A reappraisal on lidocaine-sensitive repetitive, uniform atrial tachycardia.
BACKGROUND
Lidocaine sensitive, repetitive atrial tachycardia is an unusual arrhythmia whose electrophysiologic substrate remains undefined. We aimed to analyze the electropharmacologic characteristics of this arrhythmia with emphasis on its cellular substrate and response to drug challenges.


METHODS
We retrospectively analyzed a series of 18 patients from an electrocardiographic and electrophysiologic perspective and the response to pharmacological challenge.


RESULTS
There was no evidence of structural heart disease in 12 patients, 4 patients presented with systemic hypertension; one patient had a prior myocardial infarction and one a mitral valve prolapse. The arrhythmia depicted a consistent pattern in nine patients. The first initiating ectopic beat showed a long coupling interval, the cycle length of the second atrial ectopic beat presented the shortest cycle length and a further prolongation was apparent towards the end of the atrial salvos. Conversely, in the other nine cases, the atrial tachycardia cycle length was erratic. The arrhythmia was suppressed by asynchronous atrial pacing at cycle lengths longer than those of the atrial tachycardia. Intravenous lidocaine eliminated the arrhythmia in all patients, but intravenous verapamil suppressed the atrial tachycardia in only two patients while adenosine caused a transient disappearance in 2/8 patients. Only one patient responded to all the three agents. Radiofrequency ablation was successfully performed in 10 patients.


CONCLUSIONS
Repetitive uniform atrial tachycardia can be sensitive to lidocaine. In few cases, this rare focal arrhythmia may be also suppressed by adenosine and/or verapamil, which suggests a diversity of electrophysiologic substrates that deserve to be accurately identified.
Centro de Arritmias Cardíacas de la Ciudad de Buenos Aires, Division of Cardiology, Hospital J. M. Ramos Mejía, and Pontificia Universidad Católica Argentina Santa María de los Buenos Aires, Buenos Aires, Argentina. hugoariel@garro.com
Hugo A
HA
Garro
Marcelo V
MV
Elizari
Adrian
A
Baranchuk
Francisco
F
Femenía
Pablo A
PA
Chiale
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D017115:Catheter Ablation; D003131:Combined Modality Therapy; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008012:Lidocaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013617:Tachycardia, Supraventricular / Q000188:drug therapy* / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome; D014700:Verapamil / Q000627:therapeutic use
D000889:Anti-Arrhythmia Agents; D008012:Lidocaine; D014700:Verapamil