Cardiology

Question 1

Which drug can be used with echocardiography to induce cardiac stress (i.e. in a stress echocardiogram)

Answer 1

Dobutamine - B1 agonist

Question 2

With regards to the ischaemic cascade - which of the following occurs first?
A. Diastolic dysfunction
B. Regional Systolic dysfunction
C. ECG changes
D. Chest Pain

Answer 2

Ischaemia > Diastolic Dysfunction > Regional Systolic Dysfunction (Wall Motion Abnormality) > ECG Changes > Chest Pain

Question 3

What is the most common valvular heart lesion?

Answer 3

Aortic Stenosis
- present in ~12% of people aged over 75
- mostly degenerative
- bicuspid AV in ~1% of population
- also post RHD and radiation

Question 4

With regards to AS - what echocardiograph methods can be used to assess severity. What are the numerical thresholds that delineate severe disease.

Answer 4

AS Jet Velocity - 4m/s
Mean Gradient - 40mmHg
Valve Area - < 1cm^2

Question 5

Describe the pathogenesis of Rheumatic Heart Disease

Answer 5

Systemic Immune Response to beta-haemolytic streptococcal infection

Predominant mitral disease, also aortic and triscuspid, rarely pulmonary.

87% of RHD in Australia is in ATSI peoples

High stroke risk with AS - CHADVASC not relevant

Question 6

With regards to MS - what echocardiograph methods can be used to assess severity. What are the numerical thresholds that delineate severe disease.

Answer 6

Valve area <1- 1.5cm^2
Mean gradients >10mmHg
Pulmonary artery pressure > 50mmHg

Question 7

With regards to assessment of RV systolic pressure, the Bernoulli Equation states…

Answer 7

Change in pressure across an orifice is proportional to the square of the velocity of the fluid flowing through the orifice.

Change in p = 4V^2

The velocity of TR jet is proportional to RVSP
RVSP = 4(TR velocity)^2 + right atrial pressure