Pegah Entezari MD, Presenter: Grant, Siemens AG

Susanne Schnell, Abstract Co-Author: Nothing to Disclose

Riti Mahadevia, Abstract Co-Author: Nothing to Disclose

Daniel Rinewalt, Abstract Co-Author: Nothing to Disclose

Bernd Jung, Abstract Co-Author: Nothing to Disclose

Amir Hossein Davarpanahfakhr MD, Abstract Co-Author: Nothing to Disclose

Chris Malaisrie, Abstract Co-Author: Consultant, Edwards Lifesciences Corporation Research Grant, Medtronic, Inc Speakers Bureau, Baxter International Inc

Patrick Lowell McCarthy MD, Abstract Co-Author: Nothing to Disclose

Jeremy Douglas Collins MD, Abstract Co-Author: Nothing to Disclose

James Christopher Carr MD, Abstract Co-Author: Speaker, Lantheus Medical Imaging, Inc

Michael Markl PhD, Abstract Co-Author: Nothing to Disclose

Alex Barker, Abstract Co-Author: Nothing to Disclose

The purpose of this study is to assess the post aortic valve flow dynamics in a cohort with a wide range of aortic valve morphologies.

With IRB approval, 13 subjects were selected for analysis of aortic valve morphology and its effect on aortic flow patterns using a 4D flow MRI (1.5 T Avanto, Siemens, Germany). Patients had aortic valve cusp pathologies ranging from 2 unicuspid (age: 41±3.7,1 female), 7 bicuspid (3 true bicuspid, 2 right-left coronary cusp fusion, and 2 right-non coronary cusp fusion, age: 46±9.2, 4 females), 3 tricuspid (age:29±3, 2 females ), and 1 quadricuspid (age: 45±8, female). Aortic blood flow was measured using ECG and respiration synchronized 4D flow MRI (3-directional velocity encoding, venc = 150cm/s) with full 3D coverage of the entire thoracic aorta. Data analysis included 3D blood flow visualization (EnSight, CEI, USA) and grading of valve-specific aortic out-flow patterns. Peak velocity and position uniformity of aortic out flow (presence of flow jet and flow jet impingement zones) were quantified at three levels: mid ascending aorta (AAo), aortic arch, and the descending aorta (DAo).

All cases had normal systolic function (EF: 60±4.3%). The peak velocity at the AAo was elevated in patients with a unicuspid aortic valve when compared to bicuspid, tricuspid and quadricuspid aortic valves (ANOVA; 3.1 m/s, vs. 1.8 m/s, 1.1 m/s, & 1.5 m/s, P< 0.05). The ratio of peak velocity in AAo vs. DAo was elevated in patients compared with controls (2.1 vs. 0.9, P< 0.05), and was greatest in patients with a unicuspid valve (2.1). Helical flow was clearly evident in all patients (n=10) with no evidence of helicity in controls. Tricuspid valves did not exhibit jet impingement, while there were markedly different jet impingement positions based on valve morphology and leaflet fusion patterns. 

This study provides evidence that an abnormally functioning valve will affect the local hemodynamic environment. This phenomenon is especially of interest given the heterogenic expression of aortopathy in patients with specific valve abnormalities.

Aortic valve cusp morphology significantly alters the ascending aorta hemodynamic environment, which can result in abnormal conditions leading to remodeling of ascending aorta.

Entezari, P, Schnell, S, Mahadevia, R, Rinewalt, D, Jung, B, Davarpanahfakhr, A, Malaisrie, C, McCarthy, P, Collins, J, Carr, J, Markl, M, Barker, A, From Unicuspid to Quadricuspid: Impact of Valve Morphology on Aortic 3D Blood Flow.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12034932.html