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Heart Anatomy of the Heart with 2D animation Note: by moving the mouse over the heart students will be able to hear the pronunciations. http://www.nucleuscatalog.com/cardiovascularsystem/search?search_category=3556 1 In a particular hospital’s Intensive Care Unit, patients always died in the same bed, on Sunday morning, at about 11:00 a.m., regardless of their medical condition. This puzzled the doctors and some even thought it had something to do with the supernatural. No one could solve the mystery as to why the deaths occurred around 11:00 a.m. on Sunday, so a Worldwide team of experts was assembled to investigate the cause of the incidents. The next Sunday morning, a few minutes before 11:00 a.m., all of the doctors and nurses nervously waited outside the ward to see for themselves what the terrible phenomenon was all about. Some were holding wooden crosses, prayer books, and other holy objects to ward off the evil spirits. Just when the clock struck 11:00, Pookie Johnson, the part-time Sunday sweeper, entered the ward and unplugged the life Support system so he could use the vacuum cleaner. 2 CIRCULATORY SYSTEM FUNCTIONS: Transport (nutrients like glucose and oxygen, wastes like CO2, and other substances like hormones) Immunity (leukocytes, antibodies) Temperature regulation (when you are cold, blood vessels constrict; when hot, they dilate) Penile erection 3 COMPONENTS OF CIRCULATORY SYSTEM Heart Blood Blood vessels (arteries, capillaries, veins) Lymph vessels and nodes 4 THE HEART The heart is the simplest organ in the body. It does only one thing: pumps blood. It beats 42 million times a year. It’s about the size of your clenched fist. Some of you have big fists, some have smaller fists. Its location is deep to the sternum. Take your left fist and place it on the sternum, then angle the bottom of your wrist to the left. When you say the Pledge of Allegiance, your hand is not over your heart. It’s not on the left, it’s in the center. 5 6 Location of the Heart in the Thorax The heart is located in the MEDIASTINUM, which is the central compartment of the thoracic cavity. 7 Membranes around the heart: PERICARDIUM 1) Parietal pericardium 2) Pericardial cavity 3) Visceral pericardium Visceral pericardium HEART 1) Epicardium (same as visceral pericardium) 2) Myocardium 3) Endocardium Parietal pericardium 8 PERICARDIUM Surrounds the heart (like a heart in baggie). The function is to lubricate the heart, so as it beats, it won’t rub against anything. The pericardium is divided into two layers with a space between them filled with fluid: PARIETAL PERICARDIUM PERICARDIAL CAVITY VISCERAL PERICARDIUM 9 PARIETAL PERICARDIUM This is actually the outermost layer of thoracic cavity. Two layers: SEROUS LAYER (simple squamous epithelium). Watery fluid. FIBROUS LAYER (moderately dense fibrous connective tissue) 10 VISCERAL PERICARDIUM (aka EPICARDIUM) Outermost layer of heart. It also has two layers: – SEROUS LAYER – FIBROUS LAYER 11 Layers of tissues around the heart: PERICARDIUM 1) Parietal pericardium 2) Pericardial cavity 3) Visceral pericardium Visceral pericardium HEART 1) Epicardium (same as visceral pericardium) 2) Myocardium 3) Endocardium Parietal pericardium 12 Structure of the Heart Parietal pericardium Pericardial cavity Visceral pericardium Myocardium of heart Endocardium of heart Inside chamber of heart 13 Figure 18.3 MYOCARDIUM The heart muscle itself (myocardium) is made of what tissue? Cardiac muscle. 14 ENDOCARDIUM The lining on the inside of the heart. Has two layers: ENDOTHELIUM (simple squamous epithelium that provides a smooth surface for the blood to pass by). If there are any irregularities in the smoothness of the endothelium (from inflammation or infection), a platelet could catch on it and start a blood clot. Loose connective tissue (deep to the endothelium) 15 PERICARDITIS Inflamed outer layer of heart, often from infection. Fluid accumulates in pericardial cavity, putting pressure on heart. Pericarditis can also be caused by damage to the blood vessels blood leaks into pericardial cavity pressure. Pericarditis can lead to pericardial friction rub, adhesions, and additional excess fluid in the pericardial cavity. It does NOT lead to a myocardial infarct (heart attack). 16 PERICARDITIS CARDIAC TAMPONADE: In severe cases of pericarditis, for example if there is a stab wound to the heart wall that causes fluid to exude into the pericardial cavity so much that the excess fluid compresses the heart and diminishes the heart’s ability to pump and it causes an irregular heart beat. An irregular heart beat is called arrhythmia. But don’t get this confused with arrhythmia that is caused from a problem with the SA or AV node. The irregular heart beat from cardiac tamponade is caused from fluid entering the pericardial cavity and putting pressure on the heart. Treatment is to stick a needle in the pericardial cavity and drain the fluid. 17 http://catalog.nucleusinc.com/generateexhibit.php?ID=68030&ExhibitKeywordsRaw=&TL=&A=2 ENDOCARDITIS More serious: Bacteria enter bloodstream from a break in the skin (dental procedures, IV drug abuse, catheter) damage to lining and valves blood clots. Those who already have damaged heart valves need prophylactic antibiotics before any procedure, even teeth cleaning. Don’t get endocarditis (bacterial infection leading to blood clots) mixed up with pericarditis (bacterial infection or injury which can lead to cardiac tamponade). 18 THE HEART IS TWO PUMPS: LEFT AND RIGHT LEFT PUMP: From lungs to body RIGHT PUMP: From body to lungs 19 The Pulmonary and Systemic Circuits 20 Figure 18.1 Heart Chambers • Each pump has two types of chambers: ATRIUM and VENTRICLE Left Atrium Right Atrium Right Ventricle Left Ventricle 21 Blood Flow Deoxygenated blood from body enters the RA through the superior and inferior vena cava. It pours through the TRICUSPID (RIGHT AV) VALVE into the right ventricle. Right atrium contracts, pushes blood into the right ventricle ventricle expands, then contracts with force. To prevent the blood from going back up into the atrium, need a valve. 22 Blood Flow • Blood comes from the superior or inferior vena cava, into the right atrium, past the tricuspid valve, into the right ventricle. It then goes past the pulmonary semilunar valve, and into the pulmonary arteries. SVC RA Pulmonary arteries Pulmonary Semilunar valve Tricuspid valve RV IVC 23 VALVES Valves are like a swinging door that can only open one direction. But you can push against this door, since it’s only tissue. But if you tie a rope to the doorknob, it won’t be able to go the wrong way. The ropes are called CHORDAE TENDONAE, (“heart strings”) which are anchored to pieces of myocardium called PAPILLARY MUSCLES. The contraction of the papillary muscles pulls on the chordae tendonae to close the valves, preventing a PROLAPSED VALVE (turned inside out). 24 Valves 25 Figure 18.9a Function of the Atrioventricular Valves 26 Figure 18.9b Heart Valves – Valve Structure 27 Figure 18.8a Trabeculae carneae (spongy meat) Trabeculae carnae are masses of irregular spongy tissues which project from the inner surface of the right and left ventricles. The purpose of the trabeculae carneae is to prevent suction that would occur when the ventricles contract and their inside surfaces touch each other. If the surface was flat, it would stick and impair the heart's ability to pump efficiently. The trabeculae carneae also serve a similar function to papillary muscles in that their contraction pulls on the chordae tendineae, preventing prolapsed mitral (bicuspid) and 28 tricuspid valves. Trabecula Carnae 29 What is an artery? An artery is a vessel that carries blood AWAY from the heart. It does not matter if it is oxygenated or deoxygenated blood. A vein is a vessel that carries blood TOWARD the heart. It does not matter if it is oxygenated or deoxygenated blood. 30 Blood Flow With the ventricular contraction, blood can go only one way: into the PULMONARY ARTERY (one of the few arteries with deoxy blood). When the ventricles relax, the PULMONARY SEMILUNAR VALVE closes to prevent blood from going from the pulmonary artery back into the right ventricle. SVC Pulmonary arteries Pulmonary veins RA Pulmonary semilunar valve Tricuspid valve RV IVC 31 Function of the Semilunar Valves 32 Figure 18.10a, b Blood Flow When the ventricles relax, the PULMONARY SEMILUNAR VALVE closes to prevent blood from going from the pulmonary artery back into the right ventricle. Do the semilunar valves have a chordae tendonae? No; the blood is not being forced back (with a contraction), it just falls back with gravity, so there’s not as much pressure. 33 Blood Flow • Blood then goes into lungs, gets oxygenated, and returns on the left side through the PULMONARY VEINS (one of the few veins with oxy blood), into the LEFT ATRIUM. Pulmonary arteries Lungs Pulmonary veins LA Tricuspid valve Bicuspid (mitral) valve LV 34 Blood Flow From the LEFT ATRIUM, it goes through the MITRAL VALVE (BICUSPID VALVE) into the LEFT VENTRICLE(there are also chordae tendonae here), which contracts. Therefore, the left ventricle is the chamber which is responsible for generating the largest pressure upon contraction. Lungs Pulmonary arteries Pulmonary veins LA Tricuspid valve Bicuspid (mitral) valve LV 35 Mitral Valve The mitral valve gets its name from being the shape of a Bishop’s hat, called a mitre. 36 Blood Flow • The blood then goes past the AORTIC SEMILUNAR VALVE, into the AORTA, and out to the body. Aorta The semilunar valves are located between the ventricles and the great arteries. SVC Pulmonary arteries Pulmonary veins LA RA Pulmonary semilunar valve Bicuspid valve Tricuspid valve RV LV IVC 37 38 VALVES: “Try before you Buy” TRICUSPID VALVE BICUSPID VALVE (MITRAL VALVE) PULMONARY SEMILUNAR VALVE AORTIC SEMILUNAR VALVE Structures associated with tricuspid and bicuspid valves CHORDAE TENDONAE PAPILLARY MUSCLES 39 Blood Flow Deoxy blood sup/inf vena cava R atrium tricuspid valve R ventricle pulmonary semilunar valve pulmonary artery lungs pulmonary veins Left atrium mitral (bicuspid) valve Left ventricle aortic semilunar valve aorta rest of body. Aorta SVC Pulmonary arteries Pulmonary veins LA RA Pulmonary semilunar valve Bicuspid valve Tricuspid valve Aortic semilunar valve RV IVC LV 40 Heart Chambers 41 Figure 18.5e Heart Chambers 42 Figure 18.5b Inferior View of the Heart 43 Figure 18.5d 44 Atrial septum Right atrium Right ventricle Apex Interventricular septum Left atrium Left ventricle 45 Aortic semilunar valve Mitral (bicuspid) valve Cordae tendonae Trabeculae carnae Papillary muscles 46 Mitral Valve Stenosis • If there is stenosis (blockage) of the mitral valve, where will the blood back up into? • Answer: the pulmonary circulation. This is one disorder where the patient might cough up blood. Pulmonary arteries Lungs Pulmonary veins LA Tricuspid valve Bicuspid (mitral) valve LV 47 HEART BEATS The pressure of blood against blood vessel walls is called blood pressure. Blood pressure is recorded systole over diastole. Normal resting blood pressure is said to be 120/80. When blood pressure is too high, it is called HYPERTENSION. The sound your heart makes when it is beating is the sound of the blood hitting the valves after they are closed. The heart normally beats at a rate of 60-80 beats per minute. A faster (tachycardia) or slower (bradycardia) heart rate is an indication of a problem. 48 HEART BEATS All four chambers cannot contract at the same time. Only two at a time can contract. The atria contract together, then the ventricles. The left and right ventricles contract at the same time = SYSTOLE. When the ventricles are relaxed = DIASTOLE. At which stage do the atria contract? Diastole. 49 HEART BEATS SYSTOLE: Ventricles contract Atria relax DIASTOLE: Ventricles relax Atria contract 50 HEART BEATS Start of Systole: Closing of valves (tricuspid and mitral) causes blood to hit the valves, making a sound. Systole of the ventricle means that this chamber is contracting. End of Systole: Closing of semilunar aortic and pulmonary valves causes blood to hit the valves, making a sound 51 HEART BEATS Lub-Dub is the sound of the blood hitting the closed valves. Start of Systole: Closing of the large valves (tricuspid and mitral) = “LUB” sound from blood hitting them. End of Systole: Closing of semilunar valves (aortic and pulmonary)= “DUB” sound (“Dub”) from blood hitting them. 52 Heart Sounds 53 Figure 18.11 Valve Problems HEART MURMUR If the valve leaks, it doesn’t close all the way “Lub-squirt” Most murmurs are benign; fairly common, esp. in babies and some adults. 54 Abnormal Heart Sounds Friction rubs Gallops Murmurs • http://www.wilkes.med.ucla.edu/intro.html 56 Valve Problems • PROLAPSED VALVE is more serious. The valve turns all the way inside out. • Mitral valve is most likely to prolapse because it pumped the hardest. See how much thicker the left ventricle is? Mitral Valve Prolapse is the most common heart valve disorder. Might need artificial valve. 57 Artificial Valve • The Sapien Transcatheter Heart Valve (THV) is made of cow tissue and polyester supported with a stainless steel mesh frame. To replace the diseased valve, the Sapien THV is compressed into the end of a long, thin, tube-like device called a delivery catheter, which is slightly wider than a pencil, and inserted into the femoral artery through a small cut in the leg and threaded to the site of the diseased valve. 58 Porcine (Pig) Valve 59 60 61 What controls the heart beat? There is a small region in the right atrium = SA NODE (Sino-atrium node) = pacemaker of the heart. Its job is to speed up or slow down the heart rate as needed. SA node sends an electrical signal (action potential) to the AV NODE (atrioventricular node) atrium contraction then the signal pauses before the signal is transmitted to both ventricles (atria are now relaxing) sends the action potential to all parts of the ventricles so they can contract. 62 Conducting System PLAY Intrinsic Conduction System 63 Figure 18.12 Heart Beats The heart does not need a nerve to stimulate it to contract; rather, specialized heart cells can spontaneously start an action potential that spreads to depolarize the rest of the cardiac muscle cells. These are the specialized cells: A. SA node B. AV node C. Bundle of His (AV bundle) D. left and right bundle branches E. Purkinje fibers 64 Heart Beats This is the order in which these specialized cells function: First the Sinoatrial (SA) node starts an action potential which causes the atria to depolarize. This depolarization will then reach the AV node at the bottom portion of the right atrium and there is a delay here because these cells are so small in diameter. Another delay in the transmission of the depolarization at the bundle of His (AV bundle) because these special heart cells travel through the atrioventricular septum which is non-conductive fibrous connective tissue. The Bundle of His slows down the electrical pathway to give the atria a chance to finish contacting. Next, the depolarizing event travels through the left and right bundle branches, found in the interventricular septum, to finally arrive at the Purkinje fibers in the lateral walls of the myocardium of the ventricles. 65 Conducting System PLAY Intrinsic Conduction System 66 Figure 18.12 67 Impulse Pathway • SA node • AV node • Bundle of His (conduction slows down here because this area is fibrous connective tissue, not muscle cells. This gives the atria time to contract before the ventricles • Right and left bundle branches on the IV septum • Purkinje fibers on the lateral wall of the ventricles…now they contract http://www.phschool.com/science/biology_place/biocoach/cardio1/electrical.html 68 EKG 69 Problems ARRHYTHMIA Problem with the SA or AV node improper heart beat. Treatment is medicines or a pacemaker. 70 Fibrillation FIBRILLATION is when the heart beat is not really present…it just vibrates. A heart in fibrillation does not contract rhythmically; it just quivers without pumping blood. The ventricles are unable to pump blood efficiently due to rapid, random contraction of cardiac muscle fibers. The muscle doesn’t contract as a unit. 71 FIBRILLATION Treatment is defibrillate with electric shock closes down heart maybe it will restart. This machine is never used when someone’s heart is beating with a lub-dub sound, even if it is irregular, because it causes the heart to stop. Whatever caused the fibrillation in the first place is not treated, so it may not work, but it’s worth a try! Most large public facilities have them. There are several on most college campuses. Disneyland has one every 100 yards. 72 Fun Fact If someone with a pacemaker dies, does their heart keep beating? No. A pacemaker can only stimulate an irregularly beating heart, not a dead one. The pacemaker would almost certainly be triggered, since it would detect the absence of a regular heartbeat, but it would be to no avail. 73 THE HEART NEEDS ITS OWN BLOOD/O2 The endocardium gets plenty of O2 from the blood cells that touch this layer as they travel through the heart, but the oxygen does not diffuse all the way into the myocardium, which is a deeper layer. 74 THE HEART NEEDS ITS OWN BLOOD/O2 Therefore, the myocardium needs its own blood supply by CORONARY ARTERIES and VEINS. They are on the surface of the heart, and there are four of them. 75 Coronary Vessels 1) Right coronary artery The left one is too short to be counted 2) Circumflex artery 3) Anterior Interventricular artery 4) Posterior Interventricular artery The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart and delivers it into the right atrium. 76 Heart Chambers 77 Figure 18.5b Inferior View of the Heart 78 Figure 18.5d THE HEART NEEDS ITS OWN BLOOD/O2 The more you do aerobic exercise, the more branches of these arteries are formed between themselves (anastomosis), and the better the blood supply to the heart. When blood vessels fuse together where they meet it is said that they ANASTOMOSE. This is a safety mechanism that allows blood to get through if one of the vessels gets clogged. People who exercise have the same number of heart attacks as those who don’t, but they tend to survive them because they have more anastomoses. 79 THE HEART NEEDS ITS OWN BLOOD/O2 If one of the four coronary arteries becomes clogged, ISCHEMIA (lack of oxygen) to part of the heart muscle will result. This is a painful condition, and the pain of it is called ANGINA (heart pain). If nothing is done immediately to increase the blood flow, the myocardial tissue can die; this condition is called a myocardial infarct (HEART ATTACK). VIDEO http://www.dnatube.com/video/1966/Myocardial-Infarction 80 Diagnosis of MI Abnormally high cardiac enzymes in the blood is evidence of a heart attack. The most commonly tested cardiac enzyme is creatinine phosphokinase (CPK isoenzymes test). Creatinine phophokinase is present in heart, brain, and skeletal muscle, so having it elevated may only mean the person was physically active recently. However, these enzymes can be detected as separate types: CPK-BB (CPK-1) - concentration in the brain and lungs (caused by stroke, or lung injury) CPK-MM (CPK-3) - found mostly in the skeletal muscle. CPK-MB (CPK-2) - found mostly in the heart (also called Troponin-I ) CPK-2 level increases after three to six hours following a heart attack, peak within 12- 24 hours (or longer depending on the severity of the heart attack) and return to normal level 12 - 48 hours after tissue death. Confirmation of heart attack when CK-MB is elevated and the ratio of CK-MB to total CK (relative index) greater than 2.5 - 3. 9 A hospital patient can be diagnosed with a normal electrocardiogram but have elevated creatinine phosphokinase (CPK-MB) elevation indicating a heart attack. 81 Angina Attack People who have an angina attack can take nitroglycerine as a tablet under the tongue that dissolves quickly. This medicine will dilate the blood vessels. 82 Weird ER Story A 28-year old male was brought into the ER after an attempted suicide. The man had swallowed several nitroglycerine pills and a fifth of vodka. When asked about the bruises about his head and chest he said that they were from him ramming himself into the wall in an attempt to make the nitroglycerine explode. 83 Coronary Bypass When a person has their first angina attack, the doctor will order an ANGIOGRAM to look for a narrowing in an artery, especially in one of the coronary arteries. 84 ANGIOGRAM An ANGIOGRAM is a procedure to inject dye into the arteries and x-ray to see if there is narrowing (sclerosis) of a vessel. This can be done anywhere in the body that is of interest, but frequently it is done to check the coronary arteries. 85 Angiogram 86 ANGIOPLASTY If an artery is too narrow, an ANGIOPLASTY can be performed to open it up. This involves sticking a balloon into the artery and inflating it, causing the vessel to enlarge a little to increase blood flow. This can be done anywhere in the body, but is frequently done in coronary arteries. 87 Angioplasty Stent Video 1 Stent Video 2 88 Scientists develop a gel that mimics mollusc glue to coat the insides of blood vessels. http://www.thescientist.com/?articles.view/articleNo/3 4766/title/Mimicking-Mussels/ 89 Coronary Bypass If a coronary artery is found to have a severe blockage, they can do a CORONARY BYPASS. In this procedure, the doctor takes another blood vessel graft (from the greater saphenous vein in the thigh) and sews it in around the blockage. For double or triple bypasses, that’s how many vessels are affected. 90 Blood Supply to the Heart 91 Figure 18.14 R. common carotid artery R. subclavian artery Brachiocephalic trunk Aorta Superior vena cava Pulmonary trunk Auricle (ear-shaped flap on the right atrium R. Coronary artery Anterior interventricular artery Left common carotid artery Left subclavian artery L. Pulmonary artery Pulmonary veins L. Coronary artery Circumflex artery 92 TERMS ANGINA: heart pain, usually caused from not enough oxygen to the myocardium (ischemia) ISCHEMIA: lack of blood/oxygen MYOCARDIAL INFARCTION: heart attack (cardiac tissue death) from a clot in coronary artery, causing ischemia (lack of oxygen), which causes angina (heart pain). 93 HEART ATTACK Not enough blood to the heart’s myocardium layer MILD ISCHEMIA severe pain: ANGINA (angina pectoris) Treatment is nitroglycerine to open arteries Complete blockage not enough O2 to that area = SEVERE ISCHEMIA that part of heart muscle dies = MYOCARDIAL INFARCTION. Heart muscle never regenerates. If a large area dies, person will die. 94 HEART ATTACK What are symptoms of a heart attack? Chest pain, pain down left arm, shortness of breath, nausea, tight pressure in chest. A common symptom is death. 50% of first heart attacks are fatal within 2 hours. If a person receives good treatment in the first 2 hours, they are more likely to survive. About ¾ million people die each year from heart attacks. 95 HEART ATTACK A drug that can stop heart attacks in progress by dissolving clots is t-PA (also used to dissolve clots that are causing a stroke) Angioplasty is a surgical procedure to clean out a clogged artery. A beta blocker is a drug that slows down the heart rate (used for tachycardia) Aspirin reduces blood clot formation Nitroglycerine dilates the coronary arteries so more blood can get in. 96 Heart Medicines t-PA (dissolves blood clots) Beta-blockers (slows heart rate) Aspirin (prevents blood clots) Nitroglycerine (dilates coronary arteries) 97 Fun Fact If a person takes an aspirin once a day to prevent clots or a heart attack, they should take it at NIGHT. Aspirin has a half life of 24 hours, so its effect is strongest in the morning. Most heart attacks occur in the morning! 98 Bayer has new Quick Release crystals that dissolve faster in your mouth. 99 FUN FACTS ABOUT THE HEART --According to German researchers, the risk of heart attack is higher on Monday than any other day of the week; there is more stress on that day. --A Giraffe’s heart is 2 feet across. --Heart disease is a big killer, but what animal causes the most human deaths? Sharks kill 10 people per year. 100 people die each year from being stepped on by cows. 100 --But a cow is not the world’s most deadly animal, which kills the most people. What IS the world’s most deadly animal? 101 --The whitetail deer causes the most deaths because of all the traffic accidents they cause. 102 Blue Whale Heart Size 103 Videos Heart 5 mins Capillaries 3 mins 104 CIRCULATORY DISEASE CONDITIONS The leading cause of untimely death in the Western countries of the world is cardiovascular disease. There are several hereditary factors that influence whether a person will get cardiovascular disease: 1. family history of heart attack 2. gender (males are high risk) 3. race/ethnicity (African Americans high risk) 105 CIRCULATORY DISEASE CONDITIONS Whether or not you have a hereditary factor, there are some things you can do to prevent heart disease with diet and exercise. Included in this is knowing your cholesterol level, lowering your LDL intake, use olive and canola oil rather than butter/cream. Some studies also suggest that antioxidant vitamins (A, E, and C) may help, but remember that too much vitamin A and E cause a lot more harm to the liver than good to the circulation. 106 Causes of High Blood Pressure Both arteriosclerosis and atherosclerosis cause high blood pressure. ARTERIOSCLEROSIS (hardening of the arteries): caused by a build-up of calcium deposits in the artery wall; artery cannot expand with blood surges. The blood vessel becomes hard like a rock; it can’t expand or contract, causes increase in blood pressure. Tends to be hereditary. Diet and exercise don’t help this much. 107 Areteriosclerosis 108 Causes of High Blood Pressure ATHEROSCLEROSIS (a build-up of fat in the arteries): caused from eating fatty food narrowing of artery Spasm shut or blood clot. 109 Atherosclerosis 110 EMBOLISM When fat builds up in a lump in one place, it is called a PLAQUE. It causes the lumen to narrow, restricting blood flow. If this fatty plaque breaks off and travels in the bloodstream, it is now called an EMBOLISM. An embolism can also be made of blood instead of fat. 111 Terms Plaque: lump of fat, usually artery Thrombus: blood clot, usually vein Embolism: when a piece of fat or blood breaks off and travels. 112 How a thrombus becomes embolism If a platelet catches on a piece of this fat, it can start a blood clot (thrombus). If a piece of the clot (thrombus) breaks off and enters the circulation, it is now called an embolism, it can lodge in a smaller blood vessel and block the oxygen to all the tissue past that point, and the tissue dies. 113 Blockage of blood vessel If the embolism lodges in the coronary arteries myocardial infarct (Heart attack). If the embolism lodges in an artery in the brain stroke If the embolism lodges in the lungs pulmonary embolism 114 Pulmonary Embolism 115 VENTRICULAR FIBRILLATION Even a small clot can be a problem. If it happens to enter the interior of the heart and lodge in the wall of the atrium, it can block the conduction of the signal of the AV node VENTRICULAR FIBRILLATION. 116 ANEURYSM High blood pressure is due to high pressure of blood against the walls of the blood vessels; the blood vessels compensate by developing a thicker wall. The vessels can no longer expand during systole, so the vessel gets thicker and thicker, and the blood pressure goes up more. If the blood pressure gets too high, an ANEURYSM can form, which is a weakening in the wall of the blood vessel, causing it to expand like a balloon. 117 ANEURYSM Thus, an aneurysm is a sac-like outpouching of an artery. If it ruptures, it’s very dangerous. The aorta is the first artery that leaves the heart. It is under high pressure, so it is susceptible to getting aneurysims that can easily rupture; you’ll be dead in three heart beats. Can also get aneurysms in the brain that can rupture and causes stroke. Aneurysms often have no symptoms. 118 Coronary artery disease terms Coronary artery disease Atherosclerosis – fatty deposits Angina pectoris – chest pain Myocardial infarction – blocked coronary artery Silent ischemia – lack of blood flow that happens to not cause any pain or other symptoms until it hits a critical threshold; leads to an unexpected heart attack. Stroke – ruptured blood vessel or blood clot in the brain. The proper medical term for a stroke is a Cerebral Vascular Accident (CVA) 119 Clarification of Terminology A blocked artery can occur anywhere in the body. A blocked CORONARY artery is what causes a heart attack. The coronary arteries are those that supply the myocardium of the heart. Ischemia is a lack of oxygen from lack of blood flow. It can occur anywhere in the body. When there is ischemia in your leg from sitting on it wrong, it is from lack of blood flow to the muscles of your leg. it gives you a pins and needles feeling but it will repair itself when you restore the blood flow. 120 Clarification of Terminology When there is ischemia in the heart, it is from a lack of blood flow to the myocardium of the heart (the actual muscle tissue of the heart). The only arteries that supply the heart are the coronary arteries. Therefore, ischemia in the heart can only be caused by some blockage in at least one coronary artery. In this case, a heart attack will ensue because ischemia in the heart causes permanent damage quickly. Fortunately. there are four coronary arteries, so many people can survive a heart attack if not all of them are blocked. That's why some heart attacks are called "mild heart attacks"; only a small piece of the myocardium died off and the heart is able to keep beating properly. 121 Predictors of Heart Attack High Blood Pressure High Cholesterol Large Waist Size 122 Predictors of Heart Attack Normal blood pressure is 120/80. Pre-hypertension is 120 to 139 (systolic) and/or 80 to 89 (diastolic). Hypertension – also known as high blood pressure -- is 140 or higher (systolic) and 90 or higher (diastolic). One in three adults in the U.S. has high blood pressure or prehypertension. 123 Who Does Hypertension Effect? ■ Hypertension is the most common primary diagnosis in America. ■ 35 million doctor visits result in the primary diagnosis of hypertension. ■ 50 million Americans have high blood pressure. ■ 1 billion worldwide have Hypertension ■ 7.1 million deaths per year may be due to hypertension. What is considered Hypertension ■ An average of two or more blood pressure readings are done to determine blood pressure for hypertension diagnosis. ■ On each of two or more office visits. Determining Blood Pressure ■ The equipment should be regularly inspected and validated. ■ The operator should be trained and regularly retrained. ■ The patient must be properly prepared and positioned and seated quietly for at least 5 minutes in a chair. ■ The auscultatory method should be used. ■ Caffeine, exercise, and smoking should be avoided for at least 30 minutes before BP measurement. ■ An appropriately sized cuff should be used. Based on Blood pressure… When should you see the doctor? Pre-hyertension ■ Prehypertension is not a disease. It is a designation for individuals at high risk of developing hypertension. They are not a candidate for drug therapy. ■ Should be strongly advised to practice lifestyle modification ■ Those with pre-hypertension who also have diabetes or kidney disease, could be eligible for drug therapy if lifestyle modification fails to reduce their BP to 130/80 mmHg or less. Types of Hypertension ■ Primary Hypertension: also known as essential Hypertension. accounts for 95% cases of Hypertension. No universally established cause known. • Secondary Hypertension less common cause of Hypertension ( 5%) Secondary to other potentially primary causes. Complications of Prolonged Uncontrolled Hypertension ■ Changes in the vessel wall leading to vessel trauma and arteriosclerosis throughout the vasculature ■ Complications arise due to the “target organ” dysfunction and ultimately failure. ■ Damage to the blood vessels can be seen on fundoscopy. Progressive States of Hypertension ■Accelerated Hypertension: No progressive target-organ dysfunction. (Accelerated Hypertension) ■Malignant Hypertension: Progressive end-organ dysfunction. Target Organs ■CVS (Heart and Blood Vessels) ■The kidneys ■Nervous system ■The Eyes Effects On CVS ■Ventricular hypertrophy, dysfunction and failure. ■Arrhythmias ■Coronary artery disease, Acute MI ■Arterial aneurysms Effects on The Kidneys ■Glomerular sclerosis leading to impaired kidney function and finally end stage kidney disease. ■Ischemic kidney disease especially when renal artery stenosis is the cause of HTN Nervous System ■Stroke, intracerebral and subaracnoid hemorrhage. ■Cerebral atrophy and dementia How to diagnose Hypertension and severity ■ General Examination for reading of blood pressure ■ Neurological assessments ■ EKG ■ Routine Labs : ■ ■ ■ ■ Urinalysis. Blood glucose and hematocrit HDL cholesterol, LDL cholesterol, and triglycerides. urinary albumin excretion. albumin/creatinine ratio. Drug Therapy To combat hypertension, various types of drugs may be used such as: • • • • • • Diuretics Beta Blockers Ace Inhibitors Calcium Channel Blockers Alpha Blockers and 5 other classifications of drugs Predictors of Heart Attack: Cholesterol levels you DON’T want Triglycerides of greater than 150 mg/dL. Total cholesterol higher than of 200 mg/dL. HDL ("good" cholesterol) lower than 50 mg/dL (females) or 40 mg/dL (males). LDL (“bad” cholesterol) higher than 100 Unless you have other major risk factors, like diabetes, you want your LDL closer to 70. The new standards are to look at the ratio of Total Cholesterol to HDL; it should be less than 5. Example: 200/50 = 4 (healthy). Estrogen in women contributes to higher HDL levels, which decrease after menopause. Is your boss watching your cholesterol? http://fxn.ws/RwNGS1 138 Left = Normal Right three = 44 years old, total cholesterol of 464, triglycerides are 3500 139 Predictors of Heart Attack FEMALES: waist size more than 35 inches MALES: waist size more than 40 inches Measure around your belly button. If patients lose even 1 inch off their waist, there are improvements in all the other heart health numbers If they gain even 1 inch, there is a worsening in those numbers. It's a much better indicator of heart health than weight. 140 Other Heart Conditions Congestive Heart failure Progressive weakening of the heart Blood backs up into lungs (may cough up blood) Cannot meet the body’s demands for oxygenated blood Hypertrophic cardiomyopathy Congenital condition where the walls of the left ventricle are so thick that the lumen is too small to hold much blood. 141 Disorders of Conduction Ventricular fibrillation Rapid, random firing of electrical impulses in the ventricles of the AV node Atrial fibrillation Rapid, random firing of electrical impulses of the SA node 142 Most Common Heart Problems Atherosclerosis Ventricular fibrillation Congestive heart failure Hypertrophic cardiomyopathy 143 FUN FACT Can you die from laughing? It's certainly possible to die while laughing -probably by choking on something. But laughing is actually very good for you. According to the Indiana University School of Medicine, laughing helps relax tense muscles, lowers blood pressure, and even burns calories. People with heart disease are 40% less likely to laugh in a given situation than people without heart disease. The key here seems to be stress reduction; stress impairs the production of endothelial cells, which form a protective lining in our blood vessels. A weak endothelium can lead to hardened arteries and, quite literally, a hardened heart. 144 EMBRYONIC DEVELOPMENT OF THE HEART The heart is the most common site for congenital defects (those one is born with). During fetal life, the mother provides the oxygen and nutrients through the placenta. If there is a problem with the baby’s heart, it is not a problem until birth, although it can be detected by ultrasound. 145 EMBRYONIC DEVELOPMENT OF THE HEART • The earliest heart chambers 146 Figure 18.16a, b The Heart Throughout Life 147 Figure 18.16c–e EMBRYONIC DEVELOPMENT OF THE HEART At 28 days (two weeks after a woman misses her period), the human heart first starts to beat and pump blood in the embryo (at the end of the fourth week). You have to stop smoking and drinking before you get pregnant. By the time you know you’re pregnant, it’s too late for the baby’s heart. 148 Fetal Heart Where is the fetus getting the oxygen during the nine months in the womb? The mother, not the lungs of the fetus. So there’s no sense in sending half of the fetus’s body’s blood to the lungs for oxygen. 149 Fetal Blood Vessels ► When oxygenated blood from the placenta is carried to the fetus by the umbilical vein, where does it go? ► About half of this blood enters the inferior vena cava of the fetus, while the other half enters the liver of the fetus. ► The blood in the inferior vena cava empties into the right atrium of the heart, and then moves directly into the left atrium instead of going to the lungs. ► Blood moves from the right atrium to the left atrium by going through a hole called the foramen ovale. ► Thus, blood bypasses the pulmonary circulation 150 (does not go to the lungs of the fetus). missinglink.ucsf.edu 151 FORAMEN OVALE ►There is a foramen ovale in the skull and another one in the heart, between the two atria. The foramen ovale in the heart normally closes shortly after birth, and is then called the FOSSA OVALIS. ►A ‘blue baby” has low oxygen levels in the blood that may be due to failure of the foramen ovale to close at birth. ►When the foramen ovale fails to close, it is called a patent foramen ovale. ►Patent (Pay-tent) means “open” 152 Foramen Ovale 153 kardiol.com Fetal Circulation ►Not all of the blood in the right atrium goes through the foramen ovale to bypass the pulmonary circulation, because the lung tissue needs some oxygen. ►Therefore, some of the blood entering the right atrium does not pass directly to the left atrium through the foramen ovale, but enters the right ventricle (same as an adult) and is pumped into the pulmonary artery and goes to the lungs. 154 Fetal Circulation ►However, the lung tissue of the fetus do not need that much blood, so there is a special connection between the pulmonary artery and the aorta in the fetus, which directs most of this blood away from the lungs and back to the aorta. ►This connecting blood vessel is called the ductus arteriosus. 155 kvitters.com Adult Fetus 156 Changes at Birth ►At birth, there is an immediate change. Half of the blood needs to go to the lungs. ►At the first breath, a flap closes over the foramen ovale, and a muscle around the ductus arteriosus constricts, causing instant closing, and seals shut permanently. ►The foramen ovale is now called the fossa ovalis, and the ductus arteriosus is now called the ligamentum arteriosum. 157 Ductus Arteriosus (fetus only) 158 Ligamentum arteriosum (after birth) 159 Patent Foramen Ovale ►When a baby has not started walking, it doesn’t need as much oxygen, so a patent foramen ovale might not be noticed until they start to walk and run at age 2-3. ►However, every time the baby cries, it might turn blue. ►A patent foramen ovale can be surgically closed by going through the blood vessels without cutting into the heart tissue. ►A patent foramen ovale in an adult is just a tiny opening and can be heard as a heart murmur. ►You can also have a patent ductus arteriosus, which also requires surgery. 160 Heart Deformities More significant problems: interventricular septal defect (between right and left ventricle). Requires open heart surgery. 161 Congenital Heart Defects 162 Figure 18.17a, b Artificial Heart • If heart is totally deformed, need transplant. 163 Fetal Circulation ►In the fetus, there is a branch off the internal iliac artery, called the umbilical artery. ►When blood from the aorta reaches the internal iliac artery, some blood goes into the umbilical arteries and re-enters the placenta, where carbon dioxide and other waste products from the fetus are taken up by the maternal circulation. 164 165 chw.org The Heart in Adulthood and Old Age Age-related changes Hardening and thickening of valve cusps Decline in cardiac reserve Sympathetic control over heart is less efficient Less severe in the physically active Fibrosis of cardiac muscle tissue Lowers the amount of blood the heart can pump 166