Comparison of echocardiography and angiography in determining the cause of severe aortic regurgitation

A possible relation between pressure loading and thickened leaflets of the aortic valve: a model simulation

A much smaller percentage of thickened leaflets of the aortic valve have been found in the right or left coronary leaflet than in the noncoronary leaflet. This study investigated the pressure loading transferring to the leaflets of the aortic valve and their effects on the valvular thickening. A simple ascending aorta model was established, and a simulation was made. The pressure loading in the coronary and noncoronary leaflets then were estimated. The simulation results showed that 5.8% to 17.% percentage of pressure loading to the coronary leaflet may be decreased by the coronary perfusion in diastole. The coronary arteries play an important role on pressures in the sinuses of Valsalva. The smaller pressure loading transferring to the coronary leaflet than that to the noncoronary leaflet is one reasonable explanation related to the thickened leaflets of the aortic valve.

Association of aortic dilation with regurgitant, stenotic and functionally normal bicuspid aortic valves

To determine whether aortic root dilation associated with a bicuspid aortic valve occurs independently of valvular hemodynamic abnormality, aortic root dimensions were measured by two-dimensional echocardiography in 83 adults with a functionally normal (n = 19), mildly regurgitant (n = 26), severely regurgitant (n = 27) or stenotic (n = 11) bicuspid aortic valve and compared with findings in normal subjects matched for age and gender. Aortic root measurements were made at four levels: anulus, sinuses of Valsalva, supraaortic ridge and proximal ascending aorta. Seventy-one percent of patients with a bicuspid aortic valve were men. When compared with control subjects, all hemodynamic subgroups showed a significantly larger aortic root size at three levels: sinuses of Valsalva, supraaortic ridge and proximal ascending aorta (p less than 0.05 to p less than 0.001). The prevalence of aortic root enlargement among all hemodynamic subgroups ranged from 9% to 59% at the level of the anulus, 36% to 78% at the sinuses, 47% to 79% at the supraaortic ridge and 50% to 64% in the ascending aorta. Thus, there is a high prevalence of aortic root enlargement in patients with a bicuspid aortic valve that occurs irrespective of altered hemodynamics or age. These findings support the hypothesis that bicuspid aortic valve and aortic root dilation may reflect a common developmental defect.

Acute aortic regurgitation due to spontaneous rupture of a bicuspid aortic valve: detection by echocardiography

A 42-year-old man was admitted with acute severe aortic regurgitation. There were no signs of a systemic infection. M-mode and two-dimensional echocardiography revealed bicuspid aortic valve and echocardiographic features consistent with aortic leaflet rupture. The diagnosis was confirmed at surgery. This report illustrates that spontaneous rupture of a bicuspid aortic valve should be considered in acute aortic regurgitation without infective endocarditis.

Idiopathic degeneration of the aortic valve: a common cause of isolated aortic regurgitation

To establish the etiology of isolated aortic valvular regurgitation, histologic examination was carried out on 27 consecutive surgically removed aortic valves from patients with aortic regurgitation. In 12 patients, the regurgitation was due to rheumatic or syphilitic valvular disease or a congenital bicuspid aortic valve. In the remaining 15, no etiology was apparent. In the latter group, seven aortic valves were identified by the surgeon as redundant and eight as thickened and retracted. Despite these gross differences, the histologic features of the 15 valves were similar and consisted of increased and disorganized elastic and collagen fibers, with variable quantities of acid mucopolysaccharide and calcium. Although small foci of myxomatous stroma were present, they did not differ substantially from those observed in age-matched competent aortic valves removed at necropsy, nor were they as extensive as described in reports of floppy aortic valves. Idiopathic degeneration was the most common cause of aortic regurgitation, occurring in more than half of the surgically treated patients. An underlying defect in the synthesis of collagen or elastic fibers, similar to that described in mitral valve prolapse, may be an important feature in aortic valve degeneration.