Cardiovascular Therapeutics 3

Question 1

What is arrhythmia?

Answer 1

A problem with heart rate or rhythm.

Question 2

Types of arrhythmia

Answer 2

Bradycardia - slowed heart rate (below 60 BPM)
Tachycardia - increased heart rate (over 100 BPM)

Question 3

Symptoms of atrial fibrillation

Answer 3

Breathlessness
Chest discomfort
Syncope or dizziness
Reduced exercise tolerance
Palpitations

Question 4

What are the differences will the ECG of atrial fibrillation have compared to a normal sinus rhythm?

Answer 4

No P-waves
Chaotic baseline
Irregular ventricular rate
The ventricular rate is often 160–180beats per minute
The ventricular complexes look normal

Question 5

Role of ectopic beats in arrhythmias like atrial fibrillation.

Answer 5

These ectopic impulses trigger abnormal atrial depolarisations, initiating episodes of AF.

Question 6

Role of re-entrant circuits in arrhythmias like atrial fibrillation

Answer 6

In AF, multiple micro re-entrant circuits form throughout the atria.

This leads to chaotic, disorganised atrial electrical activity, with rapid, irregular firing.

The AV node filters these signals, leading to the classic irregularly irregular ventricular response

Question 7

Mechanism of action of beta blockers used for rate control in AF

Answer 7

Block action of noradrenaline on the heart prevents tachyarrhythmias

Question 8

Mechanism of action of calcium channel blockers used for rate control in AF

Answer 8

Block L-Type VGCC

Question 9

Types of rhythm control

Answer 9

Electrical
Pharmacological

Question 10

What is recommended for preventing strokes in AF?

Answer 10

DOACS (Direct oral anticoagulants)
Factor Xa inhibitors (rivaroxaban, apixaban, edoxaban)
Factor IIa (a.k.a.a thrombin) inhibitors

Question 11

Factors that contribute to thrombosis (Virchow’s triad)

Answer 11

Blood stasis
Endothelial Damage
Hypercoagulability