Internal Medicine

P1: SBT

0521779407-05 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:49

Atrial Fibrillation (AF) 189

■If rapid: dizziness and hypotension, shortness of breath, chest pain

tests

■Basic Test: 12-lead ECG: no recognizable discrete P waves. Irregularly

irregular QRS complexes, may be wide from aberrant conduction.

Ventricular response <40 to >180 bpm.

■Specific Diagnostic Test: Echocardiogram: identify structural heart

disease, left atrial thrombus (with transesophageal echo) and mea-

sure atrial and LV size and function

differential diagnosis

■Frequent atrial premature complexes may mimic AF but P waves

easily recognized on 12-lead ECG.

■Multifocal atrial tachycardia: irregularly irregular rate and pulse but

multiple (>2) P wave morphologies.

management

What to Do First

■Vital signs to assess hemodynamic response to rapid AF; 12 lead ECG

to measure ventricular rate and to assess acute myocardial ischemia,

infarction or pericarditis.

General Measures

■Avoid caffeine and alcohol if correlated with AF occurrence

specific therapy

Indicated for rapid ventricular response and restoration of normal sinus

rhythm (NSR)

Acute

■Emergency DC cardioversion (synchronized to R wave) to restore

NSR when a rapid ventricular response results in hypotension, pul-

monary edema, or ischemia.

■In stable patients: beta blockers or calcium channel blockers (ver-

apamil, diltiazem), either IV or PO, to slow ventricular response.

Digoxin less effective.

■Cardioversion to NSR without anticoagulation if AF <48 hours dura-

tion or atrial clot is excluded by transesophageal echo (92% sensitiv-

ity and 98% specificity).

■Cardioversion: DC shock, IV ibutilide (30% success rate), IV or PO

procainamide, sotalol, propafanone or PO amiodarone. (IV amio-

darone not established).