The objectives of this investigation were to evaluate biomechanical factors in the atherosclerotic process using human in vivo hemodynamic parameters and computed numerical simulation qualitatively and quantitatively. The three-dimensional spatial patterns of steady and pulsatile flows in the left coronary artery were simulated, using a finite volume method. Coronary angiogram and Doppler ultrasound measurement of the proximal left coronary flow velocity were performed in humans. Inlet wave velocity distribution obtained from in vivo data of the intravascular Doppler study allowed for input of in vitro numerical simulation. Hemodynamic variables, such as flow velocity, pressure and shear stress of the left anterior descending coronary bifurcation site were calculated. We found that there were spatial fluctuation of flow-velocity and recirculation areas at the curved outer wall of the left anterior descending coronary artery, which were due to the differences of flow-velocity and shear stress, especially during the declaration phase of pulsatile flow. This study suggests that rheologic properties may be a part of the atherogenic process in the coronary bifurcated and curved areas.
Biomechanics ; Blood Flow Velocity/physiology ; Blood Pressure/physiology ; Coronary Arteriosclerosis/physiopathology* ; Coronary Arteriosclerosis/etiology* ; Coronary Vessels/physiopathology* ; Hemodynamics/physiology* ; Homeostasis/physiology ; Human ; Models, Cardiovascular* ; Pulsatile Flow ; Stress, Mechanical

Endothelial function plays a very important role in the process of erection. Erectile dysfunction (ED) and coronary artery disease (CAD) overlap in risk factors, aetiology and clinical outcomes. Endothelial dysfunction is considered to be their shared aetiological factor. There is growing evidence that patients presenting with ED should be investigated for CAD, even if with no symptoms of the problem. Earlier diagnosis of ED can facilitate prompt intervention, reduce long-term complications, especially the risk of CAD, and provide effective treatment for ED.
Arteriosclerosis ; physiopathology ; Coronary Artery Disease ; physiopathology ; Endothelium, Vascular ; physiology ; physiopathology ; Erectile Dysfunction ; physiopathology ; Humans ; Male ; Penis ; blood supply ; physiopathology

Arteriosclerosis ; physiopathology ; Blood Pressure ; physiology ; Cardiovascular Diseases ; physiopathology ; Coronary Disease ; physiopathology ; Humans ; Hypertension ; physiopathology ; Predictive Value of Tests ; Pulse

Insulin resistance is an important risk factor for coronary artery disease. However, there has been no data regarding its clinical effect on the outcomes of percutaneous coronary intervention (PCI) in non-diabetic patients. We analyzed 98 non-diabetic consecutive patients (59+/-11.5 yr, male:female=63:35) who underwent elective coronary angiography. The patients were divided into two groups: Group I (n=71; the value of HOMA-IR [homeostasis model assessment of insulin resistance] <2.6) and Group II (n=27; the value of HOMA-IR > or = 2.6). In-hospital and 30-day major adverse cardiac events (MACE) were compared between the two groups. The concentrations of fasting insulin and triglyceride were significantly higher in Group II than in Group I. Significant correlations were observed between the value of HOMA-IR and body mass index (r=0.489, p<0.001), levels of total cholesterol (r=0.204, p=0.045), triglyceride (r=0.334, p=0.001) and apolipoprotein B (r=0.212, p=0.038). PCI was performed in 59 patients (60.2%). In-hospital and 30-day MACE were higher in Group II than Group I (2.4% vs. 27.8%, p=0.008; 2.4% vs. 27.8%, p=0.008). Multivariate analysis revealed that the value of HOMA-IR > or = 2.6 was an independent predictor of MACE. Increased HOMA-IR level is an important prognostic indicator in non-diabetic patients underwent PCI.
Prognosis ; Models, Biological ; Middle Aged ; Male ; *Insulin Resistance ; Humans ; Homeostasis ; Female ; Coronary Stenosis/blood/physiopathology/therapy ; Coronary Arteriosclerosis/blood/physiopathology/therapy ; *Angioplasty, Transluminal, Percutaneous Coronary/adverse effects ; Aged

The objective of the present study was to evaluate the hemodynamic characteristics of an atherosclerosis-prone coronary artery compared to the aorta. We describe three- dimensional spatial patterns of wall shear stress (WSS) according to the impedance phase angle in pulsatile coronary and aorta models using in vivo hemodynamic parameters and computed numerical simulations both qualitatively and quantitatively. Angiography of coronary arteries and aortas were done to obtain a standard model of vascular geometry. Simultaneously to the physiologic studies, flow-velocity and pressure profiles from in vivo data of the intravascular Doppler and pressure wire studies allowed us to include in vitro numerical simulations. Hemodynamic variables, such as flow-velocity, pressure and WSS in the coronary and aorta models were calculated taking into account the effects of vessel compliance and phase angle between pressure and flow waveforms. We found that there were spatial fluctuations of WSS and in the recirculation areas at the curved outer wall surface of the coronary artery. The mean WSS of the calculated negative phase angle increased in the coronary artery model over that in the aorta model and the phase angle effect was most prominent on the calculated amplitude of WSS of the coronary artery. This study suggests that the rheologic property of coronary circulation, such as the fluctuation of WSS/WSR induces several hemodynamic characteristics. A separation of flow-velocity, a difference in phase between pressure conductance and blood flow and prominent temporal and/or spatial oscillatory fluctuations of the shear forces as a function of pulsatile flow might be important factors in atherogenesis and progression of atherosclerosis.
Adult ; Aged ; Aorta, Abdominal/*physiology ; Arteriosclerosis/etiology/*physiopathology ; Coronary Circulation ; Coronary Vessels/*physiology ; Electric Impedance ; Female ; *Hemodynamics ; Human ; Male ; Middle Age ; Stress, Mechanical