title: Assessment of cardiovascular dynamics by pressure-area relations in pediatric patients with congenital heart disease.
abstract: OBJECTIVE
  It is particularly useful to separately quantify the ventricular contractility and loading conditions for a better understanding of the cardiovascular dynamics in congenital heart disease, where abnormalities in chamber and loading properties may coexist. Furthermore, ventricular contractility and loading conditions may alter independently or simultaneously with disease progression and therapeutic intervention. The objectives of the present study were (1) to test whether ventricular pressure-area analysis can provide such quantitation among patients with various forms of congenital heart disease, (2) to reveal basal cardiovascular interaction in congenital heart disease by means of pressure-area analysis, and (3) to test the feasibility of this method in a simplified and less invasive form to further enhance its clinical value.
  
  
  METHODS
  We constructed pressure-area loops during caval occlusion by using transthoracic echocardiographic automated border detection combined with ventricular pressure recordings in 59 pediatric patients with congenital heart disease and in 7 normal control subjects.
  
  
  RESULTS
  Area measurements obtained by automated border detection were highly reproducible, and area changes reflected volume changes. The pressure-area data provided load-independent measures of contractility, which were consistently increased by use of dobutamine (P <.05). End-systolic and arterial elastance individually quantified simultaneous changes in ventricular contractility and loading with milrinone infusion and predicted net cardiac performance. The pressure-area analysis better characterized the ventricular contractile states under a variety of loading conditions in congenital heart disease, whereas predominant load dependence of conventional indices confounded them. Furthermore, pressure-area relations were reasonably estimated from a single beat and from aortic pressure data during abdominal compression.
  
  
  CONCLUSIONS
  Pressure-area analysis should provide a useful modality with which to assess cardiovascular dynamics in pediatric patients with congenital heart disease in more detail and should thus help improve the management of patients with this disease.
authors.affiliation: Department of Pediatric Cardiology, Saitama Heart Institute, Saitama Medical School Hospital, Saitama, Japan. hsenzaki@saitama-med.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Senzaki
authors.forename: C H
authors.initials: CH
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Masutani
authors.forename: M
authors.initials: M
authors.lastname: Taketazu
authors.forename: J
authors.initials: J
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: N
authors.initials: N
authors.lastname: Sasaki
authors.forename: H
authors.initials: H
authors.lastname: Asano
authors.forename: S
authors.initials: S
authors.lastname: Kyo
authors.forename: Y
authors.initials: Y
authors.lastname: Yokote
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001830:Body Surface Area; D002316:Cardiotonic Agents; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D018450:Disease Progression; D004280:Dobutamine; D017548:Echocardiography, Transesophageal / Q000379:methods* / Q000592:standards; D005240:Feasibility Studies; D006330:Heart Defects, Congenital / Q000145:classification / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000592:standards; D007223:Infant; D012720:Severity of Illness Index; D013318:Stroke Volume; D017725:Ventricular Pressure
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine