Atrial Fibrillation Flashcards
Define atrial fibrillation [1]
sustained cardiac arrthymia caused by the chaotic electrical activity of the atria being conducted to the ventricles in a random manner
What are the symptoms of atrial fibrillation [6]
- may be asymptomatic
- palpitations
- dysponea
- rarely, chest pain
- rarely, syncope (loss of consciousness)
- may present with complications: stroke
How is the pulse typically described in atrial fibrillation? [1]
irregular irregular
What are the 3 types of presentation of atrial fibrillation? [3]
- paroxysmal (intermittent)
- persistent
- permanent
*can progress from paroxysmal fibrillation to persistent
What type of ECG may be needed to detect paroxysmal atrial fibrillation? [1]
prolonged ambulatory ECG (of lead I)
What are the typical features of an ECG in a patient with atrial fibrillation? [3]
- irregularly irregular rate (rate variable)
- irregular, narrow QRS
- no P waves
What condition is this? [1]
Atrial fibrillation
Define atrial flutter and its basic pathogenesis [2]
- A type of abnormal heart rate, or arrhythmia.
- It occurs when the atria beat faster than the ventricles, causing the heart rhythm to be out of sync
What are the typical features of an ECG in a patient with atrial flutter? [4]
- rate variable
- regular narrow QRS
- sawtooth atrial activity at 300bpm seen in leads II, III, aVF (in the inferior part of the heart)
- variable AV block
What are the potential complications of atrial flutter? [2]
risk of embolism and thrombosis
Name the conditions predisposing to, or encouraging progression of atrial fibrillation [11]
- hypertension
- symptomatic heart failure (NYHA class II-IV) including tachycardiomyopathy
- valvular heart disease
- cardiomyopathies
- atrial septal defect (and other congenital heart defects)
- coronary artery disease
- thyroid dysfunction
- obesity
- diabetes mellitus
- COPD and sleep apnoea
- chronic renal disease
What are the objectives of treatment of atrial fibrillation? [5]
- prevention of stroke
- symptom relief
- optimum management of associated CV disease
- rate control
- +/- correction of rhythm disturbance
What are the essential investigations given to a patient with suspected AF? [4]
- ECG
- echocardiogram
- thyroid function tests (TFTs)
- liver function tests (LFTs)
What are the AF guidelines on rate control? [6]
- target heart rate: <110/min
- if still symptomatic, aim for heart rate <80/min
- patients without heart failure should be started on either:
- a beta blocker (bisoprolol/atenolol) or
- rate-limiting Ca2+ antagonist (verapamil)
- do not use beta-blocker & verapamil together - makes the heart rate too slow
- digoxin as second-line
What are the major risk factors for stroke and thromboembolism in non-valvular AF? [3]
- previous stroke
- transient ischaemic attack (TIA)
- age ≥ 75 years
What are the clinically-relevant non-major risk factors for stroke and thrombo-embolism in non-valvular AF? [7]
- chronic heart failure
- moderate to severe left ventricular systolic dysfunction
- e.g. left ventricular ejection fraction (LV EF) ≤ 40%
- hypertension
- diabetes mellitus
- age 65-74 yrs
- female sex (AF commoner in males but risker in females)
- vascular disease
Define a transient ischaemic attack (TIA) [1]
a brief episode of neurological dysfunction caused by loss of blood flow (ischaemia) in the brain, spinal cord, or retina, without tissue death (infarction)
What is warfarin? [1]
anticoagulant (blood thinner)
What is warfarin very effective for? [1]
reducing the risk of stroke
What is the problem with warfarin? [1]
it has a narrow therapeutic range - so it needs to be monitored closely
Name the oral anticoagulant drug that acts as thrombin inhibitor [1]
dabigatran
Name the oral anticoagulant drugs that acts as Factor Xa inhibitors [3]
- rivaroxaban
- apixaban
- edoxaban
What are the criteria that a patient with atrial fibrillation needs to meet in order to be referred to OP specialist assesment [5]
- patients who are still symptomatic despite adequate rate control
- young age (<60)
- inadequate rate control despite beta-blocker (or calcium antagnoist) + digoxin
- structural heart disease on echo
- AF and coexisting heart failure (because drugs can affect each other)
What are the 3 options for “rhythm control” for patients with AF? [3]
- direct current cardioversion (for persistent AF)
- antiarrhythmic drugs
- catheter ablation
What are the 3 types of antiarrhythmic drugs (incl. drug names)? [8]
- Class 1 = Na+ channel blockers
- flecainide
- propafenone
- Class 3 = K+ channel blockers (prolong QT interval)
- sotalol
- amiodarone
- multichannel blockers
- dronedarone
What are the limitations with amiodarone? [3]
- has a lot of cardiac side effects
- contains iodine so will affect the thyroid gland
- hyperthyroidism can worsen AF
- so TFTs must be done regularly
Describe how catheter ablation works [3]
- catheter is inserted into the heart and identifies triggers for paroxysmal AF in the pulmonary veins
- once identified, these areas of the myocardium (that are causing the issues) can be either:
- burnt off by a radiofrequency current or
- freezed off (called cryo-ablation)
- more effective in patients with structurally normal hearts or minimal heart disease
If a patient with atrial fibrillation comes in with no or minimal signs for structural heart disease, what are the treatment options? [5]
- dronedarone
- flecainide
- propafenone
- sotalol
- catheter ablation
If a patient with atrial fibrillation comes in with coronary artery disease, significant valvular heart disease or abnormal left ventricular hypertrophy, what are the treatment options? [4]
- dronedarone
- sotalol
- amiodarone
- catheter ablation
If a patient with atrial fibrillation comes in with heart failure, what are the treatment options? [2]
- amiodarone
- catheter ablation
What are the risks associated with catheter ablation? [2]
- risk of bleeding into the pericardium
- risk that if there’s a thrombosis, the catheter might push it out and send it up to brain → stroke
