Cardiovascular

Question 1

Where is tear in aortic dissection?

Answer 1

Tunica intima of the wall of the aorta

Question 2

What is the normal resting membrane potential of the heart’s ventricular and atrial fibres?

Answer 2

Approximately -90mV in the ventricular fibres and -80mV in the atrial fibres

Question 3

Down’s syndrome is associated with what congenital heart anomaly?

Answer 3

Ventricular septal defect

Question 4

What are features of aortic regurgitation?

Answer 4

• Early diastolic murmur
• Collapsing pulse - The carotid pulse rises rapidly due to the vigorous ejection of blood from an overloaded left ventricle. It then falls rapidly due to the backflow of blood into the left ventricle.
• Wide pulse pressure

Question 5

What effect does increased stroke volume have on pulse pressure?

Answer 5

Increases pulse pressure

Question 6

What is arrhythmogenic right ventricular cardiomyopathy characterised by?

Answer 6

Right ventricular myocardium replaced by fatty and fibrofatty tissue

Question 7

An undersized blood pressure cuff may lead to an _____ of blood pressure

Answer 7

overestimation

Question 8

What is torsades de pointes a form of?

Answer 8

Polymorphic ventricular tachycardia

Question 9

What medication is used first-line for reducing stroke risk in AF?

Answer 9

DOACs such as edoxaban

Question 10

From where do the internal thoracic arteries arise from?

Answer 10

The subclavian arteries

Question 11

What is the mechanism of action of nitrate drugs?

Answer 11

Nitrates can cause a decrease in intracellular calcium, due to release of nitric oxide. This nitric oxide activates guanylate cyclase to convert GDP to cGMP. Decreased intracellular calcium within smooth muscles causes relaxation of vascular smooth muscle.

Question 12

What are ECG findings of Wolff-Parkinson-White syndrome?

Answer 12

• Delta wave - slurred upstroke of QRS complex
• Short PR interval

Question 13

What is a range of normal stroke volumes?

Answer 13

55-100ml

Question 14

What is S4 caused by?

Answer 14

The atria contracting forcefully in an effort to overcome an abnormally stiff ventricle

Question 15

What are potential treatment options for postural hypotension?

Answer 15

• Midodrine
• Fludrocortisone

Question 16

What process (not specific to vasculature) is mediated by a2 adrenoceptors?

Answer 16

Platelet aggregation

Question 17

What is a normal ejection fraction range?

Answer 17

50-55%

Question 18

At which point of the cardiac cycle does the highest volume of blood flow through the coronary arteries and why?

Answer 18

Ventricular diastole - During diastole, the backflow of blood from the aorta to the left ventricle causes the aortic valve to close. The cusps of the aortic valve hence move away from the openings of the coronary arteries and therefore allow blood into the coronary arteries, so blood flow is highest during ventricular diastole.

Question 19

Which phase of the cardiac cycle does the beating of the carotid/radial pulse correspond with?

Answer 19

Ventricular systole

Question 20

In aortic pressure tracings, an incisura or dicrotic notch is seen at the end of systole.

What is the cause of this dicrotic notch?

Answer 20

The closure of the aortic valve

Question 21

What is the effect of BNP on preload and afterload?

Answer 21

Decreases both

Question 22

How does BNP decrease afterload?

Answer 22

By decreasing SVR

Question 23

How does BNP decrease preload?

Answer 23

By increasing diuresis which leads to a reduction in blood venous volume and hence reduces preload