Clinical usefulness of electrophysiologic testing in patients with ventricular tachycardia and chronic chagasic cardiomyopathy treated with amiodarone or sotalol.
BACKGROUND
This study assessed the role of electrophysiologic testing to identify therapeutic strategies for the treatment of patients with sustained ventricular tachycardia (VT) and chronic chagasic cardiomyopathy treated with amiodarone or sotalol.


RESULTS
One hundred fifteen patients [69 men (60%); mean age 52 +/- 10 years] with chagasic cardiomyopathy presenting with symptomatic VT were studied after loading with Class III antiarrhythmic drugs; 78 had a history of sustained VT, and 37 with symptomatic nonsustained VT had sustained VT induced at baseline electrophysiologic study. All but 12 patients also underwent baseline electrophysiologic study. Mean left ventricular ejection fraction was 0.49 +/- 0.14. Based on results of electrophysiologic study after loading with Class III drugs, patients were divided into three groups: group 1 (n = 23) had no sustained VT induced; group 2 (n = 45) had only tolerated sustained VT induced; and group 3 (n = 47) had hemodynamically unstable sustained VT induced. After a mean follow-up of 52 +/- 32 months, total mortality rate was 39.1%; it was significantly higher in group 3 than in groups 2 and 1 [69%, 22.2%, and 26%, respectively, P < 0.0001, hazard ratio (HR) 10.4, 95% confidence interval (CI) 3.8, 21.8]. There was no significant difference in total mortality rate between groups 1 and 2 (P = 0.40, HR 1.5, 95% CI 0.75, 4.58). Cardiac mortality and sudden cardiac death rates also were higher in group 3 patients.


CONCLUSIONS
In patients with chagasic cardiomyopathy and sustained VT, electrophysiologic testing can predict long-term efficacy of Class III antiarrhythmic drugs. This may help in the selection of patients for implantable cardioverter defibrillator therapy.
Leite
Luiz R
LR
Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
Fenelon
Guilherme
G
Simoes
Aloyr
A
Silva
Georgia G
GG
Friedman
Paul A
PA
de Paola
Angelo A V
AA
D000328:Adult; D000638:Amiodarone / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001938:Brazil; D002598:Chagas Cardiomyopathy / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology; D004359:Drug Therapy, Combination; D004599:Electric Stimulation Therapy; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D055502:Secondary Prevention; D013015:Sotalol / Q000627:therapeutic use*; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality / Q000628:therapy
D000889:Anti-Arrhythmia Agents; D013015:Sotalol; D000638:Amiodarone