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The cardiovascular system
The cardiovascular system (CVS) is a complex arrangement of hydraulic systems. This system comprises mainly 3 parts: the heart, the blood vessels and the blood. The heart is considered as the main pumping machine of blood and the blood vessels act as the delivery routes. The cardinal task of the CVS is to transport oxygen, carbon dioxide, numerous chemical compounds, and the blood cells via these media.

Anatomy and physiology
In the human body, the heart is situated between the lungs, slightly towards the left of the center. It is a muscular organ having size approximately that of the fist. The heart can be divided into two parts, the left and right parts. Furthermore, each part has two chambers, atrium and ventricle. A muscle called Septum separates the right atrium and right ventricle from the left atrium and left ventricle.

The heart consist of four valves and the short description is given below:

The Tricuspid valve / Right atrioventricular valve
It lies between the right atrium and the ventricle. It consists of three flaps. It stops the return flow of blood from the right ventricle to the right atrium.

Bicuspid valve /Mitral valve/ Left atrioventricular valve
It lies between left atrium and left ventricle. The valve has two flaps It stops the return flow of blood from the left ventricle to the left atrium.

Pulmonary valve
It can be seen at the right ventricle. It consists of three half-moon-shaped cusps. This does not allow blood to come back to the right ventricle.

Aortic valve
It lies between the left ventricle and aorta. Its construction is similar to the pulmonary valve. This valve prevents the backward blood flow to the left ventricle from the aorta

The wall of the heart consists of three layers of tissue:

Epicardium : Connective tissue to provide protection.

Myocardium : Also known as the cardiac muscles, comprises core tissues of the walls of the heart.

Endocardium : Provides protection to valves and chambers inside the heart.

Pericardium: Covers the entire heart with a layer of muscle and cushions with a fluid called pericardial fluid.

The blood is transferred to the various body-parts through blood vessels. There are three types of blood vessels:


 * Arteries: It is thick-walled and carries the oxygenated blood away from the heart.
 * Veins: These are thin-walled and carry deoxygenated blood towards the heart.
 * Capillaries: These are the smallest and the last level of blood vessels.

Note: Only during when the blood is carried to the lungs and vice versa, the Pulmonary Veins carry oxygenated blood and Pulmonary arteries carry the deoxygenated blood.

Electrophysiology
The heart pumps blood that travels throughout the body. In order to achieve this successfully, the heart muscles need to have a perfect coordination, pumping blood at the correct time, direction and pressure.

The cardiac cycle
The top right atrium (Sinoatrial, SA node) generates electrical impulse

↓

Both the right and left atria contracts by receiving this impulse, thus pushing the blood down into the ventricles via Atrioventricular (AV) node

↓

The signal is slowed down at AV node to avoid the contraction of atria and ventricle at the same time

↓

From there on the impulse is carried on to the ventricles causing them to contract

These electrical activities of the heart can be detected by an instrument called electrocardiograph and recorded on a graph paper with wave-like patterns called the electrocardiogram (ECG). Any atypical pattern if detected can be due to fluctuations in the electricity spread, resulting in different forms of arrhythmia (abnormal heartbeat).

Aorta and main arteries
The aorta is the prime and largest artery in fact the largest blood vessel in the human body. It originates from the left ventricle of the heart and runs down to the abdomen and there, it bifurcates into two smaller arteries, the common iliac arteries. The aorta supplies oxygenated blood to the circulatory system.

The other arteries related to the heart are coronary arteries namely (1) Left main coronary artery (LMCA) and (2) Right coronary artery (RCA).


 * Left main coronary artery (LMCA): The left prime coronary artery which supplies blood to the left heart muscle which is the left ventricle and left atrium. The LCMA is further divided into branches:
 * The left anterior descending artery: It originates from the left coronary artery and supplies blood to the front of the left side of the heart.
 * The circumflex artery: It originates from the left coronary artery and encircles the heart muscle. This artery supplies blood to the outer side and back of the heart.
 * Right coronary artery (RCA): The task of the right coronary artery is to supply blood to the right ventricle, the right atrium and the sinoatrial (SA) and atrioventricular (AV) nodes, which controls the heart rhythm. Again, the RCA bifurcates into smaller branches which are the right posterior descending artery and the acute marginal artery. Unlike the left anterior descending artery, the right coronary artery supplies blood to the middle or septum of the heart

Venous system and blood supply to and from the lung
The deoxygenated blood reaches the heart via superior vena cava and inferior vena cava and pours the blood to the right atrium, and then the blood is pumped into the right ventricle. The ventricle then pumps it into the pulmonary arteries. The pulmonary arteries carry the deoxygenated blood into the lungs for oxygenation. The blood is oxygenated inside the lungs with the help of Dalton's principle of gas transfer. The blood capillaries are set in between alveoli. During inhalation, the lungs sucks in O2 and carry it to alveoli and the O2 is then transferred to the blood in capillaries and hence the blood is oxygenated. Then the oxygenated blood is carried in pulmonary veins and carried to the left atrium of the heart. And then it is transferred to the left ventricle and then pumped to the aorta. The aorta supplies blood to the rest of the body.

Access to the arterial systems

 * Intra-arterial applications are performed by coronary catheterization process, minimally invasive medical technique. In this technique the way to the heart is achieved by guiding a thin tube, called a catheter, in the broad arteries from groin, neck or arm. This process is majorly used in diagnostic, dilation and stenting procedures for any cardiovascular related disease.

Endothelium

 * It is made of squamous endothelial cells which lines the interior of the blood and lymphatic vessels. It acts as an interface between blood/lymph and lumen. It controls the flow of fluid into the tissue. The endothelium present in the heart is called endocardium which lines the inner layer of chambers. During the myocardial infarction, the endothelium of the coronary artery gets damaged and hence the deposit of plaque happens and results in the former issue.

Size of catheter

 * In case of dilation and stenting procedure the diameter of the catheter remains 5-6 French (~2.0mm) in diameter. Although the length of the catheter tube varies from 138-152 cm.

Stents

 * The treatment, dilation, is used to widening the blood vessels (by removing the plaque from the artery) to regain the normal blood flow. Several types of technology are used in the dilation process which are "balloon dilation", "laser angioplasty", "laser-guided balloon" and "atherectomy". Although, the dilation process has some drawbacks. The process of angioplasty, widening the blood vessels, damages the wall of arteries. As a result the new tissues grow when the injured wall of artery heals. Eventually, again it narrows the vessel and reduces the rate of blood flow. The problem of re-stenosis is again alleviated by implementing stent. The stent is a viable option during a cardiac arrest in a patient and it is an extension of coronary angioplasty. After the balloon catheter unblocks the thrombus in the coronary artery, the stent is fixed into it in order to keep it dilated. It is usually a metallic cylindrical mesh. But with the increasing technology, the stents come in a polymers and bioabsorbable type. The bioabsorbable polymeric stents/scaffolds will degrade completely inside the coronary artery within a year or two. The stents also come with a drug-eluting type that elutes drugs like Sirolimus/rapamycin, paclitaxel, everolimus etc., which prevents the foreign body rejection by suppressing the antibodies.

Prevention of clotting
The clotting can be formed naturally as well as with the introduction of metallic stents. The naturally caused thrombus can be removed either by coronary angioplasty for an emergency as well as normal cases, and also can perform bypass surgery too. In order to prevent the development of further thrombus, the stent is used, yet sometimes the stent acts as a catalyst for the development of thrombosis. So in that case, bioabsorbable polymer stents can be used.

Outline of the manuscript

 * 1) Abstract
 * 2) Introduction
 * 3) The Anatomy (gross anatomy, histology) and Physiology
 * 4) The main aspects of the disease
 * 5) Impacted organ
 * 6) Pathological changes
 * 7) Symptoms
 * 8) Medical Treatment Options
 * 9) Diagnosis
 * 10) Dilation
 * 11) Stent implantation
 * 12) Technical or Physiological challenges
 * 13) Own ideas for technical development
 * 14) Conclusion
 * 15) References

Team Information
Team name: J

Team Members:


 * Dibyasree Biswas
 * Joy Rakshit
 * Sidharth Thambiraj
 * Sumeet Yogeshwar Dekate