5.7 Understanding Dyspnoea

Question 1

Chronic dyspnoea timeframe

Answer 1

4-8 weeks

Question 2

Is dyspnoea a disorder?

Answer 2

• No
• It is a symptom of a disorder

Question 3

What is deconditioning? How does it cause dyspnoea?

Answer 3

• Unfitness and inactvity
• Under such conditions, the body cannot deliver oxygen as well, and so dyspnoea ensues

Question 4

Cardiac causes of dyspnoea

Answer 4

• Cardiomyopathy
• Valvulopathy
• Pulmonary hypertension
• Pericardial disease
• Arrythmia
• Coronary artery disease
• Intracardiac shunts

Question 5

What is cardiomyopathy?

Answer 5

Reduced effectiveness of heart pump (systolic/diastolic for not contracting or relaxing)

Question 6

Systolic/diastolic cardiomyopathy and hfpef/hfref

Answer 6

Systolic: hfref
Diastolic: hfpef

Question 7

How does pericardial effusion lead to dyspnoea

Answer 7

• Compressed heart
• Heart cannot expand
• Reduced RV filling
• Poor blood flow to lung -> dyspnoea

Question 8

How can arrhythmias cause dyspnoea?

Answer 8

• Slow HR can cause reduced CO
• If fast heart rate, cardiac output reduces due to rhythm disturbance and pulmonary oedema occurs

Question 9

How can CAD lead to dyspnoea?

Answer 9

• Less O2 to heart muscle
• LV can’t pump as well
• Pulmonary oedema

Question 10

How can intracardiac shunts cause dyspnoea?

Answer 10

When blood flows from right to left, deoxygenated blood flows throughout the systemic circulation, leading to hypoxaemia.

Question 11

How can deconditioning cause dyspnoea?

Answer 11

• Muscles don’t use oxygen as effectively
• More anaerobic metabolism -> lactate
• Interpreted as shortness of breath

Also: decreased muscle perfusion and decreased mitochondrial density

Question 12

List three causes of anaemia

Answer 12

• Haemolysis
• Iron deficiency
• Haemorrhage

Question 13

Most common cause of anaemia

Answer 13

Iron deficiency

Question 14

How much iron in the average well-nourished person?

Answer 14

3g

Question 15

Anaemia dyspnoea mech

Answer 15

• Reduced oxygen supply
• Leads to hypoxaemia

Question 16

How can cancer cause anaemia?

Answer 16

• Increased inflammatory cytokines
• Leads to shortened RBC survival
• Suppressed RBC production
• Alterations in iron metabolism

Question 17

Describe haemolytic anaemia

Answer 17

• RBCs destroyed quicker than produced

Question 18

Intrinsic vs extrinsic haemolytic anaemia

Answer 18

Intrinsic: Abnormal haemoglobin/RBC membrane abnormalities; cells are rigid, and get trapped

Extrinsic: Normal RBCs, damaged by external factors (e.g. toxins, heart valves, mechanical injury)

Question 19

“My breathing is shallow”

Answer 19

Pulmonary fibrosis

Question 20

“I feel an urge to breathe more”

Answer 20

Hypoexaemia/pulmonary fibrosis

Question 21

“My chest is constricted”

Answer 21

Pulmonary fibrosis, oedema

Question 22

“I feel a hunger for more air”

Answer 22

Pulmonary oedema, pulmonary fibrosis, hypoxia/hypercapnia

Question 23

“By breath does not go in all the way”

Answer 23

• Might be chest wall/lung disease
• If not, almost always anxiety

Question 24

“I feel I am suffocating”

Answer 24

Pulmonary oedema

Question 25

Patient presents with breathlessness after driving to Melbourne. What is the first thought?

Answer 25

Pulmonary embolism

Question 26

Bilateral pleural effusion is almost always…

Answer 26

Heart failure