NONINVASIVE ULTRASOUND EVALUATION OF PRESSURE-GRADIENTS IN AORTIC ROOT OF HOMOZYGOTES FOR FAMILIAL HYPERCHOLESTEROLEMIA

The aim of this study was to measure noninvasively by Doppler ultrasound the blood flow velocity at the level of the aortic root in patients with homozygous familial hypercholesterolemia (FH) to detect abnormal pressure gradients. Seven patients with homozygous FH and seven healthy controls matched for age and sex were included in the study. Continuous-wave Doppler (2 MHz) was used to measure the highest detectable velocity from the aortic root; the probe was positioned in the suprasternal notch. When an abnormal velocity was detected, the corresponding pressure drop was calculated from the formula: Delta P=4Vmax2. Each FH patient had an abnormal aortic velocity consistent with a pressure gradient across the valvular area. All the controls had normal aortic velocities (p<0.01). The measurement of the pressure drop across the aortic valvular area in FH patients gives an estimate of the lesions produced by cholesterol deposition in a crucial area of the cardiovascular system near the origin of coronary arteries. The noninvasivity of this method makes it an excellent method for obtaining parameters for follow-up and clinical trials.