Cardiology

Question 1

Why can Rosuvastatin but not Atorvastatin be used in HIV patients on Protease inhibitors?

Answer 1

Atorvastatin is metabolised by the CYP3A4 enzyme.
This enzyme is downregulated by Protease inhibitors, which means Atorvastatin levels are increased.

Question 2

Which of the following medications need caution when using with Rivaroxaban?
Sotalol
Metoprolol
Amiodarone
Diltiazem
Digoxin

Answer 2

Diltiazem
Impairs with the metabolism of Rivaroxaban via inhibition of CYP3A4 and P-glycoprotein, causing increased levels

Question 3

What did the RIVAL study conclude with regards to radial vs femoral access for acute coronary syndromes?

Answer 3

RIVAL study demonstrated that radial access is non-inferior to femoral access with respect to death, MI, stroke and non-CABG-related bleeding, HOWEVER, radial access is associated with significantly LOWER vascular complications.

Question 4

What do the following parts of the JVP wave indicate?
a
c
v
x
y

Answer 4

‘a’ wave = atrial contraction ( a for atrial)
– large if atrial pressure e.g. tricuspid stenosis, pulmonary stenosis, pulmonary hypertension
– absent if in atrial fibrillation

‘c’ wave (c for closure)
– closure of tricuspid valve
– not normally visible

‘v’ wave (v for volume filling)
– due to passive filling of blood into the atrium against a closed tricuspid valve
– giant v waves in tricuspid regurgitation

‘x’ descent = fall in atrial pressure during ventricular systole

‘y’ descent = opening of tricuspid valve

Question 5

What do Cannon ‘a’ waves mean?
When are they seen?

Answer 5

– caused by atrial contractions against a closed tricuspid valve
– are seen in complete heart block, ventricular tachycardia/ectopics, nodal rhythm, single chamber ventricular pacing.

Question 6

What is the mechanism of action of clopidogrel, prasugrel or ticagrelor?
How is ticagrelor different to clopidogrel?

Answer 6

P2Y12 inhibitors
Similar to clopidogrel, ticagrelor also inhibits ADP receptors of subtype P2Y12. However, ticagrelor acts differently in the way that it has a binding site which is different from ADP, making its inhibition reversible. Moreover, it does not require hepatic activation of CYP2C19 as compared to clopidogrel.

Question 7

Which trial proved oxygen therapy does harm in non-hypoxic STEMI patients?

Answer 7

Air Versus Oxygen in ST-Segment Elevation Myocardial Infarction (AVOID) trial

Question 8

What murmurs are heard in each of the following scenarios?
Early systolic -
Midsystolic ejection -
Holo/pansystolic -
Late systolic -
Early diastolic -
Mid-diastolic -
Late-diastolic -

Answer 8

Timing of systolic murmurs:
Early systolic- MR, TR, VSD
Midsystolic ejection- Aortic stenosis, Aortic sclerosis.
Holo/Pansystolic – MR, TR, VSD
Late systolic- Mitral valve prolapse, Tricuspid valve prolapse
Timing of Diastolic murmur:
Early diastolic – AR, PR
Mid-diastolic- MS, TS, Atrial myxoma
Late diastolic- MS, TS, Atrial myxoma, Complete heart block.

Question 9

What is the mechanism of action of Evolocumab?
What percentage does it reduce LDL by?

Answer 9

PCSK9 inhibitor
~60%

Question 10

Mechanisms of action of lipid lowering medications:
Ezetimibe?
Statin?
Evolucumab?

Answer 10

Ezetimibe– blocks biliary NPC1L1
Statin– Inhibits the HMG-CoA reductase enzyme
Evolucumab/Alirucumab– Monoclonal antibodies that interferes with the binding of PCSK9 to the LDL-receptor.

Question 11

What coronary artery is most likely to be involved in an acute aortic dissection?

Answer 11

Right coronary.
right anterior aspect of the ascending aorta above the right sinus of Valsalva.

Question 12

How does simvastatin work?

Answer 12

competitive inhibitors of HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis.
This inhibition leads to reduced cholesterol synthesis in the liver, prompting upregulation of LDL receptors and increased clearance of LDL from the bloodstream.

Question 13

Mechanism of action of Tirofiban?
Does Abciximab have the same or different action?

Answer 13

Reversible inhibitor of Glycoprotein IIb/IIIa receptor on platelets
Abciximab = same

Question 14

About half of all patients with Hypertrophic Cardiomyopathy (HCM) have a positive family history compatible with autosomal dominant transmission.
What is the most common mutation?
Second most common?
myosin light chain
cardiac myosin binding protein c
cardiac troponin C
cardiac beta-myosin heavy chain gene on chromosome 14.
cardiac alpha myosin heavy chain

Answer 14

Most common = cardiac myosin binding protein c
Second most common = cardiac beta-myosin heavy chain

Question 15

Which of the following is the strongest indication for an ICD placement in a patient with HOCM?
Syncope following intense exercise
Left ventricular wall thickness equal to or more than 30 mm.
Abnormal blood pressure response to exercise
Evidence of myocardial ischaemia
Left ventricular outflow tract obstruction

Answer 15

LV wall thickness >30mm

Question 16

What are the 4 most common ECG changes seen in WPW syndrome

Answer 16

Shortened PR interval:
Delta wave:
Widened QRS complex:
T-wave changes: TWI may be seen in leads where the QRS complex is positive.

Question 17

What is the accessory pathway in WPW known as?

Answer 17

bundle of Kent

Question 18

Mechanism of action of Digoxin, specifically how it causes increased cardiac contractility?

Answer 18

Inhibiting the sodium-potassium ATPase pump in myocardial cells.
Inhibition leads to an increase in intracellular sodium concentration, which subsequently increases intracellular calcium concentration via the sodium-calcium exchange mechanism.
Increase in intracellular calcium enhances cardiac contractility

Question 19

Are Verapamil and Diltiazem non-dihydropyridine or dihydropyridine calcium-channel blockers?

Answer 19

NON-dihydropyridine

Question 20

Which anti-platelet medications are reversible?

Answer 20

ALL anti-platelets are IRREVERSIBLE except for Tirofiban and Ticagrelor.

Question 21

Spontaneous coronary artery dissection:
Women or men?
Age?
How common for causes of MI?
Most common artery involved?
Underlying disease?

Answer 21

Women
usually aged between 47 and 53 years.
<1% of all acute MIs.
LAD and its branches are the most commonly affected vessel.
Underlying systemic arteriopathy such as fibromuscular dysplasia.

Question 22

Brugada Syndrome:
Inheritance?
Mechanism?
Presentation?
Ethnicity?
Treatment?

Answer 22

Autosomal dominant condition.
Due to sodium channel defect
Presents with syncope, cardiac arrest or sudden cardiac death.
More common in south east Asian males.
Only treatment is ICD implantation.

Question 23

How many types of long QT syndrome are there?
Which is most strongly associated with exercise?
Sleep?
Emotional?
SCN5A gene?

Answer 23

Three types
Exercise - 1
Sleep - 3
Emotional - 2
SCN5A - type 3

Question 24

Which syndrome has a gain of function in SCN5A gene and which has a loss?
Brugada vs LQTS type 3?

Answer 24

Loss = Brugada
Gain = LQTS type 3

Question 25

Arrhythmogenic RV dysplasia (ARVD):
Autosomal dominant or recessive?
Pathogenesis?
Diagnosis?
Most common ECG changes?

Answer 25

Autosomal dominant
Patho = Fibro-fatty infiltration of right ventricle leading to poor RV function BUT preserved LV function
Dx = cMRI or RV angiography
ECG - T wave inversion V1-3

Question 26

Which cytochrome P450 is linked to Clopidogrel?
Which demographic is most likely to have a mutation in this?
CYP2C19
CYP2B20
CYP420B

Answer 26

CYP2C19
East Asian / Han Chinese

Question 27

What valve is involved in Ebstein’s anomaly?

Answer 27

Tricuspid

Question 28

Rheumatic heart disease:
More likely in men or women?
Which valve most common?
What infection causes it?
Diagnosis?
Treatment?

Answer 28

Gender: Males > females
Valve: MV > AV (20-30%) > TV > PV
Lesion: MR > MS > AS
Infection: Group A Strep pharyngitis
Testing: streptolysin O +Ve
Treatment: Prophylaxis = IM Penicillin G monthly for 10yrs. If HF/Valve disease per guidelines +/- replacement

Question 29

A 28-year-old woman, who emigrated from Cambodia 10 years ago, presents to the emergency department in Auckland with a three-week history of increasing shortness of breath, orthopnoea, nocturnal dyspnoea and ankle oedema. She is 25 weeks pregnant and has no significant past medical history. The presence of pulmonary oedema is confirmed clinically and radiologically. She responds well to intravenous frusemide but remains tachypnoeic with a heart rate of 120/minute in sinus rhythm. Her blood pressure is 125/85 mmHg. Echocardiography demonstrates mitral stenosis with an estimated valve area of 1.3 cm2 and a left atrial diameter of 50 mm.

What is the most appropriate next step in management?

Balloon valvotomy
Surgical valvotomy.
Beta-blocker therapy
Angiotensin converting enzyme (ACE) inhibitor therapy.
Calcium blocker therapy

Answer 29

Beta blocker

In mitral stenosis, the left atrial enlargement and elevated pressure reflect the restricted flow through the stenotic mitral valve. A fast heart rate reduces diastolic filling time, exacerbating the volume and pressure overload in the left atrium, leading to increased pulmonary pressures and risk of pulmonary oedema. By slowing the heart rate, beta-blockers increase the diastolic filling time, thereby reducing pulmonary congestion and the symptoms of heart failure.

Although this patient remains in sinus rhythm, individuals with mitral stenosis are at an increased risk of developing atrial fibrillation due to left atrial enlargement and strain. Beta-blockers can help prevent the onset of atrial fibrillation and are beneficial in controlling the ventricular rate if atrial fibrillation were to occur.

Question 30

Which of the following cardiovascular condition is associated with the highest rate of maternal mortality?

aortic regurgitation
pulmonary hypertension.
peripartum cardiomyopathy
coarctation.
hypertrophic cardiomyopathy.

Answer 30

pulmonary hypertension

Question 31

Which of the following maternal conditions is associated with the greatest risk of cardiac complications during pregnancy?

Ventricular septal defect.
Patent ductus arteriosus
Eisenmenger syndrome
Mitral valve prolapse
Atrial septal defect

Answer 31

Eisenmenger syndrome.

The triad of congenital systemic-to-pulmonary communication, pulmonary arterial disease and cyanosis is called Eisenmenger syndrome.

Eisenmenger syndrome can occur with unrepaired ASD, VSD, PDA, or more complex cardiac lesions when progressive pulmonary vascular disease leads to intracardiac shunt reversal or bidirectional shunting.
Regardless of etiology, pregnancy in the Eisenmenger syndrome is associated with major morbidity and mortality.
Because of the high risk of maternal mortality, pregnancy is contraindicated in women with Eisenmenger syndrome.

Question 32

Mechanism of action of Bosentan?

Answer 32

Competitive antagonist of endothelin-1.
Under normal conditions, endothelin-1 binding of ET-A receptors causes constriction of the pulmonary blood vessels.

Question 33

Does ARNI increase BNP or NT-pro-BNP?

Answer 33

ARNI → increased BNP, normal NT-pro-BNP

Question 34

Is Ticagrelor or Clopidogrel reversible?
Which one has a longer half life?

Answer 34

Ticagrelor is reversible
Ticagrelor has a longer half life