CPRS Case 1: Atrial fibrillation

Question 1

Understand anatomy and physiology of normal cardiac conduction system

Answer 1

See lecture

Question 2

Understand basic principles of 12-lead ECG recording

Answer 2

See lecture + physiology practical

Question 3

Describe mechanisms of action, side effects, CI of rate-controlling agents

Answer 3

See lecture Antiarrhythmic drugs

Rate-controlling:
Class II: Beta blocker
Class IV: Calcium channel blocker
Cardiac glycoside: Digoxin

Question 4

Mechanism of action, SE and CI of oral anticoagulants

Answer 4

Warfarin:

• inhibit Vitamin K epoxide reductase + Vitamin K quinone reductase
• Vitamin K epoxide —not reduced—> Vitamin K hydroquinone
• No Vitamin K hydroquinone to be oxidised —> no activation of clotting factors
• Narrow therapeutic index
• Bleeding
• Hepatcially eliminated —> interaction with other drugs

NOACs:

• direct thrombin inhibitor / factor Xa inhibitor
• rapid onset
• short half-lives
• routine monitoring less important
• Renally eliminated

Question 5

Diagnostic approach to palpitations

Answer 5

1. Manual pulse palpation to assess presence of irregular pulse in
   - breathlessness
   - palpitations
   - transient ischaemic attack
2. ECG in all people if irregular pulse detected
3. Transthoracic echocardiography
4. Transoesophgeal echocardiography

Question 6

Risk factors, presentation and complications of atrial fibrillation

Answer 6

Risks factors:

• > 60
• DM
• Hypertension
• Congestive heart failure
• Structural heart disease
• Coronary artery disease
• Prior heart attacks

Presentation:

• Palpitations
• Breathlessness
• Transient ischaemic attack
• Syncope
• Chest pains
• Fatigue

Complications:

• Stroke
• Heart failure

Question 7

Principles of management of atrial fibrillation

Answer 7

Acute presentation:

• life-threatening —> emergency electrical cardioversion
• non-life threatening —> pharmacological cardioversion (amiodarone)

Drug treatment:
1. Rate control drugs:
—> symptoms not controlled by 2 rate-control drugs —> rhythm control
2. Anticoagulation drugs (Stroke prevention):
—> CHAD2S2-VASc assessment tool for stroke risk
—> HAS-BLED tool for bleeding risk

Question 8

Promote cessation of health-risk behaviours in primary care setting

Answer 8

• Smoking cessation (see lecture)

- reduce alcohol intake

Question 9

Disease burden of atrial fibrillation for patient and society

Answer 9

1. Most common heart rhythm disorder in the world
   - increase risk of morbidity and mortality
   - risk of stroke
   - risk of heart failure
2. Life-long chronic disease
3. Quality of life is significantly poorer
   - disability
   - high number of drugs
   - anxiety
   - disease progression
4. Caring for family members with AF
5. Limitations after stroke
   - cognitive impairment
   - problem with communication
   - paralysis
6. Financial burden on healthcare system
   - cost of treatment and prevention is high

Question 10

Principles of screening for health condition

Answer 10

• Presumptive identification of unrecognised disease in apparently healthy asymptomatic population by means of tests that can be applied easily to target population

1. systematic invitation + follow-up
2. participation > 70% of target population
3. necessary infrastructure and resource to offer the test and adequately diagnose
4. robust monitoring and valuation framework to assure quality

• undertaken only when effectiveness is demonstrated
• resources are sufficient to cover all target group
• treatment and follow up ensured with abnormal results
• prevalence is high enough to justify cost and effort of screening

For atrial fibrillation, opportunistic screening > targeted screening

Question 11

4 basic principles of medical ethics in patient management

Answer 11

1. Respect for autonomy
2. Non-maleficence
3. Beneficence
4. Justice