PROSTHETIC HEART VALVE FUNCTION AS ASSESSED BY THE MAGNITUDEOF TURBULENCE ( ) DURING FLOW ACCELERATION PHASE

Research Project

Project/Area Number	61570679
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Thoracic surgery
Research Institution	KITASATO UNIVERSITY
Principal Investigator	SHIZUO HANYA KITASATO UNIVERSITY, ASSOCIATED PROFESSOR, 医学部, 講師 (80075522)
Co-Investigator(Kenkyū-buntansha)	AKIRA ISHIHARA KITASATO UNIVERSITY, PROFESSOR, 医学部, 教授 (20050338)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	Posthetic heart valve / Pressure loss coefficient / Turbulence / multisensor catheter / 人工弁の機能評価 / 加速期血流の乱流遷移 / 乱流強度 / カテ先電磁流速・圧力計
Research Abstract	The flow obstruction in aortic valve implants was studied in 21 patients with Bjork-Shiley (9), St. Jude Medical (10) or porcine Carpentier-Edwards (2) prosthetic aortic valves. The pressure loss coefficient increased by transition from laminar to turbulence during flow acceleration phase was used as a measure of the flow obstruction. The increase of the pressure loss coefficient (<DELTA><lambda>) was calculated by the folowing equation. <DELTA><lambda>= <DELTA>p / U^2 ( : blood density) Peak blood velocity (U) in the ascending aorta and anacrotic pressure drop (DELTA)p in the upstroke of the aortic pressure curve were obtained simultaneously using a multisensor catheter. Results were as follows. Valve size: 21mm 23mm 25mm 27mm 29mm Bjork-Shiley - 1.90<plus-minus>0.49 0.60 0.40<plus-minus>0.40 0<plus-I.DELT St. Jude Medical 0.57<plus-minus>0.43 0.40<plus-minus>0.57 0 - 0< Porcine valve - 2.45<plus-minus>1.95 - - nu In the 23mm valve size, the St. Jude valve has an average<DELTA><lambda> of 0.40, compared with 1.90 and 2.45 for the Bjork-Shiley and Carpentier-Edwards (porcine) valves, respectively. The mean<DELTA><lambda> calculated in the patients with 23mm porcine valve showed the highest value. For each valve size studied, the <DELTA><lambda> were smaller for the St. Jude than for the corresponding size Bjork-Shiley valves. It is concluded that comparison of the <DELTA><lambda> indicates that the St. Jude valve creates less resistance to flow than the Bjork-Shiley and porcine valves in current clinical use, especially in the small sizes.