title: Effects of flecainide on left ventricular pressure gradient and symptoms in obstructive hypertrophic cardiomyopathy: a comparison of flecainide and disopyramide.
abstract: It remains unclear whether flecainide, a Class I antiarrhythmic drug, improves left ventricular pressure gradient (LVPG) or symptoms in patients with obstructive hypertrophic cardiomyopathy (HCM). Our study evaluated the long-term efficacy of flecainide, compared to disopyramide, when administered orally, on LVPG and symptoms in obstructive HCM patients. Among 164 obstructive HCM patients, 15 were administered oral flecainide therapy and 33 administered oral disopyramide therapy. LVPG declined from 79.8 ± 36.6 to 39.2 ± 36.7 mmHg (p = 0.003) after flecainide therapy and from 74.5 ± 26.4 to 31.4 ± 24.8 mmHg (p < 0.001) after disopyramide therapy. The percent reduction in LVPG was -47.9 ± 43.2 % in patients treated with flecainide, comparable to the results for those treated with disopyramide (-57.1 ± 33.0 %; p = 0.425). We found no significant differences in improvement in NYHA functional class between patients treated with flecainide and those treated with disopyramide (p = 0.331). Patients treated with flecainide exhibited no significant adverse side effects, and there was no need for myectomy or alcohol septal ablation to reduce LVPG and symptoms. Improvements in LVPG and symptoms were similar in patients treated with flecainide and patients treated with disopyramide, suggesting that flecainide is a potentially useful alternative for symptomatic obstructive HCM patients, particularly those with disopyramide-induced vagolytic side effects, narrow angle glaucoma, or prostatic hyperplasia and pre-existing urination difficulties. Our data must be viewed with caution, however, in view of the small number of study patients. Flecainide therapy will require further proof of safety before it can be routinely recommended in patients with symptomatic obstructive HCM.
authors.affiliation: Department of Cardiology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Haruki
authors.affiliation: Department of Cardiology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. yuichiro24@celery.ocn.ne.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Minami
authors.affiliation: Department of Cardiology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Department of Cardiology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Hagiwara
mesh_terms: D000284:Administration, Oral; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage; D002312:Cardiomyopathy, Hypertrophic / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D004206:Disopyramide / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004452:Echocardiography; D005260:Female; D005424:Flecainide / Q000008:administration & dosage*; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D017725:Ventricular Pressure / Q000187:drug effects* / Q000502:physiology
chemical_list: D000889:Anti-Arrhythmia Agents; D004206:Disopyramide; D005424:Flecainide
keywords: Antiarrhythmic agents; Hypertrophic cardiomyopathy; Obstruction