Acute Improvement in Myocardial Function Assessed by Myocardial Strain and Strain Rate After Aortic Valve Replacement for Aortic Stenosis

Abstract

We investigated whether Doppler tissue imaging (tissue velocity, strain, and strain rate) could be useful to detect subtle left ventricular (LV) dysfunction in patients with aortic stenosis and changes in regional myocardial function after aortic valve replacement (AVR). We studied 34 patients (age 69.2 +/- 10.4 years) with severe aortic stenosis, 21 of whom underwent AVR. Tissue velocity, systolic strain, strain rate, time to peak strain, and time to peak systolic and diastolic strain rates of basal and midsegments were measured in the apical 4-, 3-, and 2-chamber views before and 2 weeks after AVR. Strain and systolic strain rate showed the best correlation with LV ejection fraction (r = 0.80 and r = 0.70, respectively, both P < .0001). Early and late diastolic strain rates showed significant correlations with LV mass index (r = 0.45, P < .01; and r = 0.64, P < .0001, respectively) and time to peak strain, to peak systolic strain rate, and to peak early diastolic strain rate with aortic pressure gradient (r = 0.45, P < .01; r = 0.44, P < .01; and r = 0.56, P < .001, respectively) before AVR. Although LV mass index and LV systolic function did not change significantly after 2 weeks (LV mass index, 137 +/- 54 vs 125 +/- 36 g/m2; LV ejection fraction, 60 vs 58%, both P = not significant), peak strain and strain rates increased (P < .001) and time to peak strain and strain rate shortened after AVR (P < .001). Tissue velocities did not change significantly after AVR. Strain and strain rate parameters seemed to relate to LV function and aortic stenosis severity. Further, they seemed to be superior to tissue velocity and conventional echocardiography in detecting subtle changes in myocardial function after AVR before LV mass and LV function showed improvement.