Internal Medicine

P1: SBT

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

198 Atrial Tachycardia (AT) Atrioventricular Block

General Measures

■Identify and initiate treatment of underlying conditions responsi-

ble for AT. Avoidance of caffeine and alcohol, if correlated with SVT

occurrence

specific therapy

Restore sinus rhythm

Acute

■Slow rapid ventricular response with IV beta blockers (metopro-

lol, esmolol) or calcium channel blockers (verapamil, diltiazem), or

digoxin. 56% termination with adenosine. If AT occurs in the pres-

ence of digoxin, discontinue digoxin and administer KCl to maintain

normal serum K+level.

Chronic

■Class IA, IC and III antiarrhythmic agents to restore and maintain

NSR.

■Radio frequency ablation of atrial ectopic focus (a different focus

may occur after initial success)

Side Effects & Contraindications

■Excessive suppression of AVN or sinus node activity with beta block-

ers or calcium channel blockers. Pro-arrhythmic effects from anti-

arrhythmic agents.

follow-up

■During beta blocker and calcium channel blocker Rx monitor BP and

HR and AV conduction. Periodic ECG to monitor AV conduction, QRS

and QT duration during Class I and III treatment. Holter to ascertain

effectiveness of treatment.

complications and prognosis

■Cardiomyopathy with incessant AT

Atrioventricular Block.................................

EDMUND C. KEUNG, MD

history & physical

History

■Ischemic heart disease and myocardial infarction