title: Characterization of left ventricular diastolic function by tissue Doppler imaging and clinical status in children with hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Conventional transmitral Doppler indices are unreliable in assessing clinical status in patients with hypertrophic cardiomyopathy (HCM) because they are affected by loading conditions. This study sought to determine whether tissue Doppler velocities are predictive of adverse clinical outcomes including death, cardiac arrest, ventricular tachycardia (VT), significant cardiac symptoms, and exercise capacity in children with HCM.
  
  
  RESULTS
  We studied 80 consecutive children (median age 12 years, median follow-up 26 months) evaluated at 1 hospital from January 1999 to August 2003 compared with 80 age- and gender-matched controls. Patients underwent echocardiography, ambulatory Holter monitoring, and upright exercise testing. Children with HCM had significantly decreased early diastolic tissue Doppler velocities at the lateral mitral (13.2 versus 19.3 cm/s), tricuspid (13.3 versus 16.3 cm/s), and septal (9.4 versus 13.5 cm/s) annuli compared with controls (P<0.001 for each comparison). By forward stepwise regression analysis, early transmitral left ventricular filling velocity (E)/septal Ea ratio predicted death, cardiac arrest, or VT (r=0.610, R2=0.37, P<0.001). Peak oxygen consumption (VO2) was most predictive of children who developed symptoms (r=0.427, R2=0.182, P<0.001). Peak VO2 correlated inversely with E/Ea septal ratio (r=-0.740, P<0.01).
  
  
  CONCLUSIONS
  Transmitral E/septal Ea ratio predicts children with HCM who are at risk of adverse clinical outcomes including death, cardiac arrest, VT, and significant cardiac symptoms. Peak VO2 correlated with peak exercise capacity in HCM patients.
authors.affiliation: Lillie Frank Abercrombie Section of Pediatric Cardiology, Texas Children's Hospital, Houston, Tex 77030, USA.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: McMahon
authors.forename: Sherif F
authors.initials: SF
authors.lastname: Nagueh
authors.forename: Ricardo H
authors.initials: RH
authors.lastname: Pignatelli
authors.forename: Susan W
authors.initials: SW
authors.lastname: Denfield
authors.forename: William J
authors.initials: WJ
authors.lastname: Dreyer
authors.forename: Jack F
authors.initials: JF
authors.lastname: Price
authors.forename: Sarah
authors.initials: S
authors.lastname: Clunie
authors.forename: Louis I
authors.initials: LI
authors.lastname: Bezold
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Hays
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Towbin
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Eidem
mesh_terms: D000293:Adolescent; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002637:Chest Pain / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000209:etiology; D006801:Humans; D007223:Infant; D008297:Male; D010101:Oxygen Consumption; D011379:Prognosis; D011446:Prospective Studies; D016037:Single-Blind Method; D017180:Tachycardia, Ventricular / Q000209:etiology; D018608:Ultrasonography, Doppler; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology; D016277:Ventricular Function, Left; D014694:Ventricular Outflow Obstruction / Q000209:etiology / Q000503:physiopathology