increased pulmonary artery and heart size

18

What sorts of scans are carried out on patient suspected of having PH

Chest X-Ray CT pulmonary angiogram echocardiogram MRI and a Q scan to look at the blood flow

19

PH patients often can have low cardiac output T or F

T

20

What is type 1 PH

Type 1 is classical pulmonary arterial hypertension. Although rare most drugs target this form of the disease

21

What is type 2 PH

Type 2 is pulmonary hypertension due to left heart disease. This often means patients will have problems with left ventricular function but can also be due to problems with the heart valves. This is the most mild form of the disease and as such there are no specific treatments

22

What is type 3 PH

Type 3 is pulmonary hypertension due to lung disease/hypoxia. This is an often mild form of the disease usually seen in patients with COPD

23

What is type 4 PH

Type 4 is known as chronic thromboembolic pulmonary hypertension (CTEPH) and is the only curable form of pulmonary hypertension. This is where blood clots lodge into the pulmonary circulation blocking the flow of blood to a region of the lung. Usually surgical removal of the clot resolves the condition

24

What is type 5 PH

Type 5 is unclear/multifactorial pulmonary hypertension. This is where the cause of the disease is allusive or the result of a combination of factors

25

How can type 1 PAH be subclassified

Idiopathic – accounting for 40% of cases. Heritable – due to mutations in BMPR2 or Alk1. Drug/Toxin Induced – methamphetamine and diet pills. Associated PAH – occurs as a result of connective tissue disease (scleroderma) HIV portal hypertension congenital heart disease or schistosomiasis

26

How can Type 2 pulmonary hypertension due to left heart disease be subclassified

Based on its route cause either due to systolic dysfunction diastolic dysfunction or valvular disease

27

What are some of the specific causes of Type 3 pulmonary hypertension

COPD ILD sleep-disordered breathing alveolar hypoventilation disorders chronic exposure to high altitude or developmental abnormalities

28

What are the most common forms of type 1 PH

Idiopathic and associated PH. These each account for 40% of cases with 10% being the heritable forms

29

What is significant about the drugs fentfluramine and phentamine and PH

These drugs are diet pills that lead to an epidemic of PH in the 1980s

30

Using the graph below discuss the difference in prognosis in patients with PH

There is a massive difference in survival between the subgroups of pulmonary hypertension. Idiopathic pulmonary arterial hypertension (IPAH) has a 5-year survival of 50% yet PAH due to congenital heart disease has an 80% survival rate after 5 years. PAH due to connective tissue disorders has the worst prognosis with a 30% survival rate over 5 years