Complications:
- emboli
- cardiac failure
- aggravation of IHD, etc.
Options for Rapid control of ventricular rate:
- digoxin: 0.5 mg IVI q4h max 1.5 mg
- 0.0625 – 0.5 mg daily PO maintenance
- verapamil: 1 mg / min. → 15 mg / min. (max); watch BP
- 40 – 160 mg q8h PO maintenance
- + quinidine slow release 250 – 750 mg q12h PO for 24 hours
- synchronised DC cardioversion
- analgesia / sedation
- start 50 – 100 J
- If sinus rhythm achieved, prevent recurrence with
- quinidine + digoxin
- low dose amiodarone
- His-bundle ablation + PPM
- If QRS ≥ 0.12 sec
- flecainide or sotalol or amiodarone, OR
- early DC cardioversion (symptomatic / hypotensive)
Causes of atrial fibrillation:
- Ischaemic Heart Disease
- Mitral valve disease
- thyrotoxicosis
- hypertensive heart disease
- SSS
- PE
- myocarditis / ethanolic heart disease
- paroxysmal – fever / hypoxia / hypercapnoea
- lone fibrillator
Treatment:
- treat the cause, then 80% will DC cardiovert
- definitive treatment: anti-arrhythmic agent (Vaughan-Williams (VW) classification)
- intravenous Ia: moderate blockage of fast sodium channels
- quinidine, procainamide, disopyramide
- Ic: marked degree of sodium blockage and no effect on QT; reasonable for ongoing management in patients without structural heart disease or ischemic heart disease
- flecainide, propafenone
- III: potassium channel blockers decrease potassium efflux out of the cell and prolong the QTc interval
- Amiodarone, Dronedarone, Dofetilide, Sotalol, Ibutilide
- ± DC cardiovert
- intravenous Ia: moderate blockage of fast sodium channels
- ± anticoagulation
Management of atrial fibrillation breakthrough with rapid ventricular response: AAD: antiarrhythmic drug; BB: beta blocker; CCB: calcium channel blocker; CHF: chronic heart failure; DCCV: Direct current cardioversion; TEE: Trans-esophageal echocardiogram and LAA : Left atrial appendage. Full anticoagulation: either with 4 consecutive weeks of warfarin therapy with weekly therapeutic INR (2-3) or four weeks of the novel oral anticoagulants (NOACs) without any interruption even for one dose. Ibutilide is an intravenous AAD, which is usually used for pharmacologic cardioversion in normal heart structure and normal QT interval.¹
Common mistakes²
Anticoagulation
Although the risk of thromboembolism may indeed be higher in patients with persistent AF, thromboembolic risk may be substantial even in patients with paroxysmal AF. Therefore decisions regarding anticoagulation should be predominantly based on the presence or absence of well established risk factors for thromboembolism, including previous stroke or transient ischaemic attack, valvular or other structural heart disease, hypertension, diabetes, age more than 65 years, and echocardiographic parameters such as left ventricular function and left atrial size, rather than on the temporal pattern of the disease.
Rate control
β Blockers or calcium antagonists are more effective than digoxin alone.
Rhythm control
Digoxin has no effect on the likelihood of cardioversion, whereas class I antiarrhythmic drugs or amiodarone are often effective.
- Amin A, Houmsse A, Ishola A, Tyler J, Houmsse M. The current approach of atrial fibrillation management. Avicenna J Med. 2016 Jan-Mar;6(1):8-16. doi: 10.4103/2231-0770.173580. PMID: 26955600; PMCID: PMC4759971.
- V, Schilling RJ. Atrial fibrillation: classification, pathophysiology, mechanisms and drug treatment. Heart. 2003 Aug;89(8):939-43. doi: 10.1136/heart.89.8.939. PMID: 12860883; PMCID: PMC1767799.
- Gelder, I., M. Rienstra, H. Crijns and B. Olshansky. “Rate control in atrial fibrillation.” The Lancet 388 (2016): 818-828.
- Shettigar UR. Management of rapid ventricular rate in acute atrial fibrillation. Int J Clin Pharmacol Ther. 1994 May;32(5):240-5. PMID: 7921518.
