New insights in the pathophysiology of mitral and aortic regurgitation in pediatric age: role of angiotensin-converting enzyme inhibitor therapy.

This review has been focused on the new insights in the pathophysiology of mitral and aortic regurgitation and on the role of ACE-inhibitor therapy in children with chronic volume overload due to left-sided valvular lesions. Recent clinical studies show that these drugs have favorable effects when administered orally in chronic mitral and aortic regurgitation. Interestingly, the beneficial effects of ACE-inhibition regard the basic anatomic, hemodynamic and adaptive pathologic conditions related to volume overload, namely, the regurgitant orifice area and volume and ventricular remodeling. The heart is a plastic structure, constantly being altered in size, shape and composition in response to chronic volume overload. Thus, modulation of cardiac plasticity by ACE-inhibition raises the possibility of using new therapeutic strategies specifically designed to prevent and/or antagonize the mechanical disadvantages secondary to volume overload-induced cardiac remodeling. The beneficial effects of ACE-inhibition have also been observed in growing children with asymptomatic valvular regurgitation; thus, it appears that the unloading therapy has the potential of influencing the natural history of both mitral and aortic regurgitation and possibly delays surgical valve repair or replacement. These data justify early inhibition of the renin-angiotensin system in children with left ventricular volume overload due to mitral and aortic regurgitation.