title: Effect of beta-blockade on symptomatic dexamethasone-induced hypertrophic obstructive cardiomyopathy in premature infants: three case reports and literature review.
abstract: OBJECTIVE
  The objective of this study was to assess the efficacy of beta-blockade on clinically significant left ventricular outflow tract obstruction in premature infants treated with dexamethasone because of bronchopulmonary dysplasia.
  
  
  METHODS
  Case reports are presented of three premature infants (mean gestational age 27 weeks) cared for in the intensive care nursery in whom clinically significant septal hypertrophy and left ventricular outflow tract obstruction developed during dexamethasone treatment for bronchopulmonary dysplasia. The infants were treated with oral propranolol. Serial physiologic and echocardiographic parameters were followed. Physiologic data were analyzed with an analysis of variance, with the Kruskal-Wallis test used for nonparametric data. A p value < 0.05 was considered statistically significant.
  
  
  RESULTS
  Oral administration of the beta-blocker propranolol resulted in clinical and echocardiographic improvement of the left ventricular outflow tract obstruction. One patient had a lower average heart rate and two patients had lower average mean blood pressure values during propranolol treatment, none of which was clinically significant. None of the patients had worsening of the respiratory status.
  
  
  CONCLUSIONS
  beta-blockade treatment was well tolerated and may be beneficial in relieving symptomatic steroid-induced left ventricular outflow tract obstruction in premature infants.
authors.affiliation: Department of Pediatrics, Thomas Jefferson University Hospital, Philadelphia, Pa., USA.
authors.forename: K I
authors.initials: KI
authors.lastname: Fritz
authors.forename: A M
authors.initials: AM
authors.lastname: Bhat
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D001997:Bronchopulmonary Dysplasia / Q000188:drug therapy; D002312:Cardiomyopathy, Hypertrophic / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000188:drug therapy*; D003907:Dexamethasone / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D005938:Glucocorticoids / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D011433:Propranolol / Q000627:therapeutic use*; D014463:Ultrasonography
chemical_list: D000319:Adrenergic beta-Antagonists; D005938:Glucocorticoids; D003907:Dexamethasone; D011433:Propranolol