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BACKGROUND The downward movement of the aortic root during the cardiac cycle may be responsible for producing the circumferential tear observed in aortic dissections. METHODS AND RESULTS Contrast injections were investigated in 40 cardiac patients, and a finite element model of the aortic root, arch, and branches of the arch was built to assess the(More)
BACKGROUND The study was intended to investigate the reason why congenitally bicuspid valves (CBAVs), which may function hemodynamically and clinically well, have a high early failure rate. METHODS Observations were made on cryopreserved, then thawed human aortic roots containing CBAVs. Valvular function was studied in the left heart simulator using(More)
BACKGROUND AND AIM OF THE STUDY In some patients with dilated aortic root, attempts have been made to replace the aorta and preserve the anatomically normal leaflets. The tubular Dacron graft used in the valve-sparing procedure does not have the sinuses of Valsalva, and therefore might adversely affect the valve. The effect of the presence or absence of the(More)
Two hundred twenty-one aortic cusps from 96 patients who underwent aortic valve replacement were examined. Of all the cusps that showed any calcific deposits, 87% had calcific deposits in 1 of 2 specific patterns: a coaptation pattern, where calcific deposits occurred along the line of cusp coaptation, and a radial pattern, where calcific deposits occurred(More)
Calcification of bioprostheses used for heart valve replacement is a serious problem, since it causes bioprosthetic dysfunction. In vivo, bioprostheses are subjected to large mechanical stresses during each cardiac cycle. We investigated whether stresses play a major role in calcification of bioprostheses. Previous studies of Carpentier-Edwards porcine,(More)
AIM Our goal is to understand how a mural thrombus may influence the pressure transmitted to and the dilation experienced by the abdominal aortic aneurysm (AAA) wall. METHODS Two intact AAAs with mural thrombus were removed from patients and pressurized to 100 mmHg. The pressure was measured using a micro-tip needle transducer inserted in the aneurysm(More)
In aortic dissection intimal tear develops in a transverse direction. Since dissection is associated with the aneurysm of the aorta, its mechanism was investigated by analysing the pressure induced wall stress as a function of 'growth' of the aneurysm. The stresses were determined using a finite element analysis where the aorta was modelled as an isotropic,(More)
OBJECTIVE The study was aimed at determining which cardiac pathologies are associated with increased longitudinal stress in the aorta and therefore may be responsible for the intimal transverse tears seen in aortic dissections. METHODS Aortic root contrast injections were analyzed in 90 cardiac patients to measure the downward motion of the annulus during(More)
The design parameters of the natural aortic valve in vivo were not known, which may explain why various bioprosthetic valves have been designed differently. The design of the aortic valve was studied in vivo by placing radiopaque markers in the valve. The marker movement revealed that, during a cardiac cycle, the design parameters of the valve were changing(More)
To estimate when an abdominal aortic aneurysm (AAA) may rupture, it is necessary to understand the forces responsible for this event. We investigated the wall stresses in an AAA in a clinical model. Using CT scans of the AAA, the diameter and wall thickness were measured and the model of the aneurysm was created. The wall stresses were determined using a(More)