Cardiology 10 - Atrial Fibrillation Flashcards
define atrial fibrillation
disorganised electrical activity leading to uncoordinated and irregular atrial contraction
4 consequences of AF
irregularly irregular heart beat
tachycardia
heart failure due to poor diastolic filling
risk of stroke
4 possible presenting symptoms of AF
palpitations shortness of breath syncope (dizzy or fainting) assoc conditions (stroke, sepsis, thyrotox)
2 differentials for irregularly irregular pulse
atrial fibrillation
ventricular ectopics
4 features of AF on an ECG
absent p waves
irregularly irregular rhythm
narrow QRS complexes
tachycardia
define valvular AF
AF found in patients with severe mitral stenosis or mechanical heart valve (which likely caused it)
5 most common causes of AF
sepsis mitral valve pathology ischaemic heart disease thyrotoxicosis hypertension
3 aspects of treating AF
rate control
rhythm control
anticoagulation
4 contraindications for rate control in AF (i.e. indications for first line rhythm control)
- reversible cause
- new onset <48 hrs AF
- AF is causing heart fail
- symptomatic on rate control
give options 1,2,3 for rate control in AF
- beta blocker (e.g. atenolol 50-100mg OD)
- calcium-channel blocker (e.g. diltiazem)
- digoxin (if sedentary - monitor as toxicity risk)
4 options for rhythm control in AF
- electrical or medical cardioversion
- beta blockers (1st line)
- dronedarone (maintenance therapy after cardioversion)
- amiodarone (if LV dysfunction)
define choice between immediate vs delayed cardioverison
immediate = if AF <48 hours old or they are haemodynamically unstable
delayed = if opposite is true
what is needed pre delayed cardioversion?
anticoagulation for 3 weeks prior
describe 2 drug options for cardioversion and the electrical option
flecanide 1st line
amiodarone if structural heart disease
for DC cardioversion, sedate or anaesthetise + timed shocks
define paroxysmal AF and its treatment
intermittent episodes lasting less than 48 hours
anticoagulate based on Chadsvasc
offer ‘pill in pocket’ therapy if infrequent and no structural heart disease
flecanide is used
when should flecanide be avoided?
in atrial flutter as can cuase 1:1 AV conduction and thus v fast heart rate
where does blood particular pool in AF?
atrial appendage
define the risk of stroke in AF
roughly 5% a year, reduced to 2% with anticoagulation
this gives them a 3% risk of serious bleed a year
define: warfarin INR which drugs/foods to avoid alongside reversing warfarin
vitamin K antagonist prolonging prothrombin time
INR = PT patient vs normal
target 2-3 usually
avoid cytochrome P450 affectors (e.g. especially Abx)
beware high vit K veg + cranberry juice / alcohol
half life 1-3 days, reverse with Vit K
NOACs x3
why
apixiban, dabigitran BD
rivaroxaban OD
no monitoring, no major interactions, slightly better at stroke risk, slightly better with bleeds
define the scoring of when you offer anticoagulation in Chadsvasc
definite if 2+
consider if 1
none if 0
give the components of the CHA2DS2VASc score
Congestive heart failure Hypertension Age >75 (2 = scores 2) Diabetes Stroke/TIA (2= scores 2) Vascular disease Age 65-74 Sex female
give the components of the HAS-BLED score
use an online calculator - provides yearly bleeding risk on anticoag
HTN Abnormal renal /liver Stroke Bleeding Labile INRs Elderly Drugs or alcohol
