Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine by Marc Sabatine Page A

(rheumatic MV disease, prosthetic valve or valve repair) vs. nonvalvular • Lone AF = age <60 y and w/o clinical or echo evidence of cardiac disease (including HTN) Epidemiology and etiologies ( Annals 2008;149:ITC5-2)
• 1–2% of pop. has AF (8% of elderly); lifetime risk 25%; mean age at presentation ~75 y • Acute (up to 50% w/o identifiable cause)
Cardiac : HF, myo/pericarditis, ischemia/MI, hypertensive crisis, cardiac surgery
Pulmonary : acute pulmonary disease or hypoxia (eg, COPD flare, PNA), PE, OSA
Metabolic : high catecholamine states (stress, infection, postop, pheo), thyrotoxicosis
Drugs : alcohol (“holiday heart”), cocaine, amphetamines, theophylline, caffeine
Neurogenic : subarachnoid hemorrhage, ischemic stroke
• Chronic: ↑ age, HTN, ischemia, valve dis. (MV, TV, AoV), CMP, hyperthyroidism, obesity Evaluation
• H&P, ECG, CXR, TTE (LA size, thrombus, valves, LV fxn, pericardium), K, Mg, FOBT before anticoag, TFTs; r/o MI not necessary unless other ischemic sx
Figure 1-5  Approach to acute AF

(Adapted from NEJM 2004;351:2408; JACC 2006;48:e149)

    Strategies for recurrent AF ( Circ 2011;123:104; Lancet 2012;379:648)
• Rate control : goal HR <110 at rest if EF >40% and asx ( NEJM 2010;362:1363)
AV node ablation + PPM as a last resort ( NEJM 2001;344:1043; 2002;346:2062)
• Rhythm control : no clear survival benefit vs. rate cntl ( NEJM 2002;347:1825 & 2008;358:2667)
Consider if sx w/ rate cntl, difficult to cntl rate, ? unable to anticoag, ? benefit in CRT

    Cardioversion
• Consider pharm or electrical cardioversion w/ 1st AF episode or if sx;
if AF >48 h, 2–5% risk stroke w/ cardioversion ( pharmacologic or electric ) ∴ either TEE to r/o thrombus or ensure therapeutic anticoagulation for ≥3 wk prior • Likelihood of success ∝ AF duration & atrial size; control precip. (eg, vol status, thyroid) • Consider pre-Rx w/ antiarrhythmic drugs (esp. if 1st cardioversion attempt fails) • For pharmacologic cardioversion, class III and IC drugs have best proven efficacy • If SR returns (spont. or w/ Rx), atria may be mech. stunned ; also, high risk of recurrent AF over next 3 mo. ∴ Anticoag postcardioversion ≥ 4–12 wk (? unless <48 h and low risk).
    Nonpharmacologic therapy
• Radiofrequency ablation (circumferential pulm. vein isolation; Lancet 2012;380:1509): ~80% success; reasonable alternative to AAD in sx persistent or paroxysmal AF w/o ↑↑ LA or ↓ EF (NEJM 2012;367:1587; RAAFT 2, HRS 2012) • Surgical “maze” procedure (70–95% success rate) option if undergoing cardiac surgery • LA appendage closure/resection: reasonable if another indication for cardiac surgery
percutaneous closure noninferior to warfarin, ↓ risk of ICH, but w/ procedural complic; additional studies & approaches underway (Lancet 2009;374:534; PREVAIL, ACC 2013)
    Oral anticoagulation (Chest 2012;141:e531S; EHJ 2012;33:2719; Circ 2013;127:1916)
• All valvular AF as stroke risk very high • Nonvalvular AF: stroke risk ~4.5%/y; anticoag → 68% ↓ stroke; use a risk score to guide Rx:
CHADS 2 : CHF (1 point), HTN (1), Age ≥75 y (1), DM (1), prior Stroke/TIA (2)
CHA 2 DS 2 - VASc : adds 65–74 y (1), >75 y (2); vasc dis. (1);sex (1)
score > 2 → anticoag; score 1 → consider anticoag or ASA (? latter reasonable if risk factor 65–74 y, vasc dis. or); antithrombotic Rx even if rhythm cntl
• Rx options : factor Xa or direct thrombin inhib (nonvalv only; no monitoring required) or warfarin (INR 2–3; w/ UFH bridge if high risk of stroke); if Pt refuses anticoag, consider
ASA + clopi or, even less effective, ASA alone (NEJM 2009;360:2066)

SYNCOPE
    Definition
• Symptom of sudden transient loss of consciousness due to global cerebral hypoperfusion • If CPR or cardioversion required, then SCD and not syncope (different prognosis) Etiologies ( NEJM 2002;347:878; JACC 2006;47:473; Eur Heart J 2009;30:2631)
• Neurocardiogenic (a.k.a. vasovagal, ~20%; NEJM 2005;352:1004): ↑ sympathetic