august 31 HES-1823-004
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This 17 page Class Notes was uploaded by Jessica Notetaker on Friday September 4, 2015. The Class Notes belongs to HES-1823-004 at University of Oklahoma taught by Xin Ye in Fall 2015. Since its upload, it has received 39 views. For similar materials see Scientific Principles of Health and Disease in Health Sciences at University of Oklahoma.
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August 26 Intro to Health and Disease Chronic Disease Epidemiology Learning Objectives 0 Understand what constitutes being in a state of health and a state of disease 0 Know the de nition of physiology and pathology 0 Know the difference between a sign and a symptom 0 Know the de nition of a risk factor 0 Know the typical course of a chronic disease 0 Know the difference between prevalence and incidence Know what epidemiologists studies 0 Be able to identify three ways epidemiologists may analyze data What is Health 0 The World Health Organization WHO quotcompete physical mental and social well being and not merely the absence of disease or infirmity Google dictionary quotthe state of being free from illness or injuryquot 0 Wikipedia quotthe general condition of a person in all aspects What Factors Determine Health 0 Physical environment house community country 0 Lifestyle food choices exercise etc 0 Human biology Genetics 0 Healthcare services Physiology and Pathology 0 Physiology study of normal function Fundamental to understanding the pathology of chronic disease Study of normal functions 0 Pathology anatomic and physiologic deviations from the normal that constitutes disease study of what is not normal What is Disease 0 Disease is de ned as a pathological process having a characteristic set of signs and symptoms impairment of the normal state may effect the whole body or just parts may be cause by external factors viruses and bacteria or internal factors autoiminnine diseases Signs and Symptoms a symptom is an abnormal feeling noticed by a patient that indicated the presence of disease It is Subjective observed and not measured Ex Sore throat A sign is an objective medical fact that may be detected by a physical exam of a patient It can be measured Ex High blood pressure temperature Acute Vs Chronic Disease Acute brief or severe in effect Symptoms appear and change rapidly like the u Chronic long lasting or recurrent Develops and worsens over an extended period of time like heart disease Characteristics of Chronic Disease Risk Factor Non communicable can not be transferred from person to person Degenerative it gets worse Etiology the cause of the disease unclear or unidenti ed noncontagious origin Multiple risk factors Long latency period followed by a prolonged clinical course Doesn t resolve spontaneously Often associated with impairment and disability Complete cure unlikely a characteristic condition or behavior such as high blood pressure or smoking that increases the possibility of disease or injury Types of Risk Factors Modi able risk factors Changeable like smoking status and being overweightobese Nonmodi able rick factors not changeable such as genetic factors and physiologicmetabolic factors Course of Chronic Disease 1 2 3 4 5 Disease and Disease free state Asymptomatic biological changes symptoms are not yet detectable Morbidity clinical illness impairment and disability Comorbidity simultaneous and complex interaction of several disease at different stages of progression Mortality death Physical Activity o A normal physical activity level is the amount of physical activity obligatory for survival in a self sufficient environment 0 This high level of physical activity has shaped our normal function 0 Lack of physical activity sedentary behavior is largely responsible for the development of chronic diseases Exercise or Drugs for Treatment 0 Both exercise and drugs can be are used to treat various diseases Compared to drugs exercise is less potent but can prevent diseases 0 However the lack of a drug is not the usual cause of sickness Drugs restore function while exercise prevent activation of pathological process 0 Drugs may also produce negative side effects negative to health unlike exercise Primarv Secondarv Tertiarv Prevention 0 Primary prevention reducing incidence by eliminating causative agents before diseases ex Exercise 0 Secondary prevention detecting and correcting preclinical symptoms before overt clinical disease occurs Tertiary prevention reducing complications and morbidities of clinical disease 0 In the exam we will identify which one is which Epidemiology Epidemiology o Epidemiology is the study of the determinants occurrence distribution and control of health and disease in a de ned population used for planning and evaluating strategies to prevent illness helps guide the management of patients who have a disease Assessment of Causation How do we know what causes disease 0 Strength of association the stronger the better association does not Prove causation correlation does not equal causation Consistency of association similar relationship across multiple populations Eg smoking and lung cancer Temporality exposure precedes disease increase risk Biological gradient dose response relationship disease does an increase of possible cause increase risk of disease If you smoke more does it increase risk of lung cancer Plausibility biological possibility Does it make sense Coherence evidence control of confounding variables does drinking cause lung cancer The two are related But to determine cause you must control for smokers vs nonsmokers Incidence Rate Prevalence Mortalit incidence rate is number of new cases of a disease that develop within a speci ed period typically a year in a speci ed population it is expressed as the number of new cases of disease per year per 100000 population at risk Ex 500 cases per 342000 50034200000146 00146 X 100000 146 per 100000 people Prevalence is the total number of cases of a disease at a given time It is used as an estimate of how common a condition is within a population over a certain period of time Prevalence is a measure of all individuals affected by a disease at a particular time and it is in uenced by incidence rate and the persistence of disease Mortality is the relative frequency of deaths in a speci c population Challenges in Chronic Disease Control Monitor trends in chronic disease identify at risk group identify groups that do not respond well to intervention determining the effectiveness of prevention oriented interventions Effective communication of health risk one goal of Epidemiology is to control the disease Challenges in Chronic Disease Control reduction of health disparities in special populations poverty higher predisposition based on race crowded housing poor education poor access to health care exposure to hazardous environments racial discrimination development of supportive social and health policies increasing disability as a consequence of the progression of chronic disease Comorbidities increased rates of chronic disease and disability associated with aging of the US population Data Analysis and Interpretation My August 31 2015 Person analyses distribution of disease based on characteristics such as age race gender Place analyses distribution of disease based on geographic region Time analyses distribution of disease over time Epidemiology and chronic disease Course of chronic disease Risk factor Incidence and prevalence Data analysis person place and time Cardiovascular Anatomy amp Physiology Learning Objectives Know the major components of the cardiovascular system Know the path of blood ow through the heart Know the major structures of the heart Identify speci c arteries named in class Know the function and location of the valves in the heart Know what the electrocardiogram represents Identify the QRS complex and know what it represents Understand the components of the vascular system Know the differences between arteries and veins Know the determinants of blood pressure Know the meaning of systole and diastole 0 Understand cardiac output 0 Understand blood pressure terms and what they represent Cardiovascular svstem Components 0 The Heart distributes blood through the circulation Blood Vessels Arteries arterioles veins venules capillaries Blood carry nutrients ions wastes and gases The Heart Muscular organ enclosed in a brous sac weighs less than 05 kg 0 The Pump 0 During each cardiac cycle the heart contracts systole and relaxes diastole approximately 40 million beats per year at rest the heart pumps 1400 gallons of blood per day Heart Muscle the walls of the heart are composed primarily of muscle This muscle is 39striated Individual myocytes muscle cells cannot contract independently like skeletal muscle both atria contract together then both ventricles contract together Heart Anatomy 0 Right side of the heart receives deoxygenated blood from systemic circulation pumps deoxygenated blood to the lungs for oxygen through pulmonary circulation Left side of the heart receives oxygenated blood from the pulmonary veins pumps blood to the systemic circulation o Interventricular septum a thick sold muscular wall that separates the right and left sides of the heart 0 Both sides are composed of atrial and ventricular chambers atrioventricular AV valves separate the atria from the ventricles allow blood ow in one direction atriumgtventrice Ventricles 0 Receive and store blood while the ventricles contract thin walled saclike 70 of blood returning to the atria ows directly into the ventricles before the atrium contracts Atrial contraction forces the remaining blood into the ventricles Chambers whose contractions produce the pressure that drives blood though the pulmonary and systemic vascular systems and back to the heart Spiral and circular arrangements of bands of cardiac muscle quotwrings outquot blood from ventricles Valves in the Heart Atrioventricular AV valves separate the atria from the ventricles Pulmonary and aortic semilunar valves separate the right and left ventricle from the circulation respectively These valves prevent blood ow from moving in the opposite direction during the cardiac cycle Valve Position during Cardiac Cycle Event AV Valves Semilunar Valves R Tricuspid R Pulmonary L Mitral L Aortic Filling of Open Closed ventricle Building up Closed Closed pressure Expelling blood Closed Open a ma Pulmenarv valve pen Aertie valve epen USPS f39 aertit valve Wane valve ELDEE d Mitral valve eleaed Srv39lstnle leaps at A 39Pulmer39iarv valve pwlmenazrv valve f cleaed Right cerenarv artery Datia melithai at left and right 1auralvaryr arteries epening inte aertic Sinus eertic valve elased Euspa ef CherdaE quot aertic valve tendir ieae Tricuap id valve ipE Mitral valve epen Diaatele 0 Blood returning to the heart lls artia putting pressure against atrioventricular valves which are forced open 0 As ventriculars ll atrioventricle valve asps hang limply into ventriculars o Atria contract forcing additional blood into ventriculars Ventriculars contract forcing blood against atrioventricular valave cusps Atrioventricular valaves close Papillary muscles contract and chordae tendines tighten preventing valve asps from entering the atria As ventricular contract and intraventricular pressure rises blood is pushed up against semilunar valves forcing them open As ventriculars relax and tnraventricular pressure falls blood ows back from the arteries lling the cusps of semilunar valves and forcing them closed Heartbeat Coordination electro invents that trigger the heart 0 efficient pumping of blood requires that the atria contract rst followed almost immediately by the ventricles heart muscle contraction is triggered b an electrical stimulus depolarization 0 this begin at the SA node located in the right atrium Electrocardiooram an electrocardiogram ECG or EKG is the primary tool for evaluating the electrical events within the heart 0 many cardiac heart defeats alter the shape andor timing of the waves Summary of the Cardiac Cycle 0 Remember blood from right heart goes to the lungs o It has lower 02 content 0 Blood from left heart goes to the body o It has higher 02 content The Vascular System Arteries ow resistance tubes transporting blood to various organs most causes are oxygenated blood 0 Arterioles responsible for the pattern of blood ow distribution to various organs 0 Capillaries sites of nutrient and uid exchange between blood and tissue Veins lowresistance conduits for blood ow back to the heart 0 The entire vascular system has one structural component in common a smooth singlelayer of endothelial cells endothelium which lines the inner surface of the vessels Blood Pressure Arterial blood pressure re ects the combined effects of arterial blood ow per minute ie cardiac output and the resistance of that ow offered by the peripheral vasculature Determinants of Blood Pressure Arterial blood pressure is determined by blood volume how much blood is in the arteries Pressure increases with increases volume 0 Vascular resistance are the arteries more dilated or constricted Pressure increases with increases vascular resistance arterioles are the major site of vascular resistance major determinant of BP Cardiac Output 0 cardiac output stroke volume heart rate 0 heart rate beats per minute bpm Stroke volume amount of blood pumped out of the heart with each beat Blood Pressure Terms Systolic BP Diastolic BP Mean Pressure Pulse Pressure difference between systolic and diastolic pressure Svstolic Blood Pressure SBP 0 At rest in normotensive individual the highest pressure that is generated in the left ventricular averages 120 mm Hg SBP provides an estimate of the work of the heart and the force of blood exerted against the arterial walls Diastolic Blood Pressure DBP Pressure exerted against atrial walls during diastole of the cardiac cycle 0 Typically 7080 mm Hg Mean Arterial Pressure MAP 0 The average pressure during a cardiac cycle is not halfway value between SBP and DPB diastole lasts about twice as long as systole and this is taken into account MAP 23 DBP 13 SBP September 2 Hypertension and Heart Disease Leaning Objectives Know the criteria for hypertension Know the different types of hypertension Understand how cardiac output and total peripheral resistance affect blood pressure Understand the consequences of hypertension on the heart and blood vessels What is Hypertension Arbitrarily de ned as a level of blood pressure BP at which a person has an increased risk of developing a morbid cardiovascular event or will clearly bene t from medical therapy Associated with increased mortality and morbidity lncreases risk for heart disease stroke complications of advanced atherosclerosis Hypertension De ned Hype engon Systolic BP 3 140 mmHg or Diastolic BP 3 90 mmHg or 0 Taking antihypertensive medications El Prehypertension CI CI CI CI CI Systolic BP of 120139 mmHg Diastolic BP of 8089 mmHg Ideal Systolic BP lt120 mmHg Diastolic BP lt80 mmHg Types of Hypertension Scope Essential hypertension no identi able cause Accounts for 95 of cases and may be affected by genetics environmental factors diet Secondary hypertension caused by speci c defect such as renal disease or endocrine abnormalities Isolated systolic hypertension SBP gt 140 mmHg and DBP lt 90 mmHg Malignant hypertension rapid development of extremely high BP DBP usually gt 140 associated with papilledema White coat hypertension elevated BP associated with seeing health care personnel Risk Factors Hypertension affects more than 50 million Americans 65 of the population 6574 years old men slightly ore than women AfricanAmericans develop hypertension at an earlier age and it is more severe Age Family history Race Gender Smoking Serum cholesterol High sodium intake in some individuals Low potassium intake Physical inactivity Obesity Excessive alcohol intake Glucose intolerance Prediabetic Renin over activity Hvoertension thsioloov Increased BP must be due to a increase in cardiac output CO b elevated total peripheral resistance TPR c both Hypertension is frequently associated with normal CO and elevated TPR Hypertension Symptoms Usually no symptoms severe headache associated with the following symptoms indicated need for immediate medical treatment twedness confusion vision changes anginalike chest pain heart failure blood in urine nosebeed irreguar heartbeat ear noise or buzzing tinnitus Hypertension Pathophysiology untreated hypertension leads to premature death Most frequent cause of death is heart disease followed by stroke and renal failure Hypertension damages the endothelium which predisposes the individual to atherosclerosis The heart also has to do more work leading to left ventricular hypertrophy an important cause of heart failure Coronary Heart Disease CHD Learning Objectives understand the function of the coronary arteries and what occurs with atherosclerosis know the steps of progression for atherosclerosis know what ischemia and angina pectoris are understand what occurs during a heart attack know the risk factors for heart disease be able to identify the techniques used to identify a heart attack Coronary Arteries in addition to pumping blood the heart muscle needs its own blood supply The arteries supplying the myocardium are the coronary arteries Coronary Heart Disease Trends Coronary heart disease CHD is cause by narrowing of the coronary arteries that supply blood and oxygen to the heart AKA coronary artery disease CAD This causes insufficient blood supply to the heart Leading cause of death in US Mortality from heart disease decreased by 33 from 1990 to 2004 Ageadjusted death rate for men 50 higher than for women Sharp increases in mortality rate starting age 35 Caucasian Americans have highest mortality rates Risk increase with age regardless of other factors 55 of all myocardial infractions after age 65 85 of all related deaths after age 65 Development of CHD Atherosclerosis buildup of plaque in the major arteries of the body Underlying disease process for most cardiovascular disease Pathogenesis of atherosclerosis endotheia injury Lipids accumulate and precipitate formation of atheroma secondary brosis and calci cation Arterial endothelium progressively becomes thick rigid with irregular contour Atherosclerosis The beginning of atherosclerosis begins at a very early age Fatty streaks have been observed in 1 year old children Progression to an atheroma can occur at young ages 0 Formation of brous plaque occurs over a period of years to decades Manifestations of Heart Disease lschemia Angina Pectoris chest pain associated with ischemia 0 Myocardial infarction heart attack What is lschemia 0 Insuf cient blood ow to the heart 0 Results from severe narrowing of arteries 0 Most commonly occurs when heart demands extra oxygen Physical activity eating excitement or stress exposure to cold Myocardial infarction MI 0 during a myocardial infarction there is death of some heart muscle due to a blood clot causing a complete lack of blood ow atheroma ruptures causing a clot to form that stops blood ow occlusion Ml Signs and Svmbtoms 0 Pain is the most common symptom angina pectoris discomfort heaviness pressure aching burning numbness fullness squeezing or painful feeling usually in the chest May be felt in the left shoulder arms neck back orjaw Nausea and vomiting Faintness Sweating and clamminess 0 Women often experience vague symptoms fatigue shortness of breath nausea and vomiting abdominal pain Mvocardial infarction Complications Arrhythmias irregular heartbeat 0 Heart failure 0 lntracardiac thrombi o Pericarditis in ammation of the pericardium Cardiac rupture Papillary muscle dysfunction Ventricular aneurysm MI and Mortality Approximately 45 of those with an Ml will die within a year of their Ml faiure to recognize symptoms faiure to act on symptoms failure of timely transport to car facility 0 Many especially males deny symptoms 0 Average waiting time from the onset of symptoms to seeking medical assistance is two hours MI and mortality Sudden death from an MI is usually due to ventricular brillation uncoordinated ventricular contraction ineffective in producing ow Cardiopulmonary resuscitation CPR and de brillation is needed Tested over ventricular graph yl QFIS complex Sinoatriai H node Ventricular Atrioventricuiar depmarization node Ventricular Atrial depolarization repuleinzatmn P T Q PQ Interval S T i n S Sliegment l I l 39i39imes 0 02 04 06 08 QT Interval Copyright 2006 Pearson Education Inc publishing as Benjamin Cummings Modi able Risk Factors 0 Hypertension Lipid pro le blood markers high levels of low density lipoprotein high triglyceride levels ow levels of high density lipoprotein 0 Physical inactivity Smoking 0 Diabetes type II high blood sugar Cholesterol in the Blood 0 Cholesterol is a fatty waxy substance found in foods animal products and synthesizes by the body o It is essential for synthesizing certain hormones and is found in cell membranes o It is carried by lipoproteins in the blood 0 The lipoproteins are classi ed by density and an imbalance in the ratio of these lipoproteins facilitates atherosclerosis 0 Ratio of total cholesterol to HDL cholesterol is better predictor or CV risk than individual cholesterol levels Modi able Risk Factors Obesity 0 Central fat distribution quotbeer belly waist to hip ratio gt 10 for men or gt 08 for women 0 Dietary factors 0 Environmental smoke exposure 0 Excessive alcohol use and stress Diagnosis Electrocardiogram ECG lschemia andor Ml will cause changes in the shape and time of the ECG tracing Irregular heart rhythm arrhythmia May be transient ischemia or permanent Ml changes Coronary angiography Xray examination of the blood vessels or chambers of the heart Identify where in the artery narrowing or occlusion is occurring Blood analysis Enzyme levels in blood can determine if tissue damage has occurred Cardiac Imaging Provides information about heart wall motion and ejection fraction Exercise stress test Exercise increase the heart s work and uncovers coronary artery blockages that may not be detectable at rest During a treadmill or bike test heart rate breathing blood pressure ECG are recorded Chest pain andor ECG changes can indicate myocardial ischemia Myocardial perfusion imaging thallium scan during treadmill test can locate ischemic areas in myocardium