Effects of flecainide on left ventricular pressure gradient and symptoms in obstructive hypertrophic cardiomyopathy: a comparison of flecainide and disopyramide.
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.
['Haruki|Shintaro|S|', 'Minami|Yuichiro|Y|', 'Suzuki|Atsushi|A|', 'Hagiwara|Nobuhisa|N|']
D000284:Administration, Oral D000889:Anti-Arrhythmia Agents D002312:Cardiomyopathy, Hypertrophic D004206:Disopyramide D004305:Dose-Response Relationship, Drug D004452:Echocardiography D005260:Female D005424:Flecainide D005500:Follow-Up Studies D006352:Heart Ventricles D006801:Humans D008297:Male D008875:Middle Aged D012189:Retrospective Studies D013997:Time Factors D016896:Treatment Outcome D014694:Ventricular Outflow Obstruction D017725:Ventricular Pressure
Obstruction Hypertrophic cardiomyopathy Antiarrhythmic agents