title: Clinical features of hypertrophic cardiomyopathy in the young.
abstract: BACKGROUND
  We analysed the experience with hypertrophic cardiomyopathy in two paediatric centres to establish the differences from older patients.
  
  
  METHODS
  Out of 45 young patients seen from 1974 to 1999, we included 38. Criterions for exclusion were secondary forms, or association with severe congenital cardiac disease which could alter the outcome.
  
  
  RESULTS
  The patients presented at the age of 5.7 years, and were followed for 7.0 years. The 34 patients referred because of a murmur or cardiomegaly were older than the four with heart failure, presenting at 6.2 as opposed to 2.1 years of age, p = 0.08. Of the patients, 29 (76%) had primary cardiomyopathy, while 9 (24%) had secondary forms associated with Noonan's and LEOPARD syndromes. Familial tendency was ascertained in 7 patients (18%). The septal thickness in mm/m2 at presentation was greater in patients under 2 years than in older children (29 vs 18, p = 0.02). Obstructive hypertrophic cardiomyopathy was found in 17 patients (45%), with six of these having mild associated congenital cardiac defects. Nine had symptomatic arrhythmias. Overall, treatment was medical in 31, with DDD pacing used in 5, and surgery, radiofrequency ablation, and transplantation in one patient each. Total mortality was 24%, at a rate of 4.3% per year. Four patients died in heart failure and 5 had sudden death. Those in failure were significantly younger (p = 0.01).
  
  
  CONCLUSIONS
  Hypertrophic cardiomyopathy in the young is characterized by referral for murmur or heart failure; frequent secondary forms; the obstructive variant being as common as the non-obstructive form; a mortality rate similar to that for adults attending tertiary centres; and less frequent familial forms than in older populations.
authors.affiliation: Division of Cardiology, Hospital de Niños, Córdoba, Argentina.
authors.forename: Eva
authors.initials: E
authors.lastname: Bruno
authors.forename: Héctor
authors.initials: H
authors.lastname: Maisuls
authors.forename: Ernesto
authors.initials: E
authors.lastname: Juaneda
authors.forename: Eduardo
authors.initials: E
authors.lastname: Moreyra
authors.forename: Luis E
authors.initials: LE
authors.lastname: Alday
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001118:Argentina / Q000453:epidemiology; D006328:Cardiac Catheterization; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D002648:Child; D015331:Cohort Studies; D016757:Death, Sudden, Cardiac; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D015996:Survival Rate