Cardiovascular

Question 1

Stimulation of Beta-1 adrenergic receptors in the heart results in what positive tropic effects?

Answer 1

• inotropic (increases contractility)
• chronotropic (increases heart rate)
• dromotropic (increases rate of conduction through AV node)
• lusitropic (increases relaxation of myocardium during diastole)

Question 2

How does atenolol lower blood pressure?

Answer 2

Suppresses the release of renin from the kidneys

Question 3

What is the mechanism of action of Hydralazine?

Answer 3

Increases cGMP leading to smooth muscle relaxation (to a greater extent in the arterioles than veins)

Question 4

Side effect of papilloedema

Answer 4

Blurry vision

Question 5

What occurs in 2:1 AV heart block?

Answer 5

every other P wave is not conducted through the AV node to get to the ventricles, and thus every other P wave is not followed by a QRS complex

Question 6

What is the mechanism of action of Nicorandil?

Answer 6

Vasodilation through activation of guanylyl cyclase which results in increased cGMP

Question 7

What is the mechanism of action of Warfarin?

Answer 7

Inhibits epoxide reductase preventing Vitamin K from being converted to its activated form

Question 8

What is the mechanism of action of Dabigatran?

Answer 8

Direct thrombin inhibitor (preventing conversion of fibrinogen to fibrin)

D = D

Question 9

What is the mechanism of action of Rivaroxaban?

Answer 9

factor Xa inhibitor (rivarXaban!)

Question 10

How does aspirin exert its antithrombotic effect?

Answer 10

Inhibits formation of thromboxane A2, which prevents platelet aggregation

Question 11

What is the mechanism of action of low molecular weight heparins, such as dalteparin?

Answer 11

Increases antithrombin activity (prevents the conversion of fibrinogen into fibrin)

Question 12

what is the International Normalised Ratio (INR)?

Answer 12

Used by calculating patient prothrombin time (PT) vs control PT. Therefore, directly proportional to PT. E.g. Warfarin increases both.

Question 13

What hypertension medications can cause hyponatraemia?

Answer 13

Thiazide diuretics e.g. Hydrochlorothiazide
ACE inhibitors
Angiotensin receptor blockers
Calcium channel blockers

Question 14

What cranial nerves is the cough reflex mediated by?

Answer 14

CN IX (glossopharyngeal) and X (vagus)

Question 15

What are the ECG features of hypokalaemia?

Answer 15

U waves
small or absent T waves (occasionally inversion)
prolong PR interval
ST depression
long QT

Question 16

Cause of infective endocarditis associated with poor dental hygiene, most common cause in developing countries?

Answer 16

Streptococcus viridans

Question 17

Cause of infective endocarditis associated with patients with prosthetic valves

Answer 17

Staphylococcus epidermidis

Question 18

Cause of infective endocarditis commonly associated with injecting drug users, most common cause worldwide?

Answer 18

Staphylococcus aureus

Question 19

Dressler syndrome

Answer 19

An autoimmune-mediated pericarditis occurring 2-6 weeks after a myocardial infarction

Question 20

Where are the fastest conduction velocities in the heart?

Answer 20

Purkinje fibres

Question 21

Teratogenic

Answer 21

Can cross the placenta e.g. warfarin

Question 22

From what branch of the Circle of Willis does the ophthalmic artery arise?

Answer 22

Internal carotid artery

Question 23

What is the primary event in aneurysmal disease?

Answer 23

Loss of elastic fibres from the media

Question 24

Which cardiovascular condition can Friedreich’s ataxia lead to?

Answer 24

Hypertrophic obstructive cardiomyopathy

Deficiency of the frataxin protein > cardiac neuropathy. [involves damage to the nerves that innervate the heart and changes in cardiac muscle that may lead to hypertrophic obstructive cardiomyopathy]

Question 25

How does the CNS maintain intracranial pressure?

Answer 25

3 components: brain, CSF and blood Skull dimensions cannot be changed Changes in brain volume e.g. tumour can be offset by changes in CSF volume to maintain intracranial pressure

Question 26

Cushing's triad

Answer 26

A triad of symptoms due to increased intracranial pressure. Normally seen in the terminal stages of acute head injury and consists of hypertension, bradycardia and irregular breathing.

Question 27

Culprit artery in most INFERIOR MI cases?

Answer 27

Right coronary artery

Question 28

Culprit artery in ANTERIOR MI cases?

Answer 28

Left anterior descending artery

Question 29

Culprit artery in LATERAL MI cases?

Answer 29

Circumflex artery

Question 30

First line treatment for patients aged <55-years or those with type 2 diabetes

Answer 30

AA: | ACE-inhibitor or angiotensin II receptor blocker (ARB)

Question 31

First line treatment for patients aged over 55-years, or of Afro-Caribbean origin

Answer 31

C: | Calcium channel blocker (CCB).

Question 32

Mechanism of action of thiazide diuretics

Answer 32

Inhibit sodium reabsorption at the beginning of the distal convoluted tubule (DCT) by blocking the thiazide-sensitive Na+-Cl− symporter

Question 33

Common adverse effects of thiazide diuretics

Answer 33

``` dehydration postural hypotension hyponatraemia, hypokalaemia, hypercalcaemia* gout impaired glucose tolerance impotence ```

Question 34

Which part of the cardiac action potential does the ST segment of the ECG relate to?

Answer 34

ST segment = slow calcium influx occurs during phase 2 (plateau) of the cardiac action potential