Atrial Fibrillation =================== þ Who to convert in the ED? - is a TEE needed? Still some risk of atrial stunning > clot, but if no clot, can decrease the length of anticoagulation. - 48 hour rule for blind conversion? Only if low risk for complications. - Low risk: Young (< 575, no CAD, no DM or HTN, no suspicion for MI or PE, no prior history of CVA or CNS bleed; or, low CHAD score - CHAD score Aka: CHADS Score, CHADS2 1. Indication 1. Assess Risk of stroke with Atrial Fibrillation 2. Criteria (mneumonic: CHADS) 1. Congestive Heart Failure (1 point) 1. Relative risk of Stroke or TIA: 1.4 2. Hypertension (1 point) 1. Relative risk of Stroke or TIA: 1.6 3. Age over 75 years (1 point) 1. Relative risk of Stroke or TIA: 1.4 4. Diabetes Mellitus (1 point) 1. Relative risk of Stroke or TIA: 1.7 5. Stroke or TIA history (2 points) 1. Mitral Stenosis or prosthetic heart valve carry similar risk and also indicate Warfarin 2. Relative risk of Stroke or TIA: 2.5 3. Interpretation 1. CHADS Score >2 (CVA risk >5% per year): Warfarin with goal INR 2.0 to 3.0 2. CHADS Score >1 (CVA risk >4% per year): Warfarin or Aspirin 3. CHADS Score 0: Aspirin 81 to 325 mg daily 4. References 1. Gage (2004) Circulation 110:2287 - TEE shows more people with clots in the heart than we thought. Some say we should not convert any of these people, that clots are too likely. - Unstable patients. - If already anticoagulated. - Informed consent in the ED? - 50% will convert in 1-2 days. - choose: procan, quinidine, flecanide, propafenone, ibutilide, amiodarone, sotalal, electricity, nothing: electricity wins. - AFFIRM trial showed no difference between rate control and conversion. - Prehospital? stable patient: NO Verapamil! - known accessory pathway: NO Verapamil! þ (Reuters Health) - Controlling heart rate - not cardiac rhythm - is the recommended strategy for most patients with atrial fibrillation, according to new guidelines for patients with new-onset disease issued Monday by the American Academy of Family Physicians and the American College of Physicians (ACP). The guidelines, which are reported in the December 16th issue of the Annals of Internal Medicine, stem from a review of randomized, controlled trials that looked at treatment of the rhythm disturbance. Combined with a previous systematic review, more than 200 studies were eligible for analysis. Based on the review, Dr. Vincenza Snow, from the ACP in Philadelphia, and colleagues came up with six recommendations for managing newly detected atrial fibrillation: --The preferred strategy for most patients is rate control plus chronic anticoagulation. Rhythm control does not provide better outcomes than rate control and, in some patient subgroups, it may produce worse outcomes. --Adjusted-dose warfarin should be given to patients unless they have a very low risk of stroke or a contraindication to such therapy. --Suitable rate control drugs include atenolol, metoprolol, diltiazem, and verapamil. Because digoxin is not effective for rate control during exercise, it should only be used as a second-line therapy. --Direct-current cardioversion and pharmacologic conversion are both appropriate choices for patients who elect to undergo acute cardioversion in order to achieve sinus rhythm. --Transesophageal echocardiography with prior anticoagulation followed by acute cardioversion with anticoagulation or delayed conversion with pre- and post-anticoagulation are suitable choices for patients undergoing cardioversion. --Once sinus rhythm is achieved, rhythm maintenance therapy is not indicated as the risks usually outweigh the benefits. However, such therapy may be warranted for patients whose quality of life was severely impaired by their rhythm disturbance. Copyright 2003 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world. þ Harvey Louzon's Summary of Issues for Atrial Fibrillation þ Digoxin vs. other drugs for atrial fibrillation: þ To slow ventricular rate in atrial fibrillation: - digoxin - verapamil - esmolol (but none of above convert back to NSR) - IV diltiazem is choice to slow rate if CHF þ To convert from atrial fibrillation to NSR - Other than the need for anticoagulation a good rationale for early conversion is that the single most important predictor of *successful* conversion is one that is done promptly. [Arnar DO, Danielsen R. Factors predicting maintenance of sinus rhythm after direct current cardioversion of atrial fibrillation and flutter: a reanalysis with recently acquired data. Cardiology 1996 May-Jun; 87(3):181-8.] Abstract: - use cardioversion or IV procainamide. - it is standard to block the AV node before giving IV procainamide (to prevent paradoxical speeding up) but it has been used successfully by itself: [Fulham MJ, Cookson WO, Sher M. Procainamide infusion and acute atrial fibrillation. Anaesth Intensive Care 1984 May;12(2):121-4.] Abstract: þ To keep those with history of atrial fibrillation in NSR - use Quinidine. But increases mortality, it looks like: þ Anticoagulation in Atrial Fibrillation: - [Mugge A. Anticoagulation in patients with atrial fibrillation. Herz 1996 Feb;21(1):28-36.] þ Magnesium for Atrial Fibrillation