Atrial Fibrillation Flashcards
Who gets AF?
Most common arrhythmia - 1 million people in the UK
More common with age and in men
More common in those with HTN, atherosclerosis, obese, drinkers
What causes AF?
Cardiac - valvular disease, coronary artery disease, MI, congenital conduction issues, previous heart surgery; HTN
Metabolic -hyperthyroidism, Infections ie pneumonia, Electrolyte imbalance, Stimulants - medication, caffeine, tobacco, alcohol
Lung disease, Sleep apnoea
What is the pathophysiology of AF?
Random/non-coordinated contractions of atria due to abnormal electrical discharge
How might AF present?
Asymptomatic Palpitations Shortness of breath dizziness or syncope Chest pain
How do you investigate AF?
Pulse - irregularly irregular, tachy or brady
ECG - will be able to tell you exactly what’s going wrong, but maybe not why; 24hr monitoring; use lead which shows P wave clearly i.e. II or V1 to identify conduction issues
Bloods - FBC, U+E (esp. K), glucose, Ca, Mg, TSH, coagulation (pre anti-coag Tx) etc
Echo - structural heart changes
Vagal manoeuvres or adenosine (adenosine causes temporary AV block → slows ventricles to show underlying arrhythmia and converting a junctional tachycardia to sinus rhythm)
What does AF look like on an ECG?
No P waves, just an irregular baseline; irregular but normal shaped QRS 75-190bpm; V1 looks like atrial flutter; normal T waves
How do you assess stroke risk?
AF (paroxysmal and persistent) increases stroke risk x6
CHA2DS2-VASc
i) CCF (LF or both failure) +1
ii) HTN (resting >140/>90 on 2 occasions or on BP management +1
iii) Age >75 +2
iv) Diabetes +1
v) Stroke/TIA/thrombo-embolism +2
vi) Vascular disease (MI/angina/CABG/PCI/claudication/A or VTE/thoracic, abdominal or lower vascular surgery) +1
vii) Age 65-74 +1
viii) Sex category (Female) +1
Total = 9
0 = low risk, anticoag not indicated/preferred
1 = low-med risk, consider anticoag (e.g. apixaban)
2+ = moderate-high risk, anticoag indicated
(Need to complete a HASBLED score before starting)
finish these cards using
http://www.uhnm.nhs.uk/STAC/Documents/160614%20AF%20NICE%20guidelines%202014.pdf
When is hospital admission indicated in AF?
Pulse >150 and or systolic <90
LoC, severe dizziness, ongoing chest pain, increasing breathlessness
Complication of AF e.g. TIA, stroke, acute heart failure
When should AF be referred to a cardiologist?
Person <50yrs
Paroxysmal AF suspected
Uncertainty around rate or rhythm control
Drug treatments used in primary care are contraindicated or have failed to control symptoms
Person is found to have valvular heart disease or L systolic dysfunction
WPW or QTc prolongation suspected
What are the steps of management for AF?
Rate control = first line
- Betablocker e.g. atenolol OR
- Rate limiting CaB e.g. diltiazem, verapamil OR
- Digoxin (only if they are sedentary)
If monotherapy does not control, combination of any two of:
- Betablocker, diltiazem, digoxin
Amiodarone is NOT used for long term rate control
When do we consider rhythm control and what does this consist of?
For patients with AF whose symptoms persist after rate control strategies have been tried and proven unsuccessful
Elective cardioversion:
- For patients with AF >48hrs = electrical
- Consider amiodarone therapy starting 4wks prior and continuing for 12 months after electrical cardioversion to maintain SR
- Must be anticoagulated for minimum of 3wks prior
Long term rhythm control:
- Betablocker = first line if possible
- Dronedarone = if unsuccessful and patient has HTN (on 2x drugs), DM, TIA/CVA Hx, LAH, >70yrs
- Amiodarone = if LV impairment or CCF
1c anti-arrhythmic drugs e.g. flecainide or propafenone should NOT be given to people with structural heart disease
What is an alternative strategy for managing paroxysmal AF?
‘Pill in the pocket’
- For patients with infrequent paroxysms, or known triggers (e.g. alcohol, caffeine), with few symptoms, and who have no LV dysfunction or CHD, and have a systolic >100 and resting HR >70
Can be given betablockers to take ‘as and when’
What surgery might be indicated in AF?
Pacing and or ablation:
- Patient may be fine when paced, or fine after catheter ablation, or may require both
How do we manage acute symptomatic AF?
Emergency electrical cardioversion for patients with AF leading to haemodynamic instability
- Rate OR rhythm control if <48hrs
- Rate control if >48hrs/uncertain
Rhythm control
= flecainide OR amiodarone if no evidence of structural or coronary heart disease
= amiodarone if evidence of structural heart disease
