Medtronic Plc. · NYSE:MDT
Medtronic — Technical Presentation (2022)
13 slides from Medtronic's technical presentation, 2022
Slide 1: Echocardiography considerations
Echocardiography considerations Detecting low-flow, low-gradient aortic stenosis The information in this document is intended for educational purposes based on an identified need, is not meant as a substitute for the Instructions for Use or product training, and is not intended to constitute medical
Slide 2: Aortic stenosis variations
Aortic stenosis variations Incidence/prevalence Low-flow, low-gradient AS is defined by AVA ≤ 1.0 cm2 but with gradients in non-severe range (<40mmHg).1 Up to 30% of AS cases match this definition as follows:2 Low-flow, low-gradient AS Low-flow, low-gradient AS with preserved LVEF3 with reduced LVEF
Slide 3: Aortic stenosis variations
Aortic stenosis variations Illustrations refer to examples of Severe AS with the AVA < 1.0 cm² Normal LVEF Low-flow, Low-flow, Normal flow low-gradient AS low-gradient AS High gradient with preserved LVEF with reduced LVEF Diastole Systole 3
Slide 4: Aortic stenosis diagnosis
Aortic stenosis diagnosis Pitfalls in assessing severity • Body habitus and anatomy Related to patient • General status: postoperative, acute illness, chest disorders, COPD, etc. • Physiology: rate, rhythm • Operator skill and experience • Mistaking mitral regurgitation for AS • Pitfalls: max veloci
Slide 5: Assessment of max velocity and mean gradient
Assessment of max velocity and mean gradient Use of multiple windows is imperative to avoid mis-evaluation of AS severity Apical Supra sternal notch • se of multiple windows is required U to avoid underestimation of max aortic velocity due to nonparallel intercept angle between ultrasound beam and a
Slide 6: Assessment of max velocity and mean gradient
Assessment of max velocity and mean gradient Use of multiple windows is imperative to avoid mis-evaluation of AS severity • Vmax was located outside the apical imaging window in 61% of patients.1 • eglecting the non-apical imaging windows resulted in the misclassification N (underestimation) of AS s
Slide 7: LVOT diameter
LVOT diameter Can be the larger source of an error in the AVA continuity equation1-7 • VOT diameter is measured in the parasternal L long-axis view, with the optimal imaging plane through the long axis of the aorta (anterior and posterior walls of the aortic root parallel with the maximal aortic dia
Slide 8: LVOT velocity
LVOT velocity Correct sample volume placement is critical • LVOT velocity is recorded with PW Doppler B from the apical position, in either the apical long-axis view or the anteriorly angulated four-chamber view (“five-chamber view”). • PW sample volume should be positioned just proximal to the aort
Slide 9: Doppler velocity index (DVI)
Doppler velocity index (DVI) A flow-independent measure of degree of valve obstruction • Ratio of LVOT to aortic valve velocities • Also known as “Dimensionless index” • easures degree of flow acceleration through M aortic valve • Independent of flow (useful for serial follow-up) • DVI ≤ 0.25 consis
Slide 10: Doppler velocity index (DVI): ratio of LVOT to aortic valve velocities
Doppler velocity index (DVI): ratio of LVOT to aortic valve velocities Can use velocity time integral (VTI) or peak velocity LVOT VTI: 16.4 LVOT peak velocity: 82.7 cm/sec Aortic valve VTI: 19.4 LVOT peak velocity: 109 cm/sec DVI (VTI) = 16.4/19.4 = 0.84 DVI (peak) = 82.7/109 = 0.76 10
Slide 11: Abnormal Doppler velocity index (DVI): ratio of LVOT to aortic valve velocities
Abnormal doppler velocity index (DVI): ratio of LVOT to aortic valve velocities Do you use peak velocity or DVI? DVI (VTI) = 9.91 cm/76.6 cm = 0.13 11
Slide 12: LVOT obstruction
LVOT obstruction LVOT region should be carefully evaluated The safety and effectiveness of the bioprosthesis In patients with bulging basal interventricular for AVR have not been evaluated in patient septum (sigmoid septum) or hyperdynamic LV populations presenting with severe basal septal function,
Slide 13: medtronic.eu/DetectAS
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