THE CARDIOVASCULAR SYSTEM

COURSE OBJECTIVES:

Upon completion of this course the student will have a better understanding and knowledge base of what the cardiovascular system is, its functions and what can go wrong. The student will understand their role in education, prevention and care of a patient with a changes or a disorders related to this vital body system.

LEARNING OBJECTIVES:

  1. The student will have a verbal knowledge of the basic anatomy & physiology of the Cardiovascular system and be able to use this in the care of the cardio patients..
  2. The student will have a basic concept of congenital disorders in the cardiovascular system and be able to identify their role in these disorders.
  3. The student will have verbal knowledge & be able to ID the signs and symptoms of cardiovascular diseases and verbalize the nursing role for each.
  4. The student will have the verbal knowledge of therapeutic procedures and developments in cardiovascular care and surgery and the nurses role.
  5. The student will have the verbal knowledge of preventive measures related to the cardiovascular system and be able to educate their patients.

INTRODUCTION:

The Mosbyís Medical, Nursing, & Allied Health Dictionary, 1998, describes the cardiovascular system; the network of anatomic structures, including the heart and blood vessels, that pump blood throughout the body. The system includes thousands of miles of vessels to deliver nutrients and other essential materials to fluids surrounding the cells and to remove waste products.

The heart and itís vascular system constitutes a huge part of the bodies functioning. Each of the bodies systems are very important to each other in giving survival to the rest. The importance of a healthy & functioning cardiovascular system are made evident in this lesson. These words are spoken not only to increase your fundamental understanding for your patient but to enhance your skills as a health professional. Just as important are the words and their significance here for your knowledge base, they reflect a healthy and happy life for yourself as an individual. As a person who gives so much of them selves for others, you deserve to have a healthy cardiovascular system as well. When you are happy and healthy holistically your patients and your co-workers all benefit from this blessing.

ANATOMY AND PHYSIOLOGY

The Heart: Look at your fist, this is the approximate size of your heart. Unlike other muscles that you might work to increase their size, enlargement of your heart is not something you want. The normal adult heart weighs about 11 ounces. The heart sits in the thoracic cavity between the lungs, more on the left side of the chest. Most of the heart consist of muscle (myocardium). This muscle is covered by two protective layers, the outer layer is the epicardium and the inner layer is the endocardium.

The heart is divided into two sides, the right and the left. Each side has a atrium on the top and a ventricle on the Bottom. The heart receives blood through the largest vein in the Body, the Vena Cava. This vein brings blood back to the heart that is not oxygenated, it enters from the inferior and superior vena cava into the right atrium.. It has picked up non oxygenated blood from all parts of the body.

The heart has an electrical system that assists with all of its productions. The electrical system consist of the senatorial node SA (the natural pacemaker) this is a bundle of muscle fibers and nerves that sit at the top of the right atrium. At regular intervals an electrical impulse is received from this pace maker causing the muscle of the right atrium to contract in a wavelike motion from top to bottom. The squeezing of the muscle fibers puts pressure on the blood in the right atrium and pushes it through the tricuspid valve into the right ventricle. Just as the ventricle fills with non oxygenated blood another electrical impulse is sent from the AV node ( atrioventricular). This is another bundle of muscle and nerves, located in the wall/ septum between the two ventricles. The AV node is triggered by the SA node passing electrical shock waves down into two pathways ; the bundle of his and the Purkinje fibers, quickly stimulating the rest of the heart.

Once the non oxygenated blood has passed from the right atrium into the right ventricle through the tricuspid valve A mounting pressure forces the trapped blood to find an way out, as the pressure becomes greater then that of the pulmonary artery, the pulmonary valve is pushed open. The pulmonary artery is the only artery in the body that passes non oxygenated blood through it. Passing through the branches of the pulmonary artery, the blood eventually touches down into the bottom of the lungs. It then reaches the alveoli, making its exchange of non oxygenated blood for oxygenated blood. This freshly oxygenated blood, all bright and red as a result of the infusion of oxygen, drains into a pair of pulmonary veins (these are the only veins in the body that carry oxygenated blood). The blood then exits out of the lungs back into the heart, finding its way into the left atrium. The same nerve impulses that stimulated the right side also stimulate the left . The electrical impulse is sent causing a contraction, the force of the contraction forces the blood in the right atrium to look for a way out.

The bright red blood is forced through another valve called the bicuspid (mitral valve). The blood then enters into the largest chamber of the heart, which is the left ventricle.

As the wave of the electrical impulse shocks the heart again the left ventricle contracts, and begins to compress pressure into the chamber. The mital valve (as all the valves in the body) prevents blood from flowing backwards; leaving the only escape for this compressed blood to leave through is the aorta. The aorta is the largest artery in the body, it is the pathway of the cardiovascular system. Oxygenated blood is now on its journey to all of the farthest reaches of the amazing human body.

The vascular system consist of arteries and veins. The arteries are bright red, they leave the heart with oxygenated blood and take it to all of the living cells. The brightly red oxygenated blood that is being delivered from the arteries is nourishing all of the cells with O2 and the nutrients ,these are essential for a cell to survive.

Arteries are thick and have great ability to expand. Arteries have to endure a lot of pressure from the intense flow of the blood. The veins are not as thick as the arteries and they have valves. The valves are used to stop the non oxygenated blood from backing up into the oxygenated blood. The veins pick up the blood after the cells have taken all of the needed 02 and nutrients. The veins then bring it back to the heart through the vena cava to get refilled. It is a huge transportation system, all working in a perfect synchronically.

This whole process sounds complicated and time consuming, but in all reality this whole trip through the heart takes less then one second and the process of the entire bodies blood system to circulate takes less then one minute.

So complex, and so many things can go wrong, I will show you what I mean..

STATISTICS

Heart diseases have been the leading cause of death in the United States for decades. There has been considerable progress in the fight against heart disease yet it continues to kill many. One American dies of heart disease every 30 seconds, and from heart attacks every minute. More women then men die from heart disease, because of the longevity in women. The countryís awareness and the political backing has allowed considerable progress to be made in this area of concern. The death rate from cardiovascular disease today is only 45 % of what it was in 1963, in addition increased life expectancy in the American population is mostly due to the decrease in cardiovascular deaths. Better scientific understanding, social education and therapeutic modalities have been the number one reason for these extraordinary changes. We have begun to become a culture of preventative consciousness.

This all sounds great but do not let us put a band aid over a still gaping wound.. Cardiovascular disease is still a very serious problem in our culture, and most likely in you or someone close to you.

CONGENITAL DISORDERS OF THE HEART:

Most of the time when we are discussing Cardiovascular Disease, we are speaking of people who are older and who have lived some years on this planet allowing things into their bodies that can cause damage to their cardiovascular system.. Diseases. Many small children donít have the option of good or poor vascular habits, they are born with a congenital abnormality.

At the end of the first month of pregnancy a fetal heart begins to develop. At the end of the second month a tiny replica of a adult heart has been made.

This tiny heart has twisted and turned and has completed its amazing production of all the parts of the heart; the atriums, and ventricles, the septum and the SA and AV nodes, all present. The heart is there, but a major portion of its functions remain dependent on the mother, this dependency continues even after the fetal heart begins to beat. The growing fetus has an opening between the pulmonary artery and the aorta, where oxygenated blood and non oxygenated blood sometimes mix. This is not a serious issue while in the womb, the fetus is still dependent on its mother for its breathing and nutrition.

At birth a new circulatory system develops in the infant. At the time the baby begins to breathe on itís own this opening closes. Now blood pumped from the right ventricle can flow into the lungs. The heart of the baby continues to change and close and get stronger during the first year of life. This is all so complexed, yet only 1 in 1,000 babies are born with any congenital heart defects.

Patent Ductus Arteriosus- This was the first human congenital cardiac defects to be surgically repaired. The area between the pulmonary artery and the aorta does not close. This can cause weakness and retards growth and heart failure may occur. Surgical correction is the only effective treatment.

Coarctation of the Aorta- Fairly common, This is a severe narrowing of the aorta that produces an obstruction of flow. Surgical correction is necessary.

Tetralogy of Fallot- This is four separate problems in the heart. The primary defects are narrowed pulmonary valve, an opening in the septal wall between the ventricles. In addition, there is biventricular origin of the aorta and right ventricular hypertrophy. This defect causes several problems. The heart canít pump enough blood, oxygenated and non-oxygenated blood mixes. The child is starved for oxygen. Cyanosis = The blue baby. Surgery is necessary.

DISEASES OF THE CARDIOVASCULAR SYSTEM

Myocardial Infarction,Ē MIĒ (HEART ATTACK)

Tissue damage or death of tissue to the heart muscle, caused by a lack of, or obstruction of oxygen to one or more of the coronary arteries. This can be caused by atherosclerosis (narrowing of the arteries), thrombus, (traveling blood clot) or by a spasm.

Signs and Symptoms: the onset of an MI is characterized by crushing, viselike chest pain that may radiate to the left arm and neck area. Epigastric pain that sometimes stimulates the sensation of acute indigestion or a gallbladder attack. The person usually becomes gray, clammy, short of breath, faint, and very anxious, they may feel they are looking death in the face. Tachycardia (fast heart rate, over 100 per minute), hard to find pulse, low blood pressure. The EKG might show evidence of elevation of ST segment and Q wave. Laboratory studies usually show an increased sedimentation rate, leukocytosis, and elevated serum levels of creatine kinas and its is enzyme MB.

Some of the serious problems associated with an MI are; pulmonary or systemic emboli, pulmonary edema, shock, ventricular tachycardia, ventricular fibrillation and cardiac arrest.

Emergency Interventions; May require CPR, early IV heparin for thromboysis.

Nursing measures; V/S taken frequently, (apical pulse), IV fluids, a low sodium low cholesterol diet, stool softeners and laxatives to prevent straining. Education to patient and family on the nature and treatment of the disease. Diet, exercise, medications are very important. Things to avoid: are caffeine, nicotine, large meals, and emotional stress.

CEREBROVASCULAR ACCIDENT, CVA ( Stroke)

A stroke is a sudden loss of brain function from a disruption of the blood supply to a part of the brain. The cause is usually brought on by one of four things: 1. Thrombosis ( blood clot within the vein) 2. Cerebral embolism 3. Ischemia (decrease of blood flow to an area of the brain) 4. cerebral hemorrhage. The result from the above disorders is an interruption of blood flow into the brain. This can cause temporary or permanent loss of movement, thought, memory, speech, or sensation.

The acute phase of a stroke is the first 48 to 72 hours. Maintaining airway and adequate ventilation are critical in the acute phase.

Signs and Symptoms- A change in the level of consciousness or responsiveness may occur. There may be a resistance to move, or change positions, poor response to stimulation, and poor reality orientation. Absence of, or over reaction to movement to extremities, stiffness or flaccidity to neck, eye opening, unequal and poor reaction time of pupils, change in the color and temperature of face and skin, changes in V/S, change in I & O.

Nursing Measures; Positioning - this is very important to prevent decubitis ulcers and contractures. Standing and gaining balance, ambulating, ADLís,( dressing, bowel and bladder control, eating ) improving thought process, Improving coping strategies.

HYPERTENSION; ďThe silent killer.Ē

This name is given because many times there are unnoticeable symptoms. A person can have hypertension for years without knowing it. If hypertension is left untreated it can be very serious. It can lead to an MI, CVA, enlarged heart, damage to the kidneys and to the retina of the eye. Hypertension is the leading chronic illness in adults in the United States today, effecting over 50 million people.

There are two types of hypertension, secondary, is caused by something; a medical condition; such as kidney disease. Once the primary problem is dealt with the secondary Dx of hypertension many times goes away. Then there is essential hypertension. This is the most common form of this disease. With essential hypertension the blood vessels are excessively contracted, narrowed or contain excess fluid (edema). This can be caused by hardening or narrowing of the vessel from plaque build up, blood clots.. Hypertension can not be cured but if treated with lifestyle changes and medications it can be controlled. Diet and stress reduction are very important.

Uncontrollable risk factors:

Heredity, a person who has close family members with hypertension are more likely to acquire hypertension. Age: blood pressure increases with age, starting after 30. Sex: more common in men then in women. Race: more common in Afro Americans then in Caucasians.

Controllable risk factors:

Obesity: causes the heart to struggle in order to supply excess tissue with blood. Sedentary Lifestyle: couch potatoes are 50 % more likely to develop hypertension. Alcohol consumption: can cause hypertension and results in a resistance to medication given for hypertension. Sodium: a strong link between sodium intake and hypertension (edema). Cigarette smoking constricts blood vessels.. .

These are just a few of the diseases of the Cardiovascular system. These are the ones you will deal with most often.

NURSING ASSESSMENT:

A patient presents to you with many complaints what do you do? You want the patient to describe for you; the onset, duration, location, and characteristics of any pain present, the occurrence of weakness, fatigue, shortness of breath, fever, coughing, wheezing, and palpitations.

Questions are asked about episodes of fainting, indigestion, nausea, edema of the extremities, cyanosis, vision changes, whether the hands and feet ever feel numb or cold. The personís general appearance, V/S, pressure in the neck veins, lung sounds (address any fluids) skin turgor, skin color, neuro signs, reality orientation. Obtain back ground history leading up to the incident.

NURSES ROLE. The nurses role is to obtain an assessment, (within their scope of practice), document any and all findings. Instruct on proper diet, medication (as to scope of Practice).

THERAPEUTIC PROCEDURES:

Coronary Angioplasty: This procedure was developed back in the 1920s, when a physician first inserted a catheter into his own vein. It wasnít until 1977 that a dilation of a coronary artery was done. Now used world wide, this technique enlarges a blood vesselís passageway by applying pressure from the inside out.

A cardiologist or surgeon positions a slender tube (catheter) into a constricted vessel, then by exposing and inflating a balloon that is carried along within the tube the doctor is able to compress and split the plaque obstructing the vessel. At the same time stretching the vessel wall, widening the passage way. The circulation can then perform its job more effectively now.

Pacemaker Implantation:

As you learned in the previous portion of this course, the heart has a pacemaker, the SA node. Many times from a disease process the pacemaker does not do its job. This causes the heart to not beat as it should. Many times a persons heart will decrease its beats (bradycardia, heart rate below 60 )to a point where the body is not getting enough blood to the feed the needed tissue or organs. These patients may feel symptoms of debilitating fatigue, exercise intolerance, and episodes of unconsciousness due to insufficient blood flow to the brain. Pacemakers meet these needs. These devices have come a long way. They do not just keep a steady beat but they can respond to changes in physiologic requirements, follow programming and communicate. Some know when the patient is at rest or when they are active. A pacemaker may be temporary or permanent.

Open heart surgery is nothing new and is performed everyday throughout the world. People have one way to five way bypasses. Meaning that their coronary arteries are blocked and there is no way the needed oxygen to get to the heart muscle, The Heart Attack!

The needed vessels are removed from the patients own legs, this prevents rejection of the body, it also leaves any increased compromise to the patient. They now have a large incision down the center of their chest, which stands for a major surgery and a new chance at life, but they also have incisions and pain to their leg or legs. The patient is not kept in the hospital for very many days after open heart surgery, and their recovery time is less then expected, if all goes well.

These procedures are all wonderful and have come a long way over the years, millions of people are saved and given new opportunities at life every year. The sad part is many do nothing to change the problem that caused the cardiovascular issue in the first place.

As a nurse we can help the patient to heal their wounds and get the right medications but without major life changes the nurses role is very limited.

As a special person and a angel of mercy, ( the health professional ) you owe it to yourself and to your patients to keep abreast of current information, maintain proper nutrition, exercise (not just walking around your job, or to and from the car), Watch your habits, ( you all know which ones, cigarettes, alcohol, drugs), Stress is a killer. Bitterness is also a insidious pathway to disease, so donít fall into these traps.. Yesterday is gone, Tomorrow may never come, Today it is a gift, the PRESENT.

Let us be the best we can be, and in turn it will give all the people that pass through our lives an example of how they to can aspire to whole health as well. Thank You and God Bless You.

Have fun each day, share your laughter, and give away a lot Of your beautiful smiles :)

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