title: Echocardiographic characteristics predicting efficacy of drug therapy in patients with hypertrophic obstructive cardiomyopathy.
abstract: BACKGROUND
  The efficacy of long-term drug therapy for patients with hypertrophic obstructive cardiomyopathy (HOCM) remains unclear. This study was performed to characterize the echocardiographic findings of patients responsive to drug therapy.
  
  
  METHODS
  Left ventricular outflow tract (LVOT) gradient and morphologic characteristics of the septum, posterior wall, and mitral valve were measured echocardiographically in 35 Japanese patients. The mean follow-up time was 41+/-22 months.
  
  
  RESULTS
  Long-term drug therapy was effective in 14 patients and ineffective in 21 patients. Five of the refractory patients required mitral valve replacement to become free of symptoms. Only 5 of 21 patients whose LVOT gradient was 100 mm Hg were responsive to drug therapy, whereas 9 of 14 patients whose LVOT gradient was <100 mm Hg were responsive to drug therapy. Seven of eight patients with an asymmetric septal hypertrophy (ASH) ratio >==1.3 and LVOT gradient <100 mm Hg were responsive to drug therapy. Only 3 of 16 patients with an ASH ratio <1.3 were responsive to drug therapy. There was no correlation between the efficacy of drug therapy and the morphology of the mitral valve or the width of the LVOT.
  
  
  CONCLUSIONS
  Our results demonstrate that drug therapy effectively reduces the LVOT gradient in patients with asymmetric septal hypertrophy and a less severe LVOT gradient.
authors.affiliation: Department of Cardiology, The Heart Institute of Japan, Tokyo Women's Medical University, Japan. Kazuhiro_Shimaya@hm.honda.co.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shimaya
authors.forename: Akira
authors.initials: A
authors.lastname: Kurihashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Fuda
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Yajima
authors.forename: Nobuo
authors.initials: N
authors.lastname: Yamami
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Shiga
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Sakomura
authors.forename: Naoki
authors.initials: N
authors.lastname: Matsuda
authors.forename: Naoko
authors.initials: N
authors.lastname: Ishizuka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kasanuki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000188:drug therapy