Zweidimensionale Strain-Echokardiographie zur Analyse der regionalen linksventrikulären Funktion bei Aortenklappenvitien vor und nach operativem Aortenklappenersatz

Abstract

In 53 patients scheduled for aortic valve replacement (22 with aortic stenosis (AS), 18 with aortic insufficiency (AI), 13 with aortic stenosis and insufficiency serial echocardiographic studies were performed pre- and postoperatively (within 7 days and at 6 months). Basal, mid and apical parasternal short-axis views were acquired (GE Vivid 7, Horton, Norway). Using a novel computer software (GE Ultrasound, Horton, Norway) which allows automatic frame-by-frame tracking of accoustic markers during the heart cycle radial and circumferential strain and strain rate were defined as parameters of myocardial deformation for each segment in a 16 segment model of the left ventricle.Results: Preoperatively segmental strain and strain rate data were not significantly different between the three aortic pathologies. Immediately postoperatively radial strain increased in the AS group (P<0.001), dropped in the AI group (P<0.001) and remained unchanged in the aortic stenosis and insufficiency group. During the subsequent 6 months follow-up radial strain increased significantly in all three groups. Similar changes were observed for the other strain and strain rate parameters. There was a significant correlation between the reduction in meridonial wall stress after aortic valve replacement for AS and increase in radial strain. Conclusions: Myocardial deformation parameters change significantly soon after aortic valve replacement for aortic stenosis or aortic insufficiency indicating a significant dependency of determined myocardial deformation parameters on left ventricular preload and afterload. During the subsequent 6 months follow-up myocardial deformation increases indicating improvement in myocardial contractility