CVD - ATRIAL FIBRILATION Flashcards
What are the symptoms of AF?
Heart palpitations, dizziness, SOB, tiredness
What are the 3 categories of AF?
Paroxysmal - episodes stop 48 hours without treatment
Persistent - episode lasts > 7 days
Permanent - present all the time
What is the general treatment for AF?
Rate control - BB or rate limiting CCB and monotherapy. If uncontrolled then dual therapy. If still uncontrolled then rhythm control
Rhythm control - pharmacological (e.g. amiodarone) or electrical (direct current cardioversion)
How long should you wait until the patient is fully anti-coagulated for before a cardioversion?
3 weeks
If monotherapy fails, which drugs can be used in combination as second line?
BB, Digoxin, Diltiazem
Which drugs are used in rhythm control to maintain sinus rhythm post-cardioversion?
Sotalol, Flecainide, Propafenone, Amiodarone
Why should you avoid verapamil in patients being treated with beta blockers?
Increased risk of severe hypotension and asystole
What does CHADSVAS stand for and what are the scores?
Congestive HF - 1
Hypertension - 1
Age > 75 - 2
Diabetes - 1
Stroke - 2
Vascular disease - 1
Age 65-74 - 1
Sex (female) - 1
After doing CHADVAS when would you decide to give an anticoagulant?
If the score is 2 or more
Which anticoagulant would you give in new onset AF?
Parenteral anticoagulant e.g. heparin
Which anticoagulant would you give if AF was diagnosed already?
Warfarin or NOAC
What would you do if a patient had unstable sustained ventricular tachycardia?
direct current cardioversion
What would you do if a patient had stable sustained ventricular tachycardia?
IV anti-arrhythmic drug. Amiodarone preferred
What would you give if a patient had non-sustained ventricular tachycardia?
beta blocker
What is the treatment of Torsades De Pointes?
IV magnesium sulphate
What can cause Torsades De Pointes?
Sotalol, Severe Bradycardia, Hypokalaemia
What are the stages to treating paroxysmal supraventricular tachycardia?
1) terminates spontaneously or with reflex vagal nerve stimulation (carotid sinus massage or immerse face in ice cold water)
2) IV adenosine (contraindicated in COPD/asthma)
3) IV verapamil
What is normally the loading dose for amiodarone?
200mg TDS 7 days
200mg BD 7 days
200mg OD as maintenance
What are the side effects of amiodarone?
Eyes - corneal microdeposits (night time glares when driving), optic neuropathy (stop amiodarone if this occurs)
Skin - phototoxicity, slate-grey skin on light exposed areas (shield skin from light during treatment and use high SPF even after stopping)
Nerves - peripheral neuropathy (numbness, tingling, tremors)
Lungs - pneumonitis, pulmonary fibrosis, SOB, cough
Liver - hepatotoxicity
Thyroid dysfunction - hypothyroidism (give carbimazole if needed and withdraw amiodarone), hyperthyroidism (give levo if needed without withdrawing amiodarone)
What do you need to monitor if a pt is on amiodarone?
Annual eye test, CXR before treatment, LFTs every 6 months, monitor TSH, T3 and T4 before treatment and every 6 months, BP and ECG (causes hypotension and bradycardia), serum potassium (can cause hypokalaemia)
Amiodarone has a very long half life. What are some interactions?
Enzyme inhibitors - increase cp
Other CYP substrates (e.g. warfarin, digoxin, phenytoin) - amiodarone itself acts as an inhibitor
Statins - increased risk of mypopathy
BB, verapamil, diltiazem - bradycardia, AV block, myocardial depression
Drugs that prolong QT - e.g. Quinolones, Macrolides, TCAs, SSRIs, Lithium, Quinine, Hydroxychloroquine, Antimalarials, Antipsychotics
What are the therapeutic levels for digoxin?
1-2 mcg/L
When do you need to measure digoxin levels?
If toxicity is suspected
If the patient is renally impaired
How is digoxin dosed?
Loading dose required due to long half life and to get the desired effect
Maintenance dose OD
Atrial flutter and non paroxysmal AF = 125-250 mcg
Worsening or severe heart failure = 62.5-125 mcg
What are the bioavailabilities for digoxins different formulations?
Elixir - 75%
Tablet - 90%
IV - 100%
What can cause digoxin toxicity?
Hypo K+, Mg+
Hyper Ca 2+
Hypoxia
Renal impairment
What are the symptoms of digoxin toxicity?
Bradycardia/heart block
Nausea and vomiting
Blurred or yellow vision
Confusion/delirium
Rash
What interacts with digoxin?
Diuretics, B2 agonists, steroids, theophylline - cause hypo K+ so causes digoxin toxicity
Inhibitors - increased cp
Inducers - decreased cp
NSAIDs, ACE, ARB - reduce renal excretion so lead to toxicity
