...Cardiac Muscle Tissue and It’s Function There are different types of muscle tissue in the body. I will be focusing on cardiac muscle tissue and its functions. Cardiac muscle is located in the heart wall and its major function is to pump blood throughout the body. If you were to put cardiac muscle and skeletal side by side you would see that cardiac muscle fibers are shorter in length and less circular. They are described as: “Branched striated fibers with usually only one centrally located nucleus (occasionally two). (Jenkins&Tortora,(2012) p. 132) Cardiac muscle fibers connect to each other by intercalated discs. Intercalated disc are “Transverse thickenings of plasma membrane called intercalated disc which contain desmosomes and gap junctions.” (Jenkins&Tortora,(2012) p. 132) Desmosomes are the glue of the cardiac muscle they hold it together even through constant athletic movement. For example exercise, if there were no desmosomes in the cardiac muscle it would simple fall apart then minute you jumped on a treadmill or began and exercise routine. “Desmsomes strengthen tissues and hold fibers together during vigorous contractions.” (Jenkins&Tortora,(2012) p. 132) Gap junctions make it possible for action potentials to move through one muscle fiber to the next. “Gap junctions provide route for quick conduction of electrical signals throughout heart.” (Jenkins&Tortora,(2012) p. 132) We don’t have to tell our cardiac muscle to contract it does this all...
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...Cardiac Conduction To complete this worksheet, select: Module: Distribution Activity: Animations Title: Cardiac Conduction 1. What is the function of the Conduction System? All cells must contract in a specific sequence. This sequence is determined by the pathway known as the conduction system. 2. Cardiac cells are connective and autorhythmic. What does this mean? Connective cells, action potentials, (excitatory signals) can propagate from one cell to another via gap junctions. Autorhythmic cells can excite themselves spontaneously without stimulation of the nervous system and contract at a regular rhythm. 3. Cells from different parts of the heart’s conduction system have different natural rhythms. What are the average beats per minute at each of the following parts of the heart? a. Sinoatrial Node (SA) 100 bpm b. Atrioventricular Node (AV) 40-50 bpm c. Ventricles 20-40 bpm 4. What is the function of the SA Node? Describe how this happens. The healthy heart’s pacemaker, SA node triggers contraction because it depolarizes at a faster rate than other parts of the conduction system. 5. The AV node starts a series of events that leads to ventricular contraction. Describe this series of events. The AV node is the only connection between the atria and ventricles, once the signal passes the AV node, it propagates through the ventricular...
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...The conductive properties of cardiac tissue are an important part of an arrhythmogenic substrate. In a healthy heart rapid transmission of excitation and the refractory period, in which tissues remain unexcitable immediately following activation, work in concert to prevent reentry and arrhythmogenesis. Various diseases alter the conductive properties of myocardium, e.g. ischemia, creating favorable conditions for ectopy and reentry (Janse et al. 1980, Schalij et al. 1992, Wilders et al. 2000). Specifically, cardiomyopathies that cause a decrease in conduction velocity (CV), the rate of activation propagation through the myocardium, favor arrhythmogenesis by decreasing the critical wavelength necessary to foster reentry (Mines 1914). However,...
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...The Factors that effect cardiac output The Cardiovascular system is responsible for the transport of blood, oxygen and nutrients, to the tissues in the body. There are two components that are important to the system the heart, which pumps the blood, and arteries and veins that transport the blood to and from the tissues. The function of the system is crucial during exercise. Studies involving cardiovascular system focuses on the responses and adaptions of the cardiovascular system to exercise, such as the effects of the structure and function of the blood vessels and the relationship between exercise and neurological control of the heart i.e. cardiac output. Cardiac output is the amount of blood pumped out of the heart in a minute. Cardiac output is determined by the equation Q = HR x SV, the amount of blood expelled with each beat (stroke volume) in combination with the number of beats per minute (heart rate), the amount of blood return, and the resistance to blood flow through vessels. During exercise the heart rate usually increases causing an increase of cardiac output and bringing more blood to the muscles. However, heart rate alone doesn’t improve cardiac output, but along with muscle demand of oxygen. The demand for more oxygen causes vasodilation, allowing an increase in blood flow and the return of blood back to the heart. Some factors that facilitate improvement in cardiac output for performance are intensity, duration, and aerobic/anaerobic exercises. ...
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...Sudden Cardiac Arrest The problem of heart attack is too often misunderstood with cardiac arrest by a lot of people. Thought the reality is quite different as these two are very different heart-related problems which require different treatment and aftercare. What is a Heart Attack? Heart like all other muscles in the human body requires an uninterrupted oxygen-rich blood supply to function properly. Heart receives this through coronary arteries. When a coronary artery is blocked it stops the oxygen-rich blood from flowing into one part of the heart. The section with interrupted blood flow slowly begins to die, and the damage keeps increasing with the delay in the process of treatment. The symptoms of heart attack can either occur immediately or might take few hours or weeks...
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...Senior Project 88% of Sudden Cardiac Arrest (SCA) cases occur in the victim's home. Roughly 70% of Americans do not know how to administer Cardiopulmonary Resuscitation (CPR), or have not kept up on the required training. 326,000 people in the United States are hospitalized due to SCA. In order to gain a better understanding of Cardiopulmonary Resuscitation one must know where it originated. The ten year period from 1950-1960 was a decade of improvement for resuscitation measures. Peter Safar, James Elam, and The United States Military were all contributors to the development of all forms of resuscitative revival. Elam and Safar were the first people to discover mouth-to-mouth resuscitation. Soon after CPR was developed. Over the last few...
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...Cardiac Death VS Brain Death Brain death indicates that a person is dead, not because unconsciousness is attributable to the brain, but because the brain function is a necessary prerequisite to maintaining the vital function of the organism. The perception of the onset of death in the case of brain death is different to that in the case of cardiac death, when the body changes almost instantly to the state associated with dead people: breathing stops, the body cools off and the color of the skin pales. If, on the other hand, the deceased person has been declared brain-dead, the body will still feel warm, and the skin will be its normal colour. Although the relatives have reliable medical information that death has set in, they have to overcome the mental barrier that is deep-rooted in human nature: that as long as the heart is beating and there is breathing, there is life, and thus hope. Furthermore, although specific bodily states can be cited that involve the onset of death in specialist medical terms, people have different views of what it means to be dead, and how body and soul belong together. Being dead is not just a concept in medical science, but also an existential concept, and recognition of the brain death criterion is largely dependent on emotional and experiential aspects. Sudden cardiac death (SCD) is a sudden, unexpected death caused by loss of heart function (sudden cardiac arrest). Sudden cardiac death is the largest cause of natural death in the United States...
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...Cardiac Tamponade After Removal of Temporary Pacer Wires Cardiac Tamponade After Removal of Temporary Pacer Wires The topic of my research paper is Cardiac Tamponade After Removal of Temporary Pacer Wires. Mahon, Bena, Morrison, and Albert (2012) stated “The study was approved by the hospital’s institutional review board” (p. 434). There were no informed consents obtained, information was collected from the Society of Thoracic Surgeons Adult Cardiac Surgery Database and from health care provider’s documentation of reoperation due to bleeding (p. 434). Nieswiadomy (2012) stated “Although there is no signed consent The American Nurses Association Research and Study Commission published a set of guidelines for nursing research such as subjects must be protected from harm, their privacy should be ensured and their dignity preserved” (p. 22). In the research no one could identify the subjects and the information was divided into groups and given codes (p. 434). Confidentiality was maintained, patient’s names were not mentioned, and codes were used instead of names. According to Nieswiadomy (2012) “To assure anonymity or confidentiality, subjects and the site where the study was conducted should be described in general terms in the description of the sample and the setting. If either the subjects or the study location can be identified by this general description, confidentiality has been violated” (p. 26). The subjects were not exposed to any health risks. This research...
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...Running head: CARDIOVASCULAR PAPER 1 Cardiovascular Paper: R.G.’s Risk Factors for Cardiovascular Disease CARDIOVASCULAR PAPER 2 Cardiovascular Paper: R.G’s Risk Factors for Cardiovascular Disease In almost every year since 1900, cardiovascular disease has been the number one cause of death in the United States. Nearly 2300 Americans die of CVD each day, and average of one death every 38 seconds. This disease kills more people than the next four causes of death combined, including cancer, chronic lower respiratory diseases, accidents and diabetes. Of particular concern is that CVD is the leading cause of death for women (Ignatavicius and Workman, 2013). Risk Factors Gender According to, Huether and McCance (2012) more women in the United States die from coronary artery disease and stroke than from all cancers combined. Women have a higher rate of CAD related mortality than men, in part because of under diagnosis and treatment. Menopause is associated with increased exposure to risk factors and poor endothelial healing. Endogenous estrogen is said to be protective of vascular function and when this is reduced after menopause hits the risk of CAD increases. Postmenopausal women are two to three times more likely than premenopausal woman to have CAD. Diabetes Diabetes mellitus is an extremely important risk factor for CAD. Insulin resistance and diabetes have multiple effects on the cardiovascular system including endothelial damage, thickening...
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...Cardiac Catheterization Paper 11/17/2011 1) Describe the procedure of cardiac catheterization: Cardiac Catheterization (Cath) is a specialized study of the heart during which a catheter, or thin hollow flexible tube, is inserted into the artery of the groin or arm. Under x-ray visualization, the tip of the catheter is guided to the heart. Pressures are measured and an x-ray Angiogram (Angio) movie of the heart and blood vessels are obtained while injecting an iodinated colorless "dye" or contrast material through the catheter. Coronary angios are obtained by injecting the contrast material into the opening or mouth of a coronary artery. The iodinated solution blocks the passage of x-rays. X-ray movie pictures taken during the injection of the contrast material allow the coronary arteries to be visualized. In other words, coronary arteries are not visible on x-ray film. However, they can be made temporarily visible by filling the coronary artery with a contrast solution that blocks x-ray. (Heartsite) 2) Discuss the rationale for catheterization. Cardiac catheterization allows the doctor to see the heart as it pumps blood. He is able to view the expansion and contraction of the chambers of the heart; the opening and closing of the heart valves; and the flow of blood through the coronary arteries. As compared to other diagnostic tests, cardiac catheterization provides more accurate and detailed information. This is...
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...Efficacy of Cardiac Rehabilitation A study conducted in Britain shows that the 40% mortality rate among men and 10% mortality rate among women between the ages of 45 and 65 years are due to coronary heart disease (Brennan, 1997). In Europe 22% of deaths are related to coronary heart disease. Most heart attack survivors are not receiving enough systematic help with rehabilitation, which results in anxiety, stress, depression and finally poor outcomes (Brennan, 1997). Living with these symptoms causes increased rate of morbidity and mortality after the infarction. One of the goals of cardiac rehabilitation is the reduction of morbidity and mortality through exercise training, dietary changes, smoking cessation and type A behavior modification. The second goal is amelioration of distress associated with cardiac pathology through the use of new coping strategies such as behavioral and cognitive techniques and stress management programs and anger control (Brennan, 1997). Exercise program is the most important intervention by researchers and clinicians. But the other form of intervention, like the effectiveness of smoking cessation programs, has received little attention. This article reviews the evidence for the efficiency of different forms of intervention that are focused on reducing distress and limiting risks during the post-infarction period. Exercise programs in cardiac rehabilitation studies prove their impact on the recurrence of myocardial infarction (Brennan, 1997)...
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...http://www.heart.org/HEARTORG/Conditions/More/CardiacRehab/What-is-Cardiac-Rehabilitation_UCM_307049_Article.jsp#mainContent WHAT IS CARDIAC REHABILATION? Cardiac rehabilitation (cardiac rehab) is a professionally supervised program to help people recover from heart attacks, heart surgery and percutaneous coronary intervention (PCI) procedures such as stenting and angioplasty. Cardiac rehab programs usually provide education and counseling services to help heart patients increase physical fitness, reduce cardiac symptoms, improve health and reduce the risk of future heart problems, including heart attack. WHO NEEDS CARDIAC REHABILATION? * Heart attack * Heart condition, such as coronary artery disease (CAD), angina or heart failure * Heart procedure or surgery, including coronary artery bypass graft (CABG) surgery, percutaneous coronary intervention (PCI), including coronary angioplasty (balloon angioplasty) and stenting, valve replacement, or a pacemaker or implantable cardioverter defibrillator (ICD) WHAT KIND OF SERVICES DO PROGRAMMES OFFER? * A medical evaluation to figure out your needs and limitations. The medical staff uses this information to tailor a rehabilitation program for you and help you set goals. * A physical activity program tailored to your needs. Training often starts in a group setting where your heart rate and blood pressure are monitored during physical activity. You may work with a physical therapist, exercise physiologist or other...
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...HEART RHYTHMS * 0.4 sec is the PR wave (it is actually the P-Q wave but called the PR wave) and it should be ≤ 0.20 sec. If it’s ≥ than that it indicates 1° heart block. * NSR: normal sinus rhythm, contraction originates from SA node and beats at 60-100 bpm * Sinus (atrial) Bradycardia: SA node discharges at < 60 bpm. TREATMENT is atropine and pacemaker if they become symptomatic. Usually the contractions are irregular but the same distance apart so they are irregular-regular * Sinus Tachycardia (atrial dysrhythmias): SA node discharges at > 100 bpm. Regular but fast; they won’t have heart block because the SA node is firing too rapidly. TREATMENT is BB or CCB to ↓ HR and BP * PAC (Premature Atrial Contraction): impulse travels across atria via abnormal pathway, creating a disturbed P wave. Contraction originates from ectopic focus in atrium other than the SA node. Caffeine and diet pills predispose people to these but they don’t adversely affect health. TREATMENT is none. * Atrial Flutter: atrial tachycardia resulting in recurring, regular sawtooth flutter waves. The ratio of atrial to ventricle contractions is 3:1. TREATMENT is synchronized cardioversion (like defibrillation but the less Joules, 150-200 vs 300, and you must push the “sync” button to synchronize the energy so as to not direct it onto the T wave and send the patient in V-fib) and ablations. * Valve Replacement: patient must be put on blood thinner afterwards and must be anticoagulated...
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...Unit 2. Assignment 1. Cardiac Conduction, Cycle, and Output Trace the flow of the blood through the heart: -Blood enters the Right Atrium -Travels through the Tricuspid Valve to the Right Ventricle -Pulmonary trunk and pulmonary arteries -Pulmonary capillaries aka the lungs is where blood loses CO2 and gains O2 -Pulmonary veins carry oxygenated blood -Blood enters Left Atrium -Enters the Left Ventricle via the Mitral Valve -Through the Aortic Valve into the Aorta and systemic arteries -Systemic capillaries, where blood loses O2 and gains CO2 -Superior/Inferior Vena Cava Physiology of Cardiac “Contraction” The action potential initiated by the SA Node travels along the cardiac conduction system and spreads out to excite the contractile fibers of the atria and ventricles. 1. Depolarization: When a contractile fiber is brought about by an action potential from the surrounding fibers, its Na+ channels open. Because the Na+ concentration is higher in the interstitial fluid this inflow produces a depolarization. 2. Plateau: A period of maintained depolarization. It is due to opening of Ca2+ channels in the sarcolemma. The increased Ca2+ concentration in the cytosol triggers contraction. The plateau phase lasts about 0.25 seconds. 3. Repolarization: The recovery of the resting membrane potential The electrocardiogram is used as a diagnostic tool by recording electrical charges that accompany the heartbeat. Like Billy the heartbeat kid =) As action potentials...
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...Christopher Dorasami The World Health Organization predicts that deaths due to cardiovascular disease (CVD) will increase around the globe from 17 million in 2008 to 25 million in 2030, (WHO,2012). CVDs are defined as all diseases of the circulatory system, including those of congenital origin, (AHA, 2010). Due to their high prevalence, CVDs impose a high social and financial burden on individuals, families and healthcare systems around the world. Surgical procedures like coronary artery bypass graft (CABG), balloon angioplasty, and valve repair and replacement are integral to the treatment of CVD, (WHO, 2013). Although these surgical procedures often improve survival rates, decrease symptoms and increase an individual’s functional ability (ACC/AHA 2004), surgery is not curative and individuals with chronic CVD remain at increased risk for coronary events(Foody et al. 2003, Hawks et al 2006). In addition to acute -operative care, these individuals must develop the knowledge and skills for self-management (Capewell S, 2008 & Vachenauer R. 2008). It is therefore important to encourage or enlist these patients in a health promotion programme post-surgery. The main aspects I would focus on include a behavioural change and an educational programme. Patient education programme The first aspect to be discussed with these patients will be based on: The concepts of atherosclerosis and its risk factors The reason for this is to help the patient understand...
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