**Introduction**

**Chapter 1**

**Provisional chapter**

**Focus on Coronary Atherosclerosis**

**Focus on Coronary Atherosclerosis**

DOI: 10.5772/intechopen.77301

Atherosclerosis is a vascular disorder consisting of thickening of arteries and lack of elasticity. Result of atherosclerosis is that arteries become narrowed and hardened due to an excessive buildup of plaque around the artery wall. The disease disrupts the flow of blood around the body, posing serious cardiovascular complications. Arteries contain what is called an endothelium, a thin layer of cells that keeps the artery smooth and allows blood to flow easily. Endothelial damage starts the first step of atherosclerosis. After this, lowdensity lipoprotein (LDL) cholesterol accumulates in the artery wall. Inflammatory process starts after this accumulation, and macrophages reach the endothelium to clean up cholesterol. But some macrophages are stuck in the affected part of the artery wall in this process. Over time, this results in plaque being built up, consisting of cholesterol and macrophage white blood cells. The plaque clogs up the artery, disrupting the flow of blood. This potentially causes blood clots that can result in life-threatening conditions such as heart attack and other cardiovascular diseases. Atherosclerosis can be seen in all arteries in the body. Atherosclerosis is the most common cause of death in the western countries. Some risk factors are as follows: age, sex, familial predisposition, hyperlipidemia, hypertension, diabetes mellitus, smoking, obesity, insufficient physical activity, etc. Whatever the main reason or the risk factor is, once atherosclerosis is formed, several

life-threatening cardiovascular disorders can be seen. So, it has to be revealed.

**Keywords:** atherosclerosis, coronary atherosclerosis, coronary artery disease, ischemic

Atherosclerosis locution originates from the Greek-Latin word "atera" meaning "oat or milky mush." It describes a vascular disorder consisting of thickening of arteries and lack of elastic-

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Hakan Saçlı, İbrahim Kara and Mehmet Kaan Kırali

Hakan Saçlı, İbrahim Kara and Mehmet Kaan Kırali

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.77301

**Abstract**

heart disease

ity. The general pathology refers to three situations:

**1. Introduction**

#### **Focus on Coronary Atherosclerosis Focus on Coronary Atherosclerosis**

Hakan Saçlı, İbrahim Kara and Mehmet Kaan Kırali Hakan Saçlı, İbrahim Kara and Mehmet Kaan Kırali

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.77301

#### **Abstract**

Atherosclerosis is a vascular disorder consisting of thickening of arteries and lack of elasticity. Result of atherosclerosis is that arteries become narrowed and hardened due to an excessive buildup of plaque around the artery wall. The disease disrupts the flow of blood around the body, posing serious cardiovascular complications. Arteries contain what is called an endothelium, a thin layer of cells that keeps the artery smooth and allows blood to flow easily. Endothelial damage starts the first step of atherosclerosis. After this, lowdensity lipoprotein (LDL) cholesterol accumulates in the artery wall. Inflammatory process starts after this accumulation, and macrophages reach the endothelium to clean up cholesterol. But some macrophages are stuck in the affected part of the artery wall in this process. Over time, this results in plaque being built up, consisting of cholesterol and macrophage white blood cells. The plaque clogs up the artery, disrupting the flow of blood. This potentially causes blood clots that can result in life-threatening conditions such as heart attack and other cardiovascular diseases. Atherosclerosis can be seen in all arteries in the body. Atherosclerosis is the most common cause of death in the western countries. Some risk factors are as follows: age, sex, familial predisposition, hyperlipidemia, hypertension, diabetes mellitus, smoking, obesity, insufficient physical activity, etc. Whatever the main reason or the risk factor is, once atherosclerosis is formed, several life-threatening cardiovascular disorders can be seen. So, it has to be revealed.

DOI: 10.5772/intechopen.77301

**Keywords:** atherosclerosis, coronary atherosclerosis, coronary artery disease, ischemic heart disease

## **1. Introduction**

Atherosclerosis locution originates from the Greek-Latin word "atera" meaning "oat or milky mush." It describes a vascular disorder consisting of thickening of arteries and lack of elasticity. The general pathology refers to three situations:

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The predominant type is often seen with intimal fatty plaque formation including central lipid-rich core. We want to mention about this type of atherosclerosis.

under high pressure to the tissues. The arterioles are the last small branches of the arterial system. And, the capillaries are where the exchange of fluid, electrolytes, nutrients, hormones, and other substances occurs. And, of course veins, venules, collect blood from the capillaries.

Focus on Coronary Atherosclerosis

5

http://dx.doi.org/10.5772/intechopen.77301

We have to learn the normal state before discussing the pathological status. The normal artery wall is consisting of intima, media, and adventitia. Lumen is lined by a monolayer of endothelial cells that overlies smooth muscle cells. The inner layer of smooth muscle cells, known as the intima, is circumscribed by the internal elastic lamina. The media layer is between the internal elastic lamina and external elastic lamina. The media is another layer of smooth muscle cells. Outside the external elastic lamina is an adventitia part that is rarely populated

Atherosclerosis is a progressive disease of medium- and large-sized arteries characterized by focal intimal lesions called atheromas or atherosclerotic plaques that protrude into vessel lumen and eventually leading to various complications [2]. There are several diseases led by atherosclerosis: coronary artery disease, peripheral artery disease, and carotid artery disease.

Atherosclerosis is a chronic, inflammatory, fibroproliferative disease of medium- and largesized arteries [3]. There are different stages to form the atherosclerotic plaque. The initiation phase is the beginning and the progression of the plaque and the final complication stage.

Chronic or recurrent endothelial damage is the cornerstone of the "response to damage" hypothesis. Hyperlipidemia, hypertension, smoking, immunoreactions, hemodynamic factors, toxins, and viruses can cause this chronic endothelial damage. Hemodynamic deformities such as endothelial shear stress, turbulent flow, or unfavorable effects of hypercholesterolemia have a role in the initiation phase. Due to endothelial damage and turbulent flow, endothelial permeability, cell regeneration, and receptor-mediated LDL endocytosis and leukocyte

Hyperlipidemia has an important role in the atherogenesis [4]. Chronic hyperlipidemia especially hypercholesterolemia can start the endothelial damage. After all, lipoproteins accumulate in these damaged endothelial sites. The cellular response after endothelial damage continues with increased permeability, leukocyte adhesion, monocyte migration, and increased adhesion. This is no longer the initiation phase after this stage; progression has

Some cellular events take an important part in this phase. Smooth muscles migrate from the media layer to intima and macrophages activated. Monocytes turn to macrophages. Activated macrophages, and smooth muscle cells absorb lipids. Modified lipid molecules due to the oxidative mechanisms of modified LDL arise. Oxide LDL makes some additive affects, in order; (a) with the help of altered receptors LDL absorbed easily by macrophages (b) they

These are real threats for mortality and morbidity in the developed countries.

Our main subject is atherosclerosis of arterial vessels.

by cells and microvessels of the vasa vasorum.

**3. Pathophysiology**

adhesion to endothelium increase.

started.

The second morphologic type of atherosclerosis, Mönckeberg's medial calcific sclerosis, is seen in the muscular arteries with a medial calcification. This form is not prominent as classic atherosclerosis and mostly seen after the age of 50. This can be seen radiologically and can be felt with palpation.

The third type is the disorders of the small arteries and arterioles, named arteriosclerosis. This is seen mostly with hypertensive and diabetic patients. This refers to stiffening or hardening of the artery walls.

The final result of atherosclerosis is that arteries become narrowed and hardened due to an excessive buildup of plaque around the artery wall. The disease disrupts the flow of blood around the body, posing serious cardiovascular complications.

Atherosclerosis can be seen in all arteries in the body. But we will instruct about the coronary atherosclerosis. Atherosclerosis is the most common cause of death in the western countries [1].

Arteries contain what is called an endothelium, a thin layer of cells that keeps the artery smooth and allows blood to flow easily. Endothelial damage starts the first step of atherosclerosis. After this LDL cholesterol accumulates in the artery wall. Inflammatory process starts after this accumulation, and macrophages reach the endothelium to clean up cholesterol. But some macrophages stuck in the affected part of the artery wall in this process. Over time this results in plaque being built up, consisting of cholesterol and macrophage white blood cells.

The plaque clogs up the artery, disrupting the flow of blood. This potentially causes blood clots that can result in life-threatening conditions such as *heart attack* and other cardiovascular diseases.

Some risk factors are follows: age, sex, familial predisposition, hyperlipidemia, hypertension, diabetes mellitus, smoking, obesity, insufficient physical activity, etc. Whatever the main reason or the risk factor is, once atherosclerosis is formed, several life-threatening cardiovascular disorders can be seen. So, it has to be revealed.
