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Aortic Valve Mechanics
Published in Michel R. Labrosse, Cardiovascular Mechanics, 2018
J. Dallard, M. Boodhwani, M. R. Labrosse
One common AV lesion is aortic insufficiency (AI), also known as aortic regurgitation, in which the valve does not close completely in diastole (EROA > 0), allowing blood to flow in the reverse direction (leak). There are several causes for AI, including, but not limited to, aortic dilatation, congenital abnormality of the valve, and calcification (ACC/AHA, 2006). The blood reflux from the aorta into the left ventricle increases the ventricular workload through pressure and volume overloads (ACC/AHA, 2006; Ketelsen et al., 2010). In turn, these overloads trigger a hypertrophic dilatation of the left ventricle.
Heart Valve Dynamics
Published in Joseph D. Bronzino, Donald R. Peterson, Biomedical Engineering Fundamentals, 2019
Choon Hwai Yap, Erin Spinner, Muralidhar Padala, and Ajit P. Yoganathan
Aortic regurgitation may be caused by valve disease or aortic root anomaly. It is commonly associated with aortic stenosis, rheumatic fever, and ascending aorta dilation as seen in patients with bicuspid aortic valve and Marfan syndrome (Tsifansky et al., 2010). e prolapse or the mal-coaptation of the valve is oen responsible for regurgitation.
How valvular calcification can affect the outcomes of transcatheter aortic valve implantation
Published in Expert Review of Medical Devices, 2020
Stephan Milhorini Pio, Jeroen Bax, Victoria Delgado
Paravalvular aortic regurgitation and conduction disturbances are the most frequent complications. In the Placement of Aortic Transcatheter Valves (PARTNER) trials, moderate-to-severe paravalvular regurgitation was observed in 12% of patients at 30 days and 11% at 1 year in patients not suitable for surgery, and in 12.2% at 30 days and 6.8% at 1 year in patients with high surgical risk [1,2]. A fast learning curve and new generation TAVI prostheses led to a considerable decrease in the incidence of moderate-to-severe paravalvular regurgitation, and in the PARTNER 2 trial (including intermediate-risk patients), this complication was only observed in 3.8% at 30 days and 3.4% at 1 year follow-up [3]. The most frequent conduction disturbances after TAVI are left bundle branch block (LBBB) and high-degree atrioventricular block. The 30-day rate of new-onset LBBB after TAVI is around 27% (ranging from 4% to 57%) and the rate of high-degree atrioventricular block requiring permanent pacemaker implantation is 17% (ranging from 2% to 51%) [6,7]. These rates vary according to the type of prosthesis (balloon or self-expandable), depth of implantation (deeper into the left ventricular outflow tract [LVOT]), and the presence of conduction abnormalities prior to the procedure.
A review of pulmonary autograft external support in the Ross procedure
Published in Expert Review of Medical Devices, 2019
Vincent Chauvette, Marie-Ève Chamberland, Ismail El-Hamamsy
Dilatation of the pulmonary autograft is one of the most feared complication of the Ross procedure. Its occurrence is associated with the development of aortic regurgitation and the need for reoperation. Effort to minimize the risks of pulmonary autograft dilatation should be actively pursued in order to maximize the benefits associated with the Ross procedure. Providing external support to the autograft effectively prevents dilatation. However, it might also hamper aortic root hemodynamics and have deleterious effects on coronary perfusion. The use of prosthetic material might also be concerning for the risk of endocarditis. Temporary external support with the use of bioengineered materials is a promising approach; combining the advantages of early external support with the long-term benefits of normal root hemodynamics. Further research in this field is needed to determine the long-term outcomes of these techniques and to further develop treatments aimed at mitigating the risks of pulmonary autograft dilatation.