Sharif Digital Repository

Heart attack is one of the most common causes of death in the world. Coronary artery disease is the most recognized cause of heart attack whose onset and progression have been attributed to low-density lipoprotein (LDL) passing through the wall of the artery. In this paper, hemodynamic variables as well as the concentration of LDL through the coronary porous artery at the Left Anterior Descending coronary artery (LAD), and its first diagonal branch (D1) under the heart motion investigated using computational simulation. The geometry that has been studied in this paper is the first bifurcation of Left Anterior Descending (LAD) that has been placed on a perimeter of hypothetical sphere... 

This study investigated the effects of different patterns of coronary artery tortuosity (CAT) on the stress concentration of the plaques and the blood flow pattern inside an atherosclerotic artery to predict the risk of plaque rupture and progression. Four different loadings of the coronary artery, including pulsatile blood pressure as well as one-end twist around the artery axis at blood pressures of 74, 100, and 120 mmHg were considered. No study has addressed bent and twist buckling of an atherosclerotic artery considering pulsatile flow (for bent buckling), fluid-solid interaction, and different geometrical parameters of the plaque. The results showed that C-shape tortuosity under... 

Fractional flow reserve (FFR)-based decision improves the outcomes of percutaneous coronary intervention (PCI) for some patients, while its effectiveness in improving the results of coronary artery bypass graft (CABG) is unclear, in particular for moderate stenosis. It may be due to the fact that FFR cannot take into account the impacts of competitive flow (CF), intimal hyperplasia (IH), as well as compliance mismatch (CMM). As a result, two questions arise 1) whether FFR is a sufficient factor to decide to perform the CABG for patients with moderate to severe stenosis or not and 2) whether post-operative FFR shows the effectiveness of a graft. To shed light on this matter, two... 

One of the main causes of death the world over are cardiovascular diseases, of which coronary artery disease (CAD) is a major type. This disease occurs when the diameter narrowing of one of the left anterior descending, left circumflex, or right coronary arteries is equal to or greater than 50 percent. Angiography is the principal diagnostic modality for the stenosis of heart vessels; however, because of its complications and costs, researchers are looking for alternative methods such as data mining. This study conducts data mining algorithms on the Z-Alizadeh Sani dataset which has been collected from 303 random visitors to Tehran's Shaheed Rajaei Cardiovascular, Medical and Research... 

Nowadays, cardiovascular diseases are very common and are one of the main causes of death worldwide. One major type of such diseases is the coronary artery disease (CAD). The best and most accurate method for the diagnosis of CAD is angiography, which has significant complications and costs. Researchers are, therefore, seeking novel modalities for CAD diagnosis via data mining methods. To that end, several algorithms and datasets have been developed. However, a few studies have considered the stenosis of each major coronary artery separately. We attempted to achieve a high rate of accuracy in the diagnosis of the stenosis of each major coronary artery. Analytical methods were used to... 

The function and morphology of Endothelial Cells (ECs) play a key role in atherosclerosis. The mechanical stimuli of ECs, such as Wall Shear Stress (WSS) and arterial wall strain, greatly inuence the function and morphology of these cells. The present article deals with computations of these stimuli for a 3D model of a healthy coronary artery bifurcation. The focus of the study is to propose an accurate method for computations of WSS and strains. Two approaches are considered: Coupled simultaneous simulation of arterial wall and blood flow, called fluid-Structure Interaction (FSI) simulation, and decoupled, which simulates each domain (fluid and solid domain) separately. The study... 

Atherosclerosis is a major cause of coronary artery disease leading to morbidity and mortality worldwide. Currently, coronary angiography is considered to be the most accurate technique to diagnose coronary artery disease (CAD). However, this technique is an invasive and expensive procedure with risks of serious complications. Since the symptoms of CAD are not noticed until advanced stages of the disease, early and effective diagnosis of CAD is considered a pertinent measure. In this paper, a non-invasive optical signal, the finger photoplethysmogram (PPG) obtained before and after reactive hyperemia is investigated to discriminate between subjects with different CAD conditions. To this end,... 

Coronary artery disease is the first cause of death across the world. Targeted delivery of therapeutics through controlled release of micro- and nano-particles remains a very capable approach to develop new strategies in treating restenosis and atherosclerotic plaques. In this research, to produce the arterial geometry, an image-processing was done using CT-scan images of a LAD coronary artery. After implementing the finite element mesh, the Fluid-Structure Interaction (FSI) simulation based on physiological boundary conditions was performed. Next, a Lagrangian description of particles dynamics in a non-Newtonian blood flow considering momentum equation of motion for each particle and the... 

Purpose: Cardiac multimodal image fusion can offer an image with various types of information in a single image. Many coronary stenosis, which are anatomically clear, are not functionally significant. The treatment of such kind of stenosis can cause irreversible effects on the patient. Thus, choosing the best treatment planning depend on anatomical and functional information is very beneficial. Methods: An algorithm for the fusion of coronary computed tomography angiography (CCTA) as an anatomical and transthoracic echocardiography (TTE) as a functional modality is presented. CCTA and TTE are temporally registered using manifold learning. A pattern search optimization algorithm, using... 

Coronary artery disease (CAD) causes oscillations in peripheral arteries. Oscillations of the walls of the brachial arteries of 51 patients were recorded [together with the electrocardiogram (ECG)] by an accelerometer at different cuff pressures. By analyzing the energy of the oscillations in the 30-250 Hz band, 16 of 22 patients with CAD and 26 of 29 non-CAD subjects were classified correctly, independent of the ECG, and with no effect of heart murmurs