scholarly journals ‘Weighing up the Load’ – A Comparison of Cardiac Magnetic Resonance Methods to Assess Valvulo-Arterial Load in Patients with Aortic Stenosis

2021 ◽  
Vol 8 (2) ◽  
pp. 88-94
Author(s):  
Sara Hungerford ◽  
Audrey Adji ◽  
Nicole Bart ◽  
Linda Lin ◽  
Michael O'Rourke ◽  
...  
Keyword(s):  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aortic Stenosis ◽  
Arterial Load

Abstract 12586: Assessing Valvuloarterial Impedance in Aortic Stenosis: A Comparison of Echocardiographic- and Cardiac Magnetic Resonance-derived Methods

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sara L Hungerford ◽  
Audrey Adji ◽  
Nicole K Bart ◽  
Linda Lin ◽  
Andrew Jabbour ◽  
...  
Keyword(s):  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aortic Stenosis ◽  
Flow Velocity ◽  
Cuff Pressure ◽  
Ventricular Outflow Tract ◽  
Left Ventricular ◽  
Applanation Tonometry ◽  
Aortic Flow ◽  
Entire Cross Section

Introduction: Valvuloarterial impedance (Z VA ) represents the valvular and arterial factors that oppose Left Ventricular (LV) ejection and is recognised as an important index to assess global LV load in patients with Aortic Stenosis (AS). Z VA is traditionally determined by Transthoracic Echocardiogram (TTE) and brachial cuff pressure. Hypothesis: Our study sought to compare Z VA-TTE with Z VA calculated using a simultaneous Cardiac Magnetic Resonance (CMR) and Applanation Tonometry (AT) (Z VA-CMR ) technique to determine whether TTE measurement of aortic flow velocity resulted in an underestimation of Z VA. Methods: Twenty AS patients underwent a protocol of CMR/AT followed by TTE. Z VA-CMR was determined as the relationship of derived aortic pressure (radial) to CMR aortic flow velocity in the frequency domain. Z VA-TTE was determined from digitised flow velocity within the left ventricular outflow tract (LVOT) on pulsed-wave Doppler and derived central pressure waveforms. Systemic vascular resistance (SVR) was calculated from mean pressure and flow. Values from both methods were compared. Results: Our study found that Z VA-TTE values (mean±SD, 638±381 dyne.s.cm -3 ) were consistently lower (p=0.07) than Z VA-CMR values (946±318 dyne.s.cm -3 ), and attribute this to an overestimation of LVOT flow velocity on TTE. SVR calculated by CMR/AT (2215±616 dyne.s.cm -5 ) was almost four times higher than TTE (618±245 dyne.s.cm -5 ) (p<0.001). This is due to more robust axi-symmetrical sampling of aortic flow across the entire cross-section of the ascending aorta (well above the stenotic jet) during CMR, than using operator-dependent TTE. Conclusions: Whilst Z VA -TTE is commonly performed in patients with AS to assess global LV load, newer methods to assess Z VA using simultaneous CMR/AT likely represent a more accurate non-invasive assessment.

scholarly journals P457Longitudinal cardiac magnetic resonance assessment in patients with aortic stenosis

2017 ◽  
Vol 38 (suppl_1) ◽  
Author(s):  
R. Everett ◽  
C.W.L. Chin ◽  
J. Kwiencinski ◽  
W.J. Jenkins ◽  
M.A. Clavel ◽  
...  
Keyword(s):  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aortic Stenosis
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