title: In vitro evaluation of the effect of aortic compliance on pediatric intra-aortic balloon pumping.
abstract: OBJECTIVES: To evaluate the effect of aortic compliance on pediatric intra-aortic balloon pumping (IABP). DESIGN: In vitro study using a mechanical model of the pediatric left heart circulation. SETTING: Cardiovascular fluid dynamics research laboratory. SUBJECT: Pulsatile flow system simulating the pediatric left heart circulation and two different aortas with compliances comparable to those of the pediatric aorta (0.12 and 0.07 mL/mm Hg). INTERVENTIONS: Measurements were made at a baseline peak aortic flow of 4 L/min, at simulated shock (1.7 L/min), and with 1:1 IABP (rates, 130 and 150 bpm; balloon volumes, 2.5 and 5.0 mL). MEASUREMENTS AND MAIN RESULTS: Peak flow rates were measured in the ascending aorta, coronary arterial system, and brachiocephalic arterial systems. Aortic pressure was measured in the ascending aorta. For both aortas (0.12 and 0.07 mL/mm Hg), IABP resulted in diastolic augmentation (38 +/- 8 and 43 +/- 16 mm Hg) and afterload reduction (4 +/- 2 and 6 +/- 3 mm Hg). For both aortas, compared to shock, IABP resulted in significant increases in coronary arterial and brachiocephalic arterial flow and aortic pressure for both aortas. Aortic flow significantly increased only in the less-compliant aorta. CONCLUSIONS: In a laboratory model of pediatric left heart circulation, IABP results in diastolic augmentation, afterload reduction, and improved hemodynamics, even in aortas of greater compliance.
authors.affiliation: Departments of Pediatrics and Surgery, University of Utah, Salt Lake City, UT E-mail: pclminic@ihc.com
authors.forename: L L
authors.initials: LL
authors.lastname: Minich
authors.forename: L Y
authors.initials: LY
authors.lastname: Tani
authors.forename: J A
authors.initials: JA
authors.lastname: Hawkins
authors.forename: R R
authors.initials: RR
authors.lastname: Bartkowiak
authors.forename: M L
authors.initials: ML
authors.lastname: Royall
authors.forename: G M
authors.initials: GM
authors.lastname: Pantalos