Atrial Fibrillation Flashcards
treatment to prevent thromboembolic events in AFib
DOAC
apixaban (eliquis), rivaroxiban, dabigatran
when is warfarin used
for patients with rheumatic mitral stenosis or mechanical heart valve
these patients have a particularly increased risk of thromboembolic events
use warfarin oral daily with dose adjusted to the target INR
why are DOACs usually preferred
DOACs have comparable efficacy with lower bleeding risks for all other Afib patients including those with mitral regurgitation and biprosthetic heart valves
for a patient with AFib and an indication for DAPT
triple antithrombotic therapy eg. oral anticoagulant, aspirin and a P2Y12 inhibitor
what factors does the management strategy depend on
the patients haemodynamic state
duration of the episode
the patient’s thromboembolic risk
whether procedural sedation and electrical cardioversion are available
patient preference
2 methods for initial arrythmia management
rhythm control: electrical or pharmacological cardioversion
rate control: controlling ventricular rate
atrial fibrillation lasting <48 hours
rate control or rhythm control
if rhythm control is used, use anticoagulant therapy at the time of cardioversion and continue long term
atrial fibrillation lasting >48 hours
If atrial fibrillation has lasted longer than 48 hours, or if the duration of atrial fibrillation is unknown, do not perform acute cardioversion unless left atrial thrombus has been excluded, or the patient has had therapeutic anticoagulation for a minimum of 3 weeks. If atrial thrombus has not been excluded, or the patient is not anticoagulated, rate control is the preferred initial treatment
how do you exclude left atrial thrombus
For patients who are not anticoagulated, transoesophageal echocardiography (TOE) may be considered to exclude left atrial thrombus and allow for early cardioversion. For these patients, anticoagulant therapy should be started at the time of cardioversion and continued for a minimum of 4 weeks after cardioversion.
what kind of patients stand to benefit from cardioversion/rhythm control
have recently been diagnosed with AF
remain symptomatic despite adequate rate control therapy
have a reduced left ventricular ejection fraction that might be due to atrial fibrrillation
electrical cardioversion
synchronised direct current to restore sinus rhythm
requires procedural sedation
pretreatment with antiarrythmetic drug can improve success rates
pharmacological cardioversion
restores sinus rhythm for 50% of patients
does not require procedure sedation
long term rhythm control
intended to reduce symtoms
modest long term efficacy
use catheter ablation or
sotolol or flecanide or amiodarone
long term rate control
aim to prevent haemodynamic deterioration
use beta blockers first line eg. atenolol, metoprolol
CCBs 2nd line eg. diltiazem, verapamil
or
digoxin 3rd line
amiodarone 4th line
post operative AF
common post operative complication, particulalry after cardiac surgery
usually revert within 24 hours
