Internal Medicine

P1: SBT

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

190 Atrial Fibrillation (AF)

Chronic

■Warfarin for all patients with high-risk factors (TIA, embolism, CVA,

hypertension, heart failure or poor LV systolic function, age≥75, age

≥60 with diabetes mellitus or coronary artery disease, thyrotoxicosis,

rheumatic valve disease, prosthetic valves, persistent atrial throm-

bus). Aspirin for age <60 with lone AF, or with heart disease but no

risk factors (no heart failure, hypertension, or LVEF <0.35) and age

≥60 without above risk factors

■Restore NSR: DC cardioversion or antiarrhythmic Rx. Before car-

dioversion rule out atrial clot by transesophageal echo; otherwise

warfarin Rx; goal: INR of 2–3 for 4 weeks before cardioversion.

■12 months after successful cardioversion: without antiarrhythmic

Rx: 20–40% in NSR; with antiarrhythmic Rx: 40–50% in NSR. If NSR,

discontinue warfarin after 2–3 mos.

■Maintain NSR:

■Propafenone, sotalol (in patients without reduced LV function or

prior infarction), or amiodarone. In AF <6 mos, amiodarone more

effective than propafenone or sotalol (69% vs 39% in NSR after

1 year).

■Control of ventricular response in chronic AF:

■Beta-blockers and calcium channel blockers. Digoxin much less

effective in ambulatory patients. Try amiodarone+beta blocker

when rate control difficult.

■Radiofrequency (RF) ablation of AV node (AVN) with implantation of

a permanent cardiac pacemaker. Selected patients with paroxysmal

AF: ablation of ectopic atrial focus from pulmonary veins, or isolation

of pulmonary veins around the ostia with RF ablation, with a success

rate of 70–90% (6–24 month follow-up). The long-term success rate

of RF ablation in patients with persistent or chronic AF has not been

established.

Side Effects & Contraindications

■Potentially life-threatening pro-arrhythmic event due to antiar-

rhythmic therapy, especially with reduced LV function

■Clinically significant AV nodal block with combination of beta

blocker and amiodarone

■Drug toxicity

follow-up

■Beta-blockers and calcium channel blockers during acute treatment:

monitor BP and HR