2.3. Assessment of aortic strain
Aortic root, AoS and AoD was measured by 2D motion mode (M-mode)
transthoracic echocardiography at a level of 3–4 cm above the aortic
valve from a transthoracic parasternal long-axis view, at the time of
maximum aortic anterior motion, and at the peak of the QRS complex at
the simultaneous electrocardiogram recording, respectively. The
percentage change in the aortic root was calculated as DAo% = 100 ×
(AoS ˗ AoD) / AoD to obtain aortic strain (9).