Naoko Moriyama

Effect of age on carotid arterial intima-media thickness in childhood.

To investigate relationships between carotid arterial intima-media thickness (IMT) and age in childhood, we performed high-resolution carotid arterial ultrasonography in 60 healthy children (27 boys, 33 girls; age range, 5–14 years) determined by screening to have no dyslipidemia or hypertension. No plaque formation was found, and irregularity of IMT (root mean square roughness of IMT) did not correlate with age. Mean IMT increased in a linear manner with age [IMT in millimeters = (0.009 × age in years) + 0.35] (r = 0.39, P = 0.002). This correlation remained significant after adjustment for gender, parental smoking, systolic and diastolic blood pressure, body mass index, and serum concentrations of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. None of these known cardiovascular disease risk factors in adults had a significant relationship with age-adjusted IMT in children. While circumferential wall stress and diastolic blood pressure were not correlated with age, mean IMT and lumen diameter showed significant positive relationships with circulating blood volume, which was calculated as the function of height and weight. These data suggested that age-dependent physiologic thickening of arterial walls begins in childhood.

The correlation of irregularities in carotid arterial intima-media thickness with coronary artery disease

Abstract. Noninvasive ultrasonographic assessment of carotid artery intima-media thickness (IMT) can improve risk stratification for coronary artery disease (CAD) in certain patients. Several measurements have been used to evaluate carotid atherosclerosis by ultrasonography. Although it has been reported that angiographic arterial irregularities correlate with pathologic changes of atherosclerosis and the occurrence of cardiovascular events, only a few studies have assessed carotid arterial wall irregularity by ultrasonography. The purpose of this study was to evaluate the irregularity of IMT quantitatively, and its association with the presence or absence of CAD. The correlation of maximum and mean IMT values, and IMT irregularity with the presence or absence of CAD, was investigated in 90 patients who had undergone coronary angiography. IMT was measured by manual tracking of the far wall of the common carotid arteries, carotid bulbs, and internal carotid arteries. The IMT irregularity was defined as the root mean square (RMS) difference between each IMT and averaged IMT. Multiple logistic regression analysis, after adjustment for coronary risk factors, indicated that the RMS difference was a more accurate predictor of CAD than were the mean or maximum IMT values. These results indicate that the evaluation of IMT irregularity by ultrasonography is a useful predictor for the presence of coronary atherosclerosis.

The wake of a large vortex is associated with intraventricular filling delay in impaired left ventricles with a pseudonormalized transmitral flow pattern.

Although an intraventricular filling delay has been observed in patients with a psuedonormalized transmitral flow pattern, little is known about the underlying hydrodynamic nature of this phenomenon. Methods: To examine those hydrodynamics, we studied every echocardiographic frame showing ventricular inflow (80 Hz) in the apical long‐axis view and M‐mode image using contrast echocardiography in 29 patients with a psuedonormalized pattern and in 26 normal controls. The velocity of the filling flow front (Vp), the ratio of Vp to E, and the mean radius of the vortices associated with the filling flow were measured. Results: In both groups, vortices were observed at the ridge of the mitral valve during acceleration of the E‐wave. The mean radius of the vortices was greater in the pseudonormalized filling group than that in the control group (8 ± 2 vs 3 ± 1 mm, P < 0.0001). Vp was smaller in the pseudonormalized group than in the control group (36 ± 6 vs 47 ± 6 cm/sec, P = 0.0008). Vp/E was <1 and smaller in the pseudonormalized group than that in the control group (0.46 ± 0.13 vs 0.59 ± 0.07, P = 0.014) and negatively correlated with the mean radius of the vortices (r = 0.54, P < 0.0001). Conclusions: Contrast echocardiography identified uniform flow characteristics with blood in the filling flow front moving in well‐developed vortices and resulting in a left ventricular filling delay in the impaired left ventricle in spite of an increased early transmitral flow velocity.