Pressure half-time does not always predict mitral valve area correctly.

Loyd, DanLinköpings universitet,Mekanisk värmeteori och strömningslära,Tekniska högskolan (författare)

A theory is presented elucidating factors that influence the pressure half-time. By combining the Bernoulli and continuity equations and making certain assumptions about the shape of the atrioventricular pressure difference decay, it can be shown that valve area, volume transported across that area, and initial pressure difference influence the pressure half-time according to a formula in which the pressure half-time is related to V/(Ao square root of delta po), where V is the transported volume across the orifice with the area Ao, and delta po is the initial pressure difference across that area. In a subsequent hydraulic model experiment pressure half-time was determined for three different hole areas, with various initial volumes and initial pressure gradients. We did not obtain a unique relation between the pressure half-time and area. Instead the results supported our theory, and we found a close linear relationship between area and V/(T0.5 square root of delta po) (correlation coefficient [r] = 0.998), as predicted in the theory (T0.5 = pressure half-time). Clinical examples in which the pressure half-time may be misleading in the assessment of severity of mitral stenosis are presented.

Ask, PerLinköpings universitet,Fysiologisk mätteknik,Tekniska högskolan(Swepub:liu)peras02 (författare)
Wranne, BengtÖstergötlands Läns Landsting,Linköpings universitet,Klinisk fysiologi,Hälsouniversitetet,Fysiologiska kliniken US(Swepub:liu)benwr76 (författare)
Linköpings universitetMekanisk värmeteori och strömningslära (creator_code:org_t)

Ingår i:Journal of the American Society of Echocardiography1:5, s. 313-3210894-73171097-6795

Om ämnet

TEKNIK OCH TEKNOLOGIER: TEKNIK OCH TEKNO ...; och Maskinteknik; och Strömningsmekani ...

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.