Arterial distensibility as a possible compensatory mechanism in chronic aortic regurgitation

Abstract

Objective -To evaluate elastic properties of conduit arteries in asymptomatic patients who have severe chronic aortic regurgitation. Methods -The elastic properties of great arteries determine the pulsatile component of afterload and influence the performance of the left ventricle [1][2][3][4] , especially when ventricular dysfunction is present 5,6 . The importance of the great arteries in absorbing the impact of the oscillations caused by the alternating function of the heart must be particularly highlighted in patients with aortic regurgitation, in which a very large stroke volume is ejected into the proximal aorta at each systole.Dilation occurs during the development of chronic aortic regurgitation, and, later, left ventricular dysfunction occurs associated with symptoms and the worsening of the prognosis 7 . Several factors are involved in the maintenance of left ventricular function in chronic aortic regurgitation, and the role of afterload is little known in this process.The objective of the present study is to evaluate the elastic properties of great arteries in asymptomatic patients with severe chronic aortic regurgitation and preserved left ventricular function. MethodsFourteen patients with severe isolated aortic regurgitation were studied, the mean age was 29±2 years, and 11 were men and 3 were women. Patients did not have clinical symptoms of congestive cardiac regurgitation (functional class I, NYHA). The cause of valvular dysfunction was rheumatic fever in all cases. The mean ejection fraction of the left ventricle, assessed through radioisotope ventriculography, was 0.61±0.02. Echodopplercardiography was performed in patients prior to the study. All patients had sinus rhythm on echocardiography at the time the examination was performed, and they were not taking medication before or after its performance.The control group included 12 healthy volunteers who had no history of previous cardiovascular or systemic disease. The mean age was 30±1 years, 11 were men, and one was a woman.Informed consent was obtained from all participants prior to the beginning of the study, according to the Ethics

Aortic Stiffness

“…Patients with chronic aortic regurgitation and preserved systolic function have increased arterial distensibility. This could be due to greater vascular compliance needed as a compensatory mechanism to lessen the impact of the large systolic volume ejected into conduit arteries (45). The lack of this "compensatory distensibility" seems to be associated with faster hemodynamic deterioration and disease progression (46).…”

Atherosclerosis masks Hill's sign in severe chronic aortic regurgitation

“…Another study found patients with chronic AR to have increased carotid arterial distensibility. 12 Although retrospective and small, this study found in patients with severe chronic AR that the SBPG is decreased in the presence of CAD and with more marked aortic atherosclerosis. This lowers the diagnostic utility of this finding.…”

Μελέτη Των Χαρακτηριστικών Του Σφυγμικού Κύματος Και Άλλων Αιμοδυναμικών Παραμέτρων Του Καρδιαγγειακού Συστήματος Στην Απόφραξη Της Υπονεφρικής Κοιλιακής Αορτής

“…Οι μεταβολές αυτές είναι πιθανό να έχουν και γενετικό υπόβαθρο, καθώς η διγλώχινα αορτική βαλβίδα μεταβιβάζεται κατά τον αυτοσωμικό κυρίαρχο τύπο220 . Αυξημένη αορτική δυσκαμψία παρατηρείται και σε παιδιά μετά την χειρουργική διόρθωση τετραλογίας Fallot και φαίνεται πως σχετίζεται με την προοδευτική διάταση της αορτικής ρίζας που παρατηρείται221 222. .…”