Echocardiography
Echocardiographic examinations were performed by one experienced physician. The diameter of the cardiac chambers was expressed as the maximum value of the anteroposterior diameter in cardiac cycles. The diameter of the ascending aorta was approximately 4 cm greater than that of the aortic valve during diastole. The thicknesses of the interventricular septum (IVS) and ventricular wall were determined during diastole. Aside from the maximum thickness, the representative thickness of the IVS, which is usually the thickness of the point 25 mm under the right coronary sinus nadir, was also recorded to indicate the overall thickness. The LVOT gradient was calculated using the simplified Bernoulli equation. The ventricular ejection fraction measurements were determined according to the American Society of Echocardiography recommendations. These methods have been provided in greater detail in our previous publication.8