See: [[Cardioversion]], [[Atrial Flutter]] [Atrial fibrillation mgmt Dunn](x-devonthink-item://A1A18198-7B1E-4E86-A927-375D9A7134B7), [Dunn - Assessment of atrial fibrillation or flutter](x-devonthink-item://C4EAFAD2-01B6-4A0B-9494-2CCD06635560), [Rosen - Atrial Fibrillation](x-devonthink-item://F2F0190B-D639-41DF-9A27-931676B7B51A?page=16) #incomplete > [!key points] > - Atrial fibrillation and [[Atrial Flutter]] are both caused by macro reentry circuits occurring within the atrial myocardium. In **atrial fibrillation** the reentering impulses cycles around multiple circuits, resulting in irregular fibrillory waves. in flutter, the re-entering impulse cycles around a single circuit, resulting in regular "sawtooth" flutter waves > - **non-valvular AF** refers to AF in the absence of mitral stenosis (mod or severe) or mechanical heart valve ## Treatment table | Strategy | description | indications | disadvantages | | ---------------------------- | ---------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------ | | "watch and wait" | - observe await spont reversion<br>- +/- correct ↓ K and MgSO4 | - EtOH intoxication<br>- stimulant-related AF<br>- other secondary AF<br>- ↑ risk from other strategies | - success ~50% in 24 hours<br>- longer time in ED<br>- may not have easy follow up for delayed cardioversion | | flecainide | 2mg/kg IV (to 150mg) or 200-300mg pd | - structurally normal heart<br>- normal QTc<br>- EF > 40% | - proarrhythmic potential<br>- takes an hour to work <br> | | electrical [[Cardioversion]] | synchronised DCR 100J then 200J up to 3 shocks | - unstable pt<br>- APO<br>- myocardial ischaemia<br>- within 48 hours (ideally < 12) | - sedation risks<br>- can precipitate VF if not synchronised | | [[Amiodarone]] | 4-5 mg/kg IV over 30 min | older pts<br>secondary AF with ↑ HR causing haemodynamic compromise<br>- structurally abnormal heart<br>- high risk sedation<br>- mild/mod AF<br>- rate control is acceptable if reversion fails | - hypotension<br>- pro-arrhythmia<br>- slower onset of action<br>- 40% success at 8 hrs | | rate control | - metoprolol 25 - 50 mg po<br>5-15 mg IV)<br><br>- digoxin 500mcg loading then 250mcg Q 4-6 hr total 1.5mg | - older age<br>- sedentary<br>- no cardiac failure<br>- unlikely to stay in sinus rhythm<br>- contraindications to anti-arrhythmic drugs<br>- mitral stenosis | unstable pt needing rhythm control | > note: diltiazem less negative ionotropy than verapamil for rate control, but we don't have IV diltiazem in australia ## Valvular vs non-valvular AF CHADS2 VASC for non-valvular AF - **non-valvular AF** → consider oral anticoagulation if score 1, give *DOAC* if ≥ 2 - **valvular AF** → *warfarin* recommended (mod or severe mitral stenosis or mechanical heart valve) ## Scores ![[Pasted image 20241022225543.png]] ![[Pasted image 20241022225552.png|HAS-BLED ≥ 3 indicates ↑ risk and need for caution]] ## Rate vs rhythm control evidence - [Effect of non-invasive rhythm control on outcomes in patients with first diagnosed atrial fibrillation presenting to an emergency department. 2025](bookends://sonnysoftware.com/ref/DL/283606) - retrospective registry data, needs prospective validation