P1: SBT
0521779407-05 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:49
Atrial Tachycardia (AT) 197Atrial Tachycardia (AT)................................
EDMUND C. KEUNG, MD
history & physical
History
■Underlying structural heart disease: coronary, hypertensive heart
disease, mitral valve prolapse, after surgery for congenital heart dis-
ease (incisional reentry).
■COPD, acute alcohol ingestion and digoxin toxicity.Signs & Symptoms
■Palpitation, regular or irregular rapid pulse.
■Dizziness, hypotension, syncope, shortness of breath, chest pain.tests
■Basic Tests
➣12-lead ECG:
➣Narrow QRS tachycardia unless pre-existing conduction defect
or rate-related aberrant ventricular conduction. Atrial rate 150–
200 bpm. Ectopic P wave precedes each QRS complex (long RP
tachycardia). AV nodal block frequent.
➣Positive P wave in lead V1 predicts a left atrial focus (93% sensi-
tivity and 88% specificity).
➣Positive or biphasic P wave in lead AVL predicts a right atrial focus
(88% sensitivity and 79% specificity).
■Specific Diagnostic Test
➣Electrophysiology study to confirm AT (usually performed in
conjunction of RF ablation)differential diagnosis
■Sinus tachycardia, atrial flutter, AV re-entry tachycardia, and atrial
tachycardia. Diagnostic electrophysiology study often required to
differentiate three types of AT: automatic, triggered and reent-
rant.management
What to Do First
■Vital signs to assess hemodynamic response; 12 lead ECG to assess
acute myocardial ischemia, infarction