Velocity Vector Imaging in Patients With Moderate-to-Severe Aortic Regurgitation
Velocity Vector Imaging in Patients With Moderate-to-Severe Aortic Regurgitation
Velocity Vector Imaging may provide reliable and detailed information on left ventricular segmental function in asymptomatic patients with moderate-to severe AR. This may help to identify subclinical myocardial dysfunction in order to operate early enough to prevent postoperative heart failure and restrict unnecessary early operation which could be associated with operative risks and mortality related to prosthetic valves.
Chronic aortic regurgitation (AR) is a progressive process which causes both left ventricular volume and pressure overload. While the volume overload is associated with the degree of the aortic regurgitant volume, the pressure overload occurs as a result of systemic hypertension developed due to increased stroke volume. In early stages, excentric hypertrophy occurs aiming to compensate the volume overload in the left ventricle. Therefore , ejection fraction remains in normal range despite the increasing volume overload. Left ventricular dilatation and impairment in ejection fraction only occur in the end stages of the disease. Asymptomatic patients with chronic aortic regurgitation (AR) have a good prognosis in the presence of preserved systolic function. Therefore it is a challenge to identify patients with subclinical left ventricular (LV) dysfunction. Velocity vector imaging (VVI) is a new echocardiographic method based on two dimensional gray scale imaging, which is angle independent and can provide more accurate data about cardiac function.
Inclusion Criteria:
Exclusion Criteria: