The assessment of athrosclerotic lesions of thoracic aorta and its distensibility in familial hypercholesterolemia by biplane transesophageal echocardiography

The thoracic aorta is one of the portions which are frequently involved in atherosclrotic lesions associated with familial hypercholesterolemia (FH). We assessed atheroschlerotic lesione of he thoracic aorta and its dynamic compliance in 13 patients with FH (50±10ys) and age-matched 21 normalcontrol subjects by diplane two-demensional (2-D) transesophageal echocardiography (TEE : 5MHz). The dexcending aorta was divided into 4 portions with equal longitudinal length, and degree of atherosclerotic lesions of descending aorta was classified into 4 categories by diplane 2=D echogram according to the severities of atherosclerotic lesions : Sclerotic Score (SS)-1＝intimal thickening, 2＝athermatous plaque, 3＝clacified plaque associated with acoustic shadowing behind the lesion. Scoring of atherosclwrotic lesion of the descending aorta was dne. In all patients with FH, atheroscerotic lesions of SS-1 was observed particularly in the aortic arch was dne. In all patients with FH patients (54%), atherosclerotic lesions greater than SS-3 were found frequently in the aortic arch and descending aorta rather than in the ascending aorta. Total sclerotic scores from each protion were significantly higher in FH (3.8±1.5) than control subjects. We also measured instantanwous dimensional changes of desending aorta in a cardiac cycle by transesophageal M-mode echography with monitoring 2=D view. Compliance index (ΔD/ΔP : maximum dimension-minimum dimension/pluse pressure : mmHg) in FH (0.021±0.008) was less than control subjects (0.043±0.010, p＜0.001) without significant differences of the minimum dimension (at end-diastole) from control subjects. In both control subjects and FH, ΔD/ΔP was correlated with age (r＝－0.84, p＜0.001, r＝－0.73、p＜0.01, respectively). In FH, total scerotic score or ΔD/ΔP was correlated well with total cholesterol level (r＝o.58, p＜0.05, r＝－0.63, p＜0.05, respectively). Thus, TEE with diplane probe was a reliable approach for the evaluation of the wall property of the thoracic aorta. Even in relatively younger population of FH, incidence of atherosclerotic lesions in the thoracic aorta was significantly higher than control subjects, accompanied by reduced aortic compliance.