atrial fibrillation Flashcards
AF is
an arrhythmia cause by disorganised electrical activity in the atria usually leading to rapid and irregular ventricular rate
It is an important cause of morbidity and mortality due to heart failure, stroke and thromboembolism
Different types of AF
- acute onset - started last 24-48 hours
- paroxysmal - recurrent and usually self-terminating - usually lasting < 7 days
- persistent - lasts longer than 48 hours and does not revert spontaneously to sinus rhythm.
- permanent - long standing and not amendable to cardioversion
Cardiac and non cardiac causes of AF
- Cardiac - IHD, hypertension, rheumatic heart disease, cardiomyopathy, pericardial disease
- Non cardiac - thyrotoxicosis, acute infection, pulmonary disease (pneumonia, malignancy, effusion), alcohol XS (acute or chronic) preoperative period.
Common symptoms in AF
those similar to HF
-breathless
-fatigue
pulmonary and peripheral oedema, palpitations, stroke, systemic thromboembolism
Diagnostic tests
- ECG (p-waves and irregular narrow QRS complexes)
- TFTS (rule out thyrotoxicosis)
- LFT’s - if elevated may be alcohol
- CXR - pulmonary?
- Echo (TTE - trans thoracic echo)
- TOE trans oesophageal echo
Aims of AF treatment
- reduce stroke risk
- control related symptoms especially those of HF
- control ventricular rate (rate control)
- cardiovert and maintain sinus rhythm (rhythm control)
drugs care used to encourage prev aims but practitioners should also
- give lifestyle advice
- treat any underlying cause e.g. thyrotoxicosis
- stop ivabradine if this is prescribed in patients with AF
Treatment
Anticoagulation for all
Rate control
- beta blocker (not stool)
- rate limiting CCB (verapamil, diltiazem)
- only consider digoxin mono therapy in sedentary patients presenting with pulmonary oedema or HF.
- if mono therapy doesn’t work then combine
What do we never use together due to the risk of heart block
VERAPAMIL AND BETA BLOCKER
When should we consider rhythm control in AF patients
When there is a reversible cause e.g. acute infection, HF primarily due to new onset AF (less than 48 hours duration)
Pharmacological rhythm control
(<48 hours of symptoms)
- IV felcainide (if no IHD, structural HD or cHD)
- IV amiodorone
- Electrical
if >48 hours then therapeutic anticoagulation with warfarin or NOAC should be given for 3 weeks prior to cardioversion or TOE guided cardioversion to rule out the presence of a thrombus. Continuation of anticoagulation post cardioversion depends on the patients stroke risk but it is usually for 4 weeks.
-Amiodarane may be used for four weeks before elective cardioversion and continued for up to one year to increase the success rate
Standard beta blockers are first line for long term rhythm control.
What do we give in long-term rhythm control if patients are C/I to beta blockers
- flecainide or profafenone if no IHD or CHD
- dronedarone if np LVSD or CHF
We can give amiodarane if LVSD or CHF are present
Pill in the pocket options
- Flecainide - >70kg = 300mg. <70kg = 200mg.
- Propafenone >70kg = 600mg. <70kg = 450mg
Recommended in patients who don’t have CHF or IHD and when the AF occurs they are not haemodynamically unstable. These patients won’t get AF very often. Should be taken if the AF lasts longer than 5 minutes however they should go to hospital if it lasts longer than 6-8 hours.
No more than 1 in 24 hours.
CHA2DS2VASC
Congestive Heart failure = 1 Hypetenstion = 1 Age >75 = 2 Age 65-75=1 Diabetes = 1 Stroke, TIA, thrombus = 2 Vascular disease (pre MI, aortic plaque, peripheral artery disease)= 1 Female = 1
Offer oral anticoagulation in patients with chadsvasc score >2 - taking bleeding risk into account.
HASEBLED
Bleeding risk in AF
Hypertension >160 systolic) = 1 Abnormal liver or renal = 1 Prev stroke = 1 Bleeding (major or preposition) = 1 Lavine INR = 1 Elderly >65 = 1 Drugs (Antiplatelets, NSAIDs) = 1 Alcohol use > 8 weeks per
Score >3 = high risk
