atrial fibrillation Flashcards
what form occurs in younger patients
paroxysmal
causes
conditions resulting in:
- raised atrial pressure
- increased atrial muscle mass
- atrial fibrosis
- inflammation
- infiltration of atrium
classic causes
- alcohol
- thyrotoxicosis
- hypertension
- heart failure
- hyperthyroidism
what test is mandatory in patients with AF
thyroid function test
what chromosomes are associated with familiar atrial fibrillation
10
6
5
4
what is atrial fibrillation maintained by
continuous rapid activation of atria by multiple meandering re-entry wavelets.
symptoms
- palpitations
- dyspnoea
- chest pain
- decrease exercise capacity
- irregular irregular pulse
ECG findings
oscillations of baseline
- no p waves
- rapid QRS rhythm that is irregular
acute management
- rate control
- cardioversion
how is cardioversion done
electrically by DC shock
or
medically by intravenous infusion
how is most conversion to sinus rhythm done
electrical DC cardioversion
how to minimise risk of thromboembolism associated with cardioversion
anti-coagulate with warfarin or dabigatran
what is done if patient has to have urgent cardioversion not prevent atrial thrombus
transoesophageal echocardiography is used
what are the two long term management
- rate control
- rhythm control
who is rhythm control mostly for
younger, symptomatic and physically active
what are patients with no significant heart disease treated with
class Ia, Ic or III anti arrhythmic drug
don’t use amiodarone until other drug failed
what is given to patients who also have heart failure or LVH
amiodarone
what is given to patients with coronary artery disease
sotalol or amiodarone
who is rate control given to
- permanent form of arrhythmia associated with symptoms
- older than 65 with recurrent atrial tachyarrhythmias
- have failed cardioversion
how is rate control achieved
combination of:
- digoxin
- beta blockers
- rate limiting calcium channel (verapamil, diltiazem)
when is digoxin monotherapy sufficient
elderly, non-ambualnt patients
how to assess adequacy of rate control
ECG - elders
ambulatory 24-monitoring and exercise stress - younger patients
when is anticoagulation indicated
patients with AF related to rheumatic mitral stenosis
or
presence of mechanical prosthetic valve
what scoring system is used in patients with non-valvular atrial fibrillation to determine need for anticoagulation
CHA2 DS2 VASc
Sc = sex category (female)
using CHA2 DS2 VASc when is anticoagulation given
1 = anticoagulant or aspirin
2+ = oral anticoagulant
what anticoagulant is given if patient has valvular atrial fibrillation
vitamin K antagonist
what anticoagulant is given when patient <65 year and lone AF
no antithrombotic therapy
what anticoagulant therapy is given for a CHA2 DS2 VASc of 0
no antithrombotic therapy
what anticoagulant is given for a CHA2 DS2 VASc of >1
oral anticoagulant therapy
assess bleeding risk (HAS-BLED score)
what is given when anticoagulation is required
warfarin or NOAC
NOAC = dabigatran and rivaroxaban
how to NOAC work
block a single step in coagulation cascade
