II. Precautions
- Exercise caution in cardioversion if Electrolyte disturbance (e.g. Hypokalemia, Digoxin Toxicity)
- Patients with Atrial Fibrillation are unreliable in judging Atrial Fibrillation duration (i.e. longer or shorter than 48 hours)
- Less than 70% of patients can actively predict when they are in paroxysmal Atrial Fibrillation
- Patients with Atrial Fibrillation are asymptomatic as often as 40-60% of the time
- Non-anticoagulated patients may form atrial thrombus at any time (even within 48 hours) and may not be detected by TEE
- Non-anticoagulated emergency department cardioversion-related Thromboembolism rate: <7% (mean 1.5%)
- Left atrial thrombus is present in 14% of non-anticoagulated patients with Atrial Fibrillation <48 hours (by TEE)
- Left atrial thrombus is present in 27% of non-anticoagulated patients with chronic Atrial Fibrillation
- Left atrial thrombus may be present as early as 12 hours after Atrial Fibrillation onset
- Stoddard (1995) J Am Coll Cardiol 25(2): 452-9 [PubMed]
- Nuotio (2014) JAMA 312(6): 647-9 +PMID:25117135 [PubMed]
- Thromboembolism occurs in 6% of cardioversion patients who had normal TEE prior to cardioversion
- Postulated acute Clot Formation from cardioversion-induced atrial stunning (persists for days to weeks)
- Fatkin (1994) J Am Coll Cardiol 23(2): 307-16 [PubMed]
- One study suggested Atrial Fibrillation duration for safe cardioversion might be as short as 12 hours (not 48 hours)
- However, electrical Cardioversion in Atrial Fibrillation <48 hours appears safe with a low overall Thromboembolism risk
- Cardioversion may not offer initial benefit for hemodynamically stable patients
- Many patients feel un-well while in Atrial Fibrillation, and cardioversion appears as a "quick fix"
- Spontaneous conversion to sinus rhythm occurs in 66% of patients within 24 hours and 80% within 48 hours
- Early cardioversion appears to offer no benefit over delayed cardioversion at 4 weeks
-
Left Ventricular Dysfunction and valvular defect patients may have even less benefit AND Thromboembolism risk
- Theoretical benefit of potentially increased atrial kick may not be beneficial in practice
- Atrial kick (10-15% of Cardiac Output) does not return for days to weeks after cardioversion (due to atrial stunning)
- Successful cardioversion rates are significantly worse in Left Ventricular Dysfunction
- Left Ventricular Dysfunction significantly increases the risk of Thromboembolism
- Risk factors for stroke after cardioversion
- Unknown time of Atrial Fibrillation onset
- History of Transient Ischemic Attack or stroke in the last 6 months
- Mechanical Heart Valve
- Rheumatic Heart Disease
- Caveat
- Emergent cardioversion is indicated in a hemodynamically Unstable Patient
- See Atrial Fibrillation Synchronized Cardioversion
III. Approach: Atrial Fibrillation Cardioversion if duration <48 hours (acute Atrial Fibrillation)
- See Atrial Fibrillation Cardioversion regarding precautions
- See precautions above (as Thromboembolism risk still exists despite short duration of Atrial Fibrillation)
- Consider Heparin while considering cardioversion
- Consider early Atrial Fibrillation Cardioversion
- Many patients prefer this when presenting with recurrence of Atrial Fibrillation to the Emergency Department
- Atrial Fibrillation is uncomfortable (Dyspnea, Light Headedness) and rate control medications have adverse effects
- Discharge after emergency department cardioversion is safe with a low complication rate
- Cardioversion options
- Atrial Fibrillation Synchronized Cardioversion (preferred, most effective, safest option)
- May be preceded by chemical cardioversion attempt (e.g. Ottawa protocol as below)
- Results in earlier discharge compared with chemical cardioversion for CHADS 0 to 1
- Atrial Fibrillation Chemical Cardioversion
- Atrial Fibrillation Synchronized Cardioversion (preferred, most effective, safest option)
- Nonstandard Cardioversion options
- Endurance athletes with paroxysmal Atrial Fibrillation (stable patients)
- Self-cardioversion with aerobic Exercise (ventricular rates above a. fib rate) has been documented
- Paroxysmal Atrial Fibrillation is at increased risk in endurance athletes
- More common in males, and athletes who started at a young age
- Stergiou (2018) Curr Treat Options Cardiovasc Med 20(12):98 +PMID: 30367267 [PubMed]
- Endurance athletes with paroxysmal Atrial Fibrillation (stable patients)
- Ottawa Aggressive Protocol
- First: Procainamide 1 g over 1 hour
- Risk of Hypotension and QRS Widening
- Next: Atrial Fibrillation Synchronized Cardioversion (if no effect with Procainamide)
- Efficacy
- Sinus rhythm conversion rate at time of ED discharge: 90%
- ED discharge rate: 97%
- Relapse rate: 9% at 7 days
- Safety
- Patients must be stable
- No Thromboembolism
- References
- First: Procainamide 1 g over 1 hour
IV. Approach: Atrial Fibrillation Protocol for cardioversion if duration more than 48 hours
- Warfarin or DOAC (or other approved Anticoagulant) for 3 weeks before cardioversion
- Consider Atrial Fibrillation Cardioversion
- Continue Warfarin or DOAC (or other approved Anticoagulant) for 4 weeks after cardioversion
- Early cardioversion acceptable if cleared with TEE first
V. Management: Disposition
- See Atrial Fibrillation Acute Management for disposition management
- See Atrial Fibrillation Anticoagulation
- Expert opinion recommends Atrial Fibrillation Anticoagulation for 3 weeks after electrical cardioversion
- Reduces risk of Thromboembolism formation from stunned Myocardium
VI. References
- Casaletto (2014) Crit Dec Emerg Med 28(4): 10-19
- Orman and Berg in Herbert (2016) EM:Rap 16(2): 6-10
- Stiell (2011) Canadian J Cardiol 27(1): 38-46 [PubMed]
- Wann (2011) Circulation 123(1): 104-23 [PubMed]
- King (2002) Am Fam Physician 66(2):249-56 [PubMed]
- Gutierrez (2011) Am Fam Physician 83(1): 61-8 [PubMed]
- Falk (2001) N Engl J Med 344:1067-78 [PubMed]
- Li (1998) Emerg Med Clin North Am 16:389-403 [PubMed]
- King (2002) Am Fam Physician 66:249-56 [PubMed]
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Related Studies
Definition (CHV) | rapid tremor and shake of upper chambers of the heart |
Definition (CHV) | rapid tremor and shake of upper chambers of the heart |
Definition (CHV) | rapid tremor and shake of upper chambers of the heart |
Definition (CHV) | rapid tremor and shake of upper chambers of the heart |
Definition (CHV) | rapid tremor and shake of upper chambers of the heart |
Definition (CHV) | rapid tremor and shake of upper chambers of the heart |
Definition (MEDLINEPLUS) |
An arrhythmia is a problem with the speed or rhythm of the heartbeat. Atrial fibrillation (AF) is the most common type of arrhythmia. The cause is a disorder in the heart's electrical system. Often, people who have AF may not even feel symptoms. But you may feel
AF can lead to an increased risk of stroke. In many patients, it can also cause chest pain, heart attack, or heart failure. Doctors diagnose AF using family and medical history, a physical exam, and a test called an electrocardiogram (EKG), which looks at the electrical waves your heart makes. Treatments include medicines and procedures to restore normal rhythm. NIH: National Heart, Lung, and Blood Institute |
Definition (NCI_CTCAE) | A disorder characterized by a dysrhythmia without discernible P waves and an irregular ventricular response due to multiple reentry circuits. The rhythm disturbance originates above the ventricles. |
Definition (NCI_FDA) | An arrhythmia in which minute areas of the atrial myocardium are in various uncoordinated stages of depolarization and repolarization; instead of intermittently contracting, the atria quiver continuously in a chaotic pattern, causing a totally irregular, often rapid ventricular rate. |
Definition (NCI) | A disorder characterized by an electrocardiographic finding of a supraventricular arrhythmia characterized by the replacement of consistent P waves by rapid oscillations or fibrillatory waves that vary in size, shape and timing and are accompanied by an irregular ventricular response. (CDISC) |
Definition (CSP) | disorder of cardiac rhythm characterized by rapid, irregular atrial impulses and ineffective atrial contractions. |
Definition (MSH) | Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (HEART ATRIA). In such case, blood cannot be effectively pumped into the lower chambers of the heart (HEART VENTRICLES). It is caused by abnormal impulse generation. |
Concepts | Pathologic Function (T046) |
MSH | D001281 |
ICD9 | 427.31 |
SnomedCT | 155364009, 266306001, 49436004 |
LNC | LA17084-7 |
English | Atrial Fibrillations, Auricular Fibrillation, Auricular Fibrillations, Fibrillations, Atrial, Fibrillations, Auricular, FIBRILLATION ATRIAL, AURICULAR FIBRILLATION, Auricular fibrillation, Fibrillation, Atrial, Fibrillation, Auricular, AF, atrial fibrillation, atrial fibrillation (diagnosis), Afib, AFib, Fibrillation atrial, Atrial Fibrillation [Disease/Finding], Fibrillation;atrial, afib, atrial fibrillation (AF), auricular fibrillations, atrial fibrillations, Familial Atrial Fibrillation, Fibrillation - atrial, ATRIAL FIBRILLATION, Atrial fibrillation, AF - Atrial fibrillation, Atrial fibrillation (disorder), atrium; fibrillation, auricular; fibrillation, fibrillation; atrial or auricular, Atrial Fibrillation, auricular fibrillation |
French | FIBRILLATION AURICULAIRE, FA, AFib, Fibrillation auriculaire, Fibrillation atriale |
German | VORHOFFLIMMERN, AF, Afib, Flimmern Vorhof, Herzohrflimmern, HERZVORHOFFLIMMERN, Vorhofflimmern, Aurikuläres Flimmern |
Portuguese | FIBRILACAO AURICULAR, FA, FIBRILHACAO AURICULAR, Fibrilhação auricular, Fibrilação Atrial, Fibrilação Auricular |
Spanish | FIBRILACION AURICULAR, FA, Fibrilación atrial, AURICULAR, FIBRILACION, fibrilación auricular (trastorno), fibrilación auricular, Fibrilación auricular, Fibrilación Atrial, Fibrilación Auricular |
Dutch | AFib, AF, atriumfibrillatie, hartoorfibrilleren, atrium; fibrilleren, auriculair; fibrilleren, fibrilleren; atrium of auriculair, atriale fibrillatie, Atriumfibrillatie, Boezemfibrillatie, Fibrillatie, atrium-, Fibrillatie, boezem-, Fibrilleren, boezem- |
Swedish | Förmaksflimmer |
Japanese | シンボウサイドウ, 心房細動, 心房性細動 |
Finnish | Eteisvärinä |
Russian | USHKA PREDSERDIIA FIBRILLIATSIIA, PREDSERDII FIBRILLIATSIIA, ПРЕДСЕРДИЙ ФИБРИЛЛЯЦИЯ, УШКА ПРЕДСЕРДИЯ ФИБРИЛЛЯЦИЯ |
Czech | Fibrilace ouška, Fibrilace síní, fibrilace síní, síňová fibrilace, FiS |
Italian | Fibrillazione auricolare, Fibrillazione atriale |
Croatian | ATRIJ, FIBRILACIJA |
Polish | Migotanie przedsionków |
Hungarian | AFib, Fibrillatio atrialis, Pitvarfibrillatio |
Norwegian | Forkammerflimmer, Hjerteflimmer, Artrieflimmer |