tailieunhanh - Ebook Aortic stenosis - Case-Based diagnosis and therapy (1st edition): Part 2

(BQ) Part 2 book "Aortic stenosis - Case-Based diagnosis and therapy" presents the following contents: Reverse area and gradient mismatch - the discordance of a large valve area and high gradients, prosthetic aortic valves and diagnostic challenges, risk prediction models, guidelines, special populations and outcomes, surgical management of aortic valve stenosis, balloon aortic valvuloplasty,. | Area and Gradient Mismatch The Discordance of a Small Valve Area and Low Gradients 8 Laura M. Franey Steven J. Lester Frances O. Wood and Amr E. Abbas Abstract While the clinical severity of aortic stenosis AS is based largely on symptoms indications for surgical aortic valve replacement SAVR and or transcutaneous TAVR rely upon calculated estimates of the hemodynamic significance and degree of valvular stenosis. Severe AS is defined as an aortic valve area AVA cm2 or indexed AVA cm2 m2 mean trans-valvular pressure gradient AP 40 mmHg and or peak trans-aortic velocity 4 m s by Doppler echocardiography. Whether the above conditions must be met individually or collectively remains unclear. As noted area gradient match occurs when both the AVA and AP fall within the severe range. This may occur regardless of the presence of normal or abnormal ejection fraction and regardless of the presence or absence of low flow defined as a stroke volume index on echocardiography 35 ml m2 . However the AVA may be in the severe range while the gradient may be in the non-severe range. This has been referred to as area gradient mismatch and will be discussed further in this chapter. Keywords Aortic stenosis severity Surgical aortic valve replacement SAVR Transcutaneous aortic valve replacement TAVR Area gradient match Low flow area-gradient mismatch . Franey MD . Wood MD . Abbas MD FACC FSCAI FSVM FASE RPVI Department of Cardiovascular Medicine Beaumont Health Oakland University William Beaumont School of Medicine Royal Oak MI USA e-mail aabbas@ . Lester MD Department of Medicine Mayo Clinic Scottsdale AZ USA Springer-Verlag London 2015 . Abbas ed. Aortic Stenosis Case-Based Diagnosis and Therapy DOI 978-1-4471-5242-2_8 117 118 . Franey et al. Introduction While the clinical severity of aortic stenosis AS is based largely on symptoms indications for surgical aortic valve replacement SAVR and or transcutaneous TAVR