Cardio vascular disorders

Cardio vascular disorders, lymphatic system, open heart surgery 

  Cardiovascular Disorders

Many disorders are associated with the circulatory system. Some of the significant are the following. 

Thrombosis and Embolism

Thrombus is a Greek word which means blood clot. It is formed by the aggregation of platelets inside the vessels. The disorder in which a person generates a thrombus in a vessel is called thrombosis. A thrombus in a blood vessel is very painful. A thrombus in a large blood vessel decreases blood flow through that vessel but in a small blood vessel it may completely stop the blood flow resulting in the death of tissue supplied by that vessel. Risk of thrombosis increases in certain conditions like atrial fibrillation, heart valve replacement, a recent heart attack, extended periods of inactivity. Sometimes genetic factors make a person more prone to thrombosis. Generally bed ridden patients and people like barbers who keep standing for hours as part of their daily routine suffer from this disorder. A thrombus which dislodges and becomes free-floating is termed as an embolus. The term embolus was coined byRudolph Carl Virchow in 1848. An embolus migrates from one part of the body,through blood circulation, and causes a blockage of a blood vessel in another part of the body.In thromboembolism, the thrombus from a blood vessel is completely or partially detached from the site of thrombosis. The blood flow will then carry the embolus (via blood vessels) to various parts of the body where it can block the lumen and causes vessel obstruction or occlusion. One of the most commonly recognized problems caused by the embolus is called coronary thrombosis. In this case, the thrombus blocks a coronary artery causing myocardial infarction commonly known as a heart attack. Even worse situation appears when the thrombus blocks an artery to the brain. This is commonly called as stroke. A stroke may result in sudden death or paralysis of the body.

Atherosclerosis and Arterioscle

Atherosclerosis: (Gr. Arthere = porridge, skeleoris = hardening) is the condition in

which the wall of artery thickens as the result of deposition of fatty materials such as cholesterol. It develops from low-density

lipoprotein molecules (LDL) becoming oxidized by free radicals. When oxidized LDL comes in contact with the wall of an artery, a series of reactions occur to repair

the damage to the artery wall caused by oxidized LDL. The body's immune sends specialized white blood cells called

macrophages and T-lymphocytes to

absorb the oxidized-LDL, forming

specialized foam cells. Unfortunately, these white blood cells are not able to process the oxidized- LDL. They grow and then rupture, depositing a greater amount of oxidized cholesterol into the artery wall. This triggers more white blood cells and the cycle continues. As a result , the artery becomes inflamed. The cholesterol plaque causes the muscle cells to enlarge and form a hard cover over the affected area. This hard cover causes the artery lumen to become narrow. Narrowing of artery reduces the blood flow and increases blood pressure. Atherosclerosis typically begins in early adolescence, and is usually

found in most major arteries, yet is asymptomatic and not detected by most diagnostic methods until it grows to a serious threat to health. There are various anatomic, Factors add to each other multiplicatively, with two factors increasing the risk of atherosclerosis fourfold. Studies show that Hyperlipidemia (High level of fats in blood), hypertension and cigarette smoking together increases the risk seven

times.

Treatment of Atherosclerosis

physiological and behavioral factors which increase the risk for atherosclerosis.

Instead of medication the first method of treatment advised by the doctors, throughout the world, is to stop smoking, change feeding habits and choice of foods

and practicing daily exercise or at least daily walk. If these methods do not work,

medicines are usually the next step in treating cardiovascular diseases. If

atherosclerosis leads to symptoms like angina pectoris then it becomes necessary to

start medication. Physical treatments which are helpful in the short term include angioplasty procedures that may include stents to physically expand narrowed arteries and major invasive surgery, such as bypass surgery to create additional blood supply connections that go around the more severely narrowed areas. Arteriolosclerosis is any hardening, stiffening or loss of elasticity of arterioles. It is often due to hypertension. The most common sites for arteriosclerosis are arteries in the brain, kidneys, heart, abdominal aorta or legs. Symptoms of arteriosclerosis vary according to the arteries which are affected. Leg pain when exercising might indicate peripheral arterial disease. Sudden weakness or dizziness could be caused by an obstruction in the carotid artery in the neck, which produces stroke-like symptoms. Chest pain or symptoms of a heart attack might indicate

obstruction of the coronary arteries.

Risk factors for arteriosclerosis are more or less similar as that of atherosclerosis. They include smoking, obesity, high blood pressure , high serum cholesterol, stress, and diabetes. A family history of early heart disease is also a risk factor for developing arteriosclerosis.

 Congenital Heart Problem

A congenital heart defect is a defect in the structure of the heart and large blood vessels of a newborn baby. Most of these heart defects either obstruct blood flow in the heart or vessels near it or cause blood to flow through the heart in an abnormal pattern. Defect may also occur affecting the heart rhythm.. Heart defects are among the most common birth defects and are the leading cause of birth defect-related

deaths. Congenital heart disease can be categorized in to different types. In some

babies right ventricle or the left ventricle fails to develop. As a result only one side of

the heart pumps the blood the body and lungs. This defect is called Hypoplasia of the

heart which is rare but is the most serious form of congenital heart defect. Other type of defect may be called as Obstruction defects. Obstruction defects occur when heart valves, arteries, or veins are abnormally narrow or blocked.

Common obstruction defects include blockage of pulmonary valve, aortic valve and bicuspid aortic valve.

Any narrowing or blockage can cause heart enlargement or hypertension

The most common among the congenital heart defects are the defects in the

septa of the heart. The septum is a wall of tissue which separates the left side of the

heart from the right side of the heart. The defect may be in the septum between the atria or the septum between the ventricles. Due to this defect the blood flows from the left side of the heart to the right side. This mixing of oxygenated and deoxygenated blood reduces the overall efficiency of the heart. Septal defects may or may not cause

cyanosis depending on the severity of the defect. Some times the defect is so minor that it requires no treatment and is corrected by itself with the passage of time and increasing age. Major defects require medication and surgery.

 Blue Baby or Cyanosis

One of the effect of congenital heart defect is the birth of blue babies, a physiological condition called cyanosis. The reason for the appearance of blue colour is the formation of carboxyhaemoglobin instead of oxyhaemoglobin in the blood because of limited availability of oxygen. During the embryonic life, heart of the foetus start beating after four month of gestation. In the heart of the foetus , an opening, "foramen ovale" connects the right atrium with left atrium. The blood passes from right atrium to the left without passing through lungs. The reason for this bypass is that the supply of oxygen to the foetus is from the blood of the mother through placenta (and not by lungs). After the birth the foramen ovale closes spontaneously but in some babies it

does not close completely. When the baby exerts force during crying and movement

the deoxygenated blood from the right atrium enters the left atrium through the

partially opened foramen. When the haemoglobin of this venous, deoxygenated blood turns to carboxyhaemoglobin, it imparts blue discoloration to the skin , lips, ears and other organs of the baby, resulting in cyanosis or blue baby.

 Hypertension

Hypertension is a chronic medical condition in which a person suffers pressure the normal BP of a healthy normal adult is 120/ 70 mm Hg and with persistently from high blood pressure. As you studied under the section of bloors increasing age the normal BP also increases. For a normal adult a mercury reading of 130/90 is considered hypertensive. For a women of above forty five years of age BP of 160/95 is considered hypertensive whereas for a man this limit is 140/95.

.Hypertension can be:

**Essential or primary hypertension

** Secondary hypertension

Essential or primary hypertension means that no medical cause is found to

explain the raised blood pressure. It is the most common type of hypertension. About 90-95% of hypertension is essential

hypertension. Secondary hypertension indicates that the high blood pressure is a

result of (i.e., secondary to) another condition, such as kidney disease, Cushing's

syndrome, ( a disorder in which both adrenal glands can overproduce the hormone cortisol) or tumours. Certain medicines like Ibuprofen and steroids can also cause secondary hypertension. Sleep disturbance and pregnancy may also become a cause of hypertension in some people. Persistent hypertension is one of the risk factors for strokes, heart attacks, heart failure and arterial aneurysm, and is a leading cause of renal (kidney) failure. Even moderate elevation of arterial blood pressure leads to shortened life expectancy. At severely high pressures, defined as mean arterial pressures 50% or more above average, a person can expect to live no more than a few years unless appropriately treated.Mild to moderate essential hypertension is greatly asymptomatic. Accelerated hypertension is associated with headache, somnolence, confusion, nausea and vomiting. Retinas are also affected causing visual disturbances. 

Prevention and Treatment of Hypertensio 

Weight reduction and regular aerobic exercise (e.g., walking) are recommended as the first steps in treating mild to moderate hypertension. Reducing dietary intake of sugar and table salt is effective in reducing hypertension. An increase in daily calcium intake has the benefit of increasing dietary potassium, which the oretically can counteract the effect of sodium and act on the kidney to decrease blood pressure. A diet rich in fruits and vegetables and low-fat or fat-free dairy foods are also recommended. Discontinuing use of tobacco and alcohol has been shown to lower the blood pressure. Reducing stress and tensions are also effective in controlling hypertension. In emergency and severe cases antihypertensive medicines are also

used. physiological state, rather than a disease. Not Hypotension is the opposite of hypertension. Hypotension is abnormally low blood pressure. It is considered as a

always but most often hypotension is associated with shock. Hypotension can also be life-threatening. The initial symptom of hypotension is dizziness . If the blood

pressure is sufficiently low, fainting and often seizures will occur. Patients with

hypotension also complain chest pain, shortness of breath, irregular heartbeat and

headache. The most common cause of producing hypotension is reduced blood volume in the body. This reduction in the volume of blood can result from hemorrhage (blood loss) insufficient fluid intake (as in starvation), excessive fluid losses from diarrhea or vomiting, or is often induced by excessive use of diuretics. Some medicines can also produce hypotension by different mechanisms.

Angina pectoris, heart attack and Heart Failure

Angina pectoris or simply angina is a severe, radiating chest pain due to the lack of blood supply to the heart muscle, generally due to obstruction or spasm of the coronary arteries. Main cause of angina, is atherosclerosis of the cardiac arteries, pain

of angina starts from left side of the chest and radiates to left shoulder, neck and

sometimes cerebral region. Angina is the first alarm of the body to show that something is going wrong with the heart. Those who realize and start precautionary measures and bring a change in their lifestyle and diet, they lead a successful and active life. Those who do not care and continue with their life style generally come across a heart attack. It is a common

experience that people survive in first two attacks but mostly third attack is fatal and

results in heart failure.

Treatment of Cardiovascular disorders:

In the above description you studied many ways to prevent and minimize different cardiovascular diseases. These ways help the patients to certain extent but sometimes doctors advise major or minor surgery or some other modern ways to provide relief to the patient. Among these methods some are

*Angiography

*Angioplasty

*Coronary bypass

*Open heart surgery

Angiography is a test that

uses an injection of a liquid dye to make the arteries easily visible on X-rays. An angiogram 15 commonly used to check the

condition of blood vessels. There are

alternatives nowadays to angiography, such as CT scan, MRI scans, nuclear scans, and

ultrasound scans, which often produce information as accurate and useful as angiograms. One method of treatment of

a blocked artery is angioplasty. The

term angioplasty is a the combination of two Greek words: aggeios meaning "vessel" and

plastós meaning "formed" or "moulded". It is the technique of mechanically widening a narrowed or obstructed blood vessel:

typically as a result of atherosclerosis. In this treatment a balloon-tip catheter is passed in the artery. At the site where the lumen

is narrowed due to blockage, the balloon is inflated to a fixed size using water pressures some 75 to 500 times more than normal blood pressure (6 to 20 atmospheres).

This high pressure removes the blockage and opens the artery. Sometimes, to ensure that the lumen remains open, a metallic ring called stent is placed there at the site. This stent remains there as part of the artery and ensures that the artery remain open.

The angioplasty is not restricted to the coronary arteries. Now other arteries which

get narrowed by atherosclerosis are cleared and opened by this procedure generally called peripheral angioplasty. This type

of angioplasty includes renal artery angioplasty, Carotid angioplasty, Cerebral arteries angioplasty etc Another treatment is called Coronary artery bypass surgery

(also called coronary by pass or simply bypass). In this treatment a vessel is taken from some other part of the body and is grafted from aorta to the coronary artery system. This vessel starts supplying

blood to the heart muscles by passing the original blocked artery.This surgery is

usually performed with the heart stopped, necessitating the usage of cardiopulmonary

bypass; techniques are available to perform bypass on a beating heart, so-called "off-

pump" surgery. A successful graft typically

lasts around 10-15 years which means this process sufficiently improves the

chances of survival of a patient suffering from atherosclerosis.

Open Heart Surgery

Any surgery where surgery is performed on the heart muscle, valves,arteries, or other heart structures is termed as open

heart surgery. The term "open" refers to the opening of chest and not the heart itself. The

heart may or may not be opened, depending on the type of surgery. As for sometime

heart is non-functional a heart-lung machine (also called cardiopulmonary bypass) is

usually used during conventional open heart

surgery. It helps provide oxygen-rich blood to the brain and other vital organs. The

definition of open heart surgery has become confusing with new procedures being

performed on the heart through smaller incisions. There are some new surgical procedures being performed that are done

with the heart still beating and is generally termed as beating heart surgery.

Lymphatic System

The lymphatic system is a network of vessels found in vertebrates that carry a milky

fluid called lymph. It also includes the lymphoid tissue through which the lymph

travels. This system transports and returns materials from the tissues of the body to blood. In 1652 the lymphatic ducts in the liver were first described by a Swedish Olaus Rudbeck (1630-1702) and the very next year it was Thomas Bartholin who described these vessels in the whole body and gave them the name of lymphatic vessels.Lymph vessels, at certain points, have masses of connective tissues called lymph nodes. These node (more than 100 in human body) are present in the armpits, groin and neck region. These are the sites of lymphocyte production and storage. They act as barriers to infection by filtering out and destroying toxins and germs. The largest body oflymphoid tissue in the human body is the spleen.

a. Position of lymph nodes:

Lymph nodes generally occur in groups along the larger lymphatic vessels.
They are distributed throughout the body, but they lack the tissues of the central
nervous system. All lymph nodes have the primary function of the production of
lymphocytes, which help defend the body against microorganisms and against
harmful foreign particles and debris from lymph before it is returned to the blood
stream. The nodes are mostly located in following six areas:

(1) The cervical region: 

Nodes in this area are grouped along the lower border of the jaw, in front of and behind the ears, and deep in the neck along the larger blood vessels. They drain the skin of the scalp, face, tissues of the nasal cavity, and the pharynx, lymph from vessels that drain the arm, the walls of the thorax, the breast, and the upper walls of the abdomen.

(3) Inguinal region: 

The nodes in this area receive lymph from the legs, the outer portion of the genitalia and the lower abdominal wall.

(4) The pelvic cavity:

 The nodes here appear mostly along the paths of the blood vessels within the pelvic cavity and receive lymph from the lymphatic vessels in thearea.

(5) Abdominal cavity: 

Within this area, nodes occur in chains along the main branches of the arteries of the intestine and the abdominal aorta

(6) Thoracic cavity: 

These nodes occur between the lungs and along the windpipe and bronchi, and receive lymph from this area and from the internal wall of the thorax.Large lymphatic vessels generally called lymphatic trunks drain lymph from the larger arcas of the body, and they are named for the areas that they serve. The"intestinal trunk" drains organs of the abdominal cavity; the "lumbar trunk" drains lymph from the legs, lower abdominal wall, and the pelvic organs; the "intercostal"and "bronchomediastinal trunks" receive lymph from portions of the thorax, the" subclavian trunk" drains the arm; and the "jugular trunk" drains parts of the neck and head. These trunks then join one of two collecting ducts: 

(a) the thoracic duct or 

(b) theright lymphatic duct.

 These collecting ducts finally drain the lymph into the subclavian veins to become part of the plasma, just before the blood returns to the right atrium of the heart.

The lymphatic system and the cardiovascular system are closely related systems. The lymphatic vessels are present wherever there are blood vessels present in the body. They are joined by a capillary system. When the blood passes through arteries (with pressure), veins and capillaries the water along with certain salts, some plasma proteins etc ooze out in tissuc spaces. This fluid is called interstitial fluid. It is simply blood plasma minus most of the proteins. It has the same composition and is formed in the same way as the filtrate in kidneys.

Interstitial fluid bathes the cells in the tissue space and substances in it can enter the cells by diffusion or active transport. Substances, like carbon dioxide, can diffuse out of cells and into the interstitial fluid. From here this fluid is collected in the fine, very permeable, blind ended capillaries of lymphatic system in the form of lymph which join to make larger vessels. The lymphatic vessels transport this excess fluid to the end vessels without the assistance of any "pumping" action. The lymph contains other materials like its vessels (called lacteals) present in villi in the small intestine absorb products of fat digestioni.c. fatty acids. Along with it lymph. This system is very important for the distribution of fluids and nutrients in the some type of white blood cells called lymphocytes are also transported through body, because it drains excess fluids and protein so that tissues do not swell up.

Our body also eliminates the products of cellular breakdown and bacterial invasion

through this system The is important to the body's defense mechanisms. It filters out

organisms like bacteria, viruses and fungi that cause disease, produces certain white

blood cells called lymphocytes. Some of these lymphocytes make antibodies, which

special proteins that fight off germs and stop infections from spreading by trapping

disease-causing germs and destroying them.

It is through the actions of this system including the spleen, the thymus, lymph

nodes and lymph ducts that our body is able to fight infection and to protect against

invasion from foreign invaders. Lymph plays an important role in the immune system. 

Spleen as lymphatic organ

The spleen, which is located in the upper left part of the abdomen under the ribcage, works as the most important and most efficient part of the lymphatic system

to protect the body, clearing worn out red blood cells and other foreign bodies from the

bloodstream to help fight off infection. The spleen contains lymphocytes and another

kind of white blood cell called macrophages, which engulf and destroy bacteria, dead

tissue, and foreign matter and remove them from the blood passing through the spleen.

Role of macrophages in the prevention and control of cancer is also very important,

Lymphatic system and cancer. 

The study of lymphatic drainage of various organs is important in diagnosis, prognosis, and treatment of cancer. The lymphatic system, because of its physical proximity to many tissues of the body, is responsible for carrying cancerous cells between the various parts of the body in a process called metastasis. The intervening lymph nodes can trap the cancer cells. If they are not successful in destroying the cancer cells the nodes may become sites of secondary tumors.

Diseases of lymphatic system

Diseases, infection and other problems of the lymphatic system can cause swelling in lymph nodes and other symptoms as well. Problems with the system can spreads throughout the lymphatic system, including the spleen. Pressure on Hodgkin's disease is an enlargement of the lymph nodes in the neck, which gradually spread through out the lymphatic system, including the spleen pressure on adjoining organs and nerve endings can result in a dysfunction of vital organs or in paralysis.