title: Utility of Routine Exercise Testing to Detect Rate-Related QRS Widening in Patients Without Structural Heart Disease on Class Ic Antiarrhythmic Agents (Flecainide and Propafenone).
abstract: Class Ic antiarrhythmic agents are effective in the treatment of various atrial tachyarrhythmias. They are known to cause rate-related QRS widening in the presence of structural heart disease, which can lead to life-threatening arrhythmias. The role of routine exercise electrocardiography in patients without structural heart disease is unknown. All patients initiated on class Ic antiarrhythmic agents and who had exercise electrocardiography performed from June 2009 to June 2013 were included. Symptom-limited treadmill electrocardiography was performed to detect significant QRS widening at peak exercise (defined as an increase of >25% of baseline QRS). Fifty-six patients were included in the study. All patients were screened for structural heart disease before initiation of the medication. Significant QRS widening and atrial tachycardia occurred in a single patient, which terminated with cessation of exercise. This patient had a history of tachycardia-mediated cardiomyopathy with normalization of ejection fraction 3 years before being placed on flecainide. In conclusion, routine exercise testing to detect QRS widening is not warranted in patients with no structural heart disease.
authors.affiliation: Division of Cardiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas. Electronic address: srivallurupalli@gmail.com.
authors.forename: Srikanth
authors.initials: S
authors.lastname: Vallurupalli
authors.affiliation: Division of Cardiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
authors.forename: Naga Venkata K
authors.initials: NV
authors.lastname: Pothineni
authors.affiliation: Division of Cardiology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Deshmukh
authors.affiliation: Division of Cardiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
authors.forename: Hakan
authors.initials: H
authors.lastname: Paydak
mesh_terms: D001131:Arkansas / Q000453:epidemiology; D009202:Cardiomyopathies / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D004452:Echocardiography; D004562:Electrocardiography; D005080:Exercise Test / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D005424:Flecainide / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011405:Propafenone / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013612:Tachycardia, Ectopic Atrial / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D016276:Ventricular Function / Q000187:drug effects / Q000502:physiology; D061567:Voltage-Gated Sodium Channel Blockers / Q000627:therapeutic use
chemical_list: D061567:Voltage-Gated Sodium Channel Blockers; D011405:Propafenone; D005424:Flecainide