Total cholesterol content of erythrocyte membranes and coronary atherosclerosis: an intravascular ultrasound pilot study.

Background: Increasing evidence suggests that erythrocytes may participate in atherogenesis. We sought to investigate the relationship between total cholesterol content in erythrocyte membranes (CEM) and coronary atheroma burden in patients with coronary artery disease (CAD).

Methods: We prospectively enrolled 28 participants: 11 patients with angiographically significant CAD and 17 controls.

Low-Density Lipoprotein concentration in the normal Left Coronary Artery tree.

Background: The blood flow and transportation of molecules in the cardiovascular system plays a crucial role in the genesis and progression of atherosclerosis. This computational study elucidates the Low Density Lipoprotein (LDL) site concentration in the entire normal human 3D tree of the LCA.

Methods: A 3D geometry model of the normal human LCA tree is constructed.

Sex-related differences in the angiographic results of 14,500 cases referred for suspected coronary artery disease.

Objective: To investigate sex differences of angiographic results in patients undergoing coronary angiography for suspected coronary artery disease (CAD).

Methods: We retrospectively assessed the coronary angiograms of 2840 women and 11,610 men from 1984 to 2003. We examined sex differences regarding the extent and topography of significant stenoses (SS) (i.

In vivo comparative study of linear versus geometrically correct three-dimensional reconstruction of coronary arteries.

Although conventional linear 3-dimensional (3D) reconstruction of coronary arteries by intravascular ultrasound has been widely used for the assessment of plaque volume and progression; the volumetric error (VE) that is produced has not been adequately studied. Linear and geometrically correct 3D reconstruction was applied in 16 coronary arterial segments from 9 patients. Using geometrically correct reconstruction as reference, VE was assessed in 1-mm-long arterial slices.

Elevated heart rate and atherosclerosis: an overview of the pathogenetic mechanisms.

Several epidemiological studies have reported that an elevated heart rate is associated with coronary atherosclerosis independently of other risk factors. In this review we explore the pathophysiologic mechanisms involved in the pro-atherosclerotic effect of elevated heart rate, apart from its association with sympathetic tone. An elevated heart rate enhances the magnitude and frequency of the tensile stress imposed on the arterial wall and prolongs the exposure of coronary endothelium to the systolic low and oscillatory shear stress.

Non-Newtonian models for molecular viscosity and wall shear stress in a 3D reconstructed human left coronary artery.

The capabilities and limitations of various molecular viscosity models, in the left coronary arterial tree, were analyzed via: molecular viscosity, local and global non-Newtonian importance factors, wall shear stress (WSS) and wall shear stress gradient (WSSG). The vessel geometry was acquired using geometrically correct 3D intravascular ultrasound (3D IVUS). Seven non-Newtonian molecular viscosity models, plus the Newtonian one, were compared.

A novel active contour model for fully automated segmentation of intravascular ultrasound images: in vivo validation in human coronary arteries.

The detection of lumen and media-adventitia borders in intravascular ultrasound (IVUS) images constitutes a necessary step for the quantitative assessment of atherosclerotic lesions. To date, most of the segmentation methods reported are either manual, or semi-automated, requiring user interaction at some extent, which increases the analysis time and detection errors. In this work, a fully automated approach for lumen and media-adventitia border detection is presented based on an active contour model, the initialization of which is performed via an analysis mechanism that takes advantage of the inherent morphologic characteristics of IVUS images.

Prevalence of narrowing >or=50% of the left main coronary artery among 17,300 patients having coronary angiography.

We sought to investigate the prevalence of left main coronary artery significant stenosis (LMSS) (>or=50% of the luminal diameter) in an angiographic series of patients, to describe the associated coronary stenoses, and to assess the influence of age and gender on these findings. The angiograms of 17,323 consecutive patients from January 1, 1984 to December 31, 2003 were retrospectively analyzed. LMSS was found in 823 patients (4.

Flow parameters in normal left coronary artery tree. Implication to atherogenesis.

The dominant haemodynamic flow parameters of wall pressure (WP), wall shear stress (WSS), molecular viscosity and the spatial gradients: wall pressure gradient (WPG) and wall shear stress gradient (WSSG) along the normal human left coronary artery (LCA) tree are numerically analyzed in relation to atheronegenesis. The LCA tree includes the left main coronary artery, the left anterior descending branch, the left circumflex branch and their major branches. Spatial differentiation indicates that low values of WP (locally), WPG, WSS, WSSG and high molecular viscosity appear opposite flow dividers and this probably correlates to atherosclerosis localization.

Is left coronary system more susceptible to atherosclerosis than right? A pathophysiological insight.

On the basis of pathological, angiographical, intravascular ultrasound and computed tomography data coronary atherosclerosis appears to be more prevalent in the left coronary arterial system compared to the right. However, the pathophysiological mechanisms implicated in this discrepancy largely remain uncertain. The hemodynamic or anatomical differences between the right and left coronary artery might play a key role.

In-vivo accuracy of geometrically correct three-dimensional reconstruction of human coronary arteries: is it influenced by certain parameters?

Objective: The geometrically correct three-dimensional reconstruction of human coronary arteries by integrating intravascular ultrasound (IVUS) and biplane angiography constitutes a promising imaging method for coronaries with broad clinical potential. The determinants of the accuracy of the method, however, have not been investigated before.

Methods: In total, 17 arterial segments (right coronary artery, n=7; left anterior descending, n=4; left circumflex, n=6) derived from nine patients were three-dimensionally reconstructed by applying three-dimensional intravascular ultrasound.

In-vivo validation of spatially correct three-dimensional reconstruction of human coronary arteries by integrating intravascular ultrasound and biplane angiography.

Objectives: The in-vivo validation of geometrically correct three-dimensional reconstruction of human coronary arteries by integrating intravascular ultrasound and biplane coronary angiography has not been adequately investigated. The purpose of this study was to describe the reconstruction method and investigate its in-vivo feasibility and accuracy.

Methods: In 17 coronary arteries (mean length, 85.

Prevalence of ectasia in human coronary arteries in patients in northern Greece referred for coronary angiography.

We determined the prevalence of coronary artery ectasia (CAE) in patients who were referred to our institution for coronary angiography for any reason and investigated its potential association with angiographically significant coronary artery disease (CAD). We also examined whether CAE and CAD are topographically associated. In 10,524 consecutive patients from January 1, 1995 to December 31, 2003, the corresponding coronary angiographies were analyzed and cases of CAE were identified, recorded, and summarized.

Spatial and phasic oscillation of non-Newtonian wall shear stress in human left coronary artery bifurcation: an insight to atherogenesis.

Objective: To investigate the wall shear stress oscillation in a normal human left coronary artery bifurcation computational model by applying non-Newtonian blood properties and phasic flow.

Methods: The three-dimensional geometry of the investigated model included the left main coronary artery along with its two main branches, namely the left anterior descending and the left circumflex artery. For the computational analyses a pulsatile non-Newtonian flow was applied.

Molecular viscosity in the normal left coronary arterial tree. Is it related to atherosclerosis?

The purpose of this study is to elucidate, probably for the first time, the distribution of molecular viscosity in the entire left coronary artery (LCA) tree. The governing mass, momentum, and energy flow equations were solved by using a previously validated 3-dimensional numerical (finite-element analysis) code. High-molecular-viscosity regions occur at bifurcations in regions opposite the flow dividers, which are anatomic sites predisposed for atherosclerotic development.

Wall pressure gradient in normal left coronary artery tree.

The three-dimensional wall pressure gradient (WPG) of the normal human left coronary artery (LCA) tree is quantitatively analysed. A model LCA tree, based on averaged human data set extracted from angiographies was adopted for finite-element analysis. The LCA tree includes the left main coronary artery (LMCA), the left anterior descending (LAD), the left circumflex artery (LCxA) and their major branches.