Cardiovascular System

1. Cardiology is a medical specialty dealing with disorders of the heart. The field includes diagnosis and treatment of cardiovascular system, coronary artery disease, heart failure, congenital heart defects, valvularheart disease and electrophysiology.

2. Cardiovascular System • Cardiovascular system means the system of heart and blood vessels of human body. The term “cardiovascular” is a combination of two word; “Cardio” and “vascular”. The term “cardio” is derived from “cardiac” meaning Heart and the term “vascular” means blood vessels. So the name itself indicates that cardiovascular systems is the system of heart and blood vessels. Cardiovascular system is also known as “Circulatory System”. • Cardiovascular system is made up of three major components; Heart, Blood vessels and blood.

3. The Heart is a muscular organ about the size of a fist, located just behind and slightly left of the breastbone. The heart pumps blood through the network of arteries and veins called the cardiovascular system. The major blood vessels connected to the heart are the aorta, the superior vena cava, the inferior vena cava, the pulmonary artery (which takes oxygen-poor blood from the heart to the lungs where it is oxygenated), the pulmonary vein (which brings oxygen-rich blood from the lungs to the heart), and the coronary arteries (which supply blood to the heart muscle). The Heart has four chambers: The right atrium receives blood from the veins and pumps it to the right ventricle. The right ventricle receives blood from the right atrium and pumps it to the lungs, where it is loaded with oxygen. The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle. The left ventricle (the strongest chamber) pumps oxygen-rich blood to the rest of the body. The left ventricle’s vigorous contractions create our blood pressure. The coronary arteries run along the surface of the heart and provide oxygen-rich blood to the heart muscle. A web of nerve tissue also runs through the heart, conducting the complex signals that govern contraction and relaxation. Heart is made up of three layers; Pericardium, Myocardium and Endocardium.

4. Anatomy and Circulation of the Heart The heart is an amazing organ. It continuously pumps oxygen and nutrient-rich blood throughout the body to sustain life. This fist-sized powerhouse beats (expands and contracts) 100,000 times per day, pumping five or six quarts of blood each minute, or about 2,000 gallons per day. As the heart beats, it pumps blood through a system of blood vessels, called the circulatory system. The vessels are elastic tubes that carry blood to every part of the body. There are three main types of blood vessels: • Arteries. They begin with the aorta, the large artery leaving the heart. Arteries carry oxygen-rich blood away from the heart to all of the body's tissues. They branch several times, becoming smaller and smaller as they carry blood farther from the heart and into organs. • Capillaries. These are small, thin blood vessels that connect the arteries and the veins. Their thin walls allow oxygen, nutrients, carbon dioxide, and other waste products to pass to and from our organ's cells. • Veins. These are blood vessels that take blood back to the heart; this blood lacks oxygen (oxygen-poor) and is rich in waste products that are to be excreted or removed from the body. Veins become larger and larger as they get closer to the heart. The superior vena cava is the large vein that brings blood from the head and arms to the heart, and the inferior vena cava brings blood from the abdomen and legs into the heart. • This vast system of blood vessels -- arteries, veins, and capillaries -- is over 60,000 miles long. That's long enough to go around the world more than twice! • Blood flows continuously through the body's blood vessels. The heart is the pump that makes it all possible.

5. How Does Blood Flow Through the Heart? The right and left sides of the heart work together. The pattern described below is repeated over and over, causing blood to flow continuously to the heart, lungs, and body. Right side • Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium. • As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve. • When the ventricle is full, the tricuspid valve shuts. This prevents blood from flowing backward into the atria while the ventricle contracts. • As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated. Left side • The pulmonary vein empties oxygen-rich blood from the lungs into the left atrium. • As the atrium contracts, blood flows from your left atrium into your left ventricle through the open mitral valve. • When the ventricle is full, the mitral valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts. • As the ventricle contracts, blood leaves the heart through the aortic valve, into the aorta and to the body.

6. Сердечная Недостаточность - определение Сердечная недостаточность - важнейший клинический синдром, характеризующийся неуклонным прогрессированием, что приводит к потере трудоспособности и значительно ухудшает качество жизни всё большего количества больных Сердечная недостаточность стоит на третьем месте среди причин госпитализации и на первом месте у лиц старше 65 лет. В возрастной группе старше 45 лет каждые 10 лет заболеваемость удваивается. В США сердечной недостаточностью страдает около 1% населения (2,5 миллиона человек). Заболеваемость сердечной недостаточностью увеличивается с возрастом. В тех же США ею страдают 10% населения старше 75 лет. В России не менее 4-х млн. больных имеют симптомы ХСН. Ежегодно регистрируется не менее 400 тыс. новых случаев заболевания. В старшей возрастной группе (> 60 лет) ежегодно отмечается удвоение числа больных ХСН. Смертность от сердечной недостаточности составляет около 500 тыс. случаев в год

7. Причины и развитие сердечной недостаточности Сердечная недостаточность — неспособность сердечно-сосудистой системы адекватно обеспечить органы и ткани организма кровью и кислородом в количестве, достаточном для поддержания нормальной жизнедеятельности. В основе сердечной недостаточности лежит нарушение насосной функции одного или обоих желудочков Различие по течению: Хроническая сердечная недостаточность.Данная форма сердечной недостаточности чаще всего является осложнением и следствием какого-то сердечно-сосудистого заболевания. Она является наиболее часто встречающейся и не редко протекает в бессимптомной форме длительное время. Любое заболевание сердца в конечном итоге приводит к снижению его сократительной функции. Обычно, хроническая сердечная недостаточность развивается на фоне инфаркт миокарда, ИБС, кардиомиопатии, артериальной гипертензии или пороков клапанов сердца Острая сердечная недостаточность.Под острой сердечной недостаточностью принято считать внезапно стремительно резко развивающийся процесс - от нескольких дней до нескольких часов. Обычно такое состояние появляется на фоне основного заболевания, при чём не всегда им будет является болезнь сердца или при обострении хронической сердечной недостаточности, а также при отравлении организма кардиотропными ядами (фосфорорганические инсектициды, хинин, сердечные гликозид и так далее).Острая сердечная недостаточность - это наиболее опасная форма синдрома, которая характеризуется резким снижением сократительной функции миокарда или при застое крови в различных органах.

8. Различие по локализации: При правожелудочковой недостаточности идёт застой крови в большом круге кровообращения из-за поражения или/и чрезмерной нагрузке правого отдела сердца. Данный тип синдрома как правило типичен для констриктивного перикардита, пороков трёхстворчатого или митрального клапанов, миокардита различной этиологии, тяжёлой формы ИБС, застойной кардиомиопатии, а также как осложнение левожелудочковой недостаточности. Правожелудочковая сердечная недостаточность проявляется следующими симптомами:- Набухание шейных вен - акроцианоз (синюшность пальцев, подбородка, ушей, кончика носа)- повышение венозного давления - отёчность различной степени, начиная от вечерних отёков ног и до асцита, гидроторакса и гидроперикардита - увеличение печени, иногда с болям в правом подреберье

9. Левожелудочковая сердечная недостаточность характеризуется застоем крови в малом круге кровообращения, что приводит к нарушению мозгового и/или коронарного кровообращения. Возникает при перегрузке и/или поражении правого сердечного отдела. Данная форма синдрома обычно является осложнением при инфарктах миокарда, гипертонической болезни, миокардите, аортальных пороках сердца, аневризме левого желудочка и прочих поражениях левого отела сердечно-сосудистой системы. Характерные симптомы левожелудочковой сердечной недостаточности:- при нарушении мозгового кровообращения характерны головокружение, обмороки, потемнение в глазах;- при нарушении коронарного кровообращения развивается стенокардия со всеми её симптомами;- тяжёлая форма левожелудочковой сердечной недостаточности проявляется отёком лёгких или сердечной астмой;- в некоторых случаях могут сочетаться нарушения коронарного и мозгового кровообращения и соответственно симптомы тоже.

10. Дистрофическая форма сердечной недостаточности.Это конечная стадия недостаточности правого желудочка сердца. Проявляется появлением кахексии, то есть истощением всего организма и дистрофическими изменениями кожных покровов, которые проявляются в неестественном блеске кожи, истончении, сглаженности рисунка и излишней дряблости. В тяжёлых случаях процесс доходить до анасарки, то есть тотального отёка полостей тела и кожи. Происходит нарушение в организме водно-солевого баланса. Анализ крови показывает снижение уровня альбуминов.В некоторых случаях встречается одновременно лево-и право-желудочковая недостаточность. Обычно это встречается при миокардите, когда правожелудочковая недостаточность становится осложнением нелечённой левожелудочковой. Или же при отравлении кардиотропными ядами.

11. По стадиям развития, сердечная недостаточность разделяется по классификации В.Х. Василенко и Н.Д. Стражеско на следующие группы: Доклиническая стадия. На этом этапе больные не ощущают каких-то особых изменений в их состоянии и выявляется исключительно при тестировании определёнными аппаратами в состоянии нагрузки.I начальная стадия проявляется тахикардией, одышкой и быстрой утомляемостью но всё это только при определённой нагрузке.II стадии характеризуется застойными явлениями в тканях и органах, которые сопровождаются развитием в них обратимых нарушений функций. Здесь различают подстадии:IIА стадия - не резко выраженные признаки застоя, возникающие только в большом или только в малом круге кровообращения.IIБ стедия- резко выраженный отёк в двух кругах кровообращения и явными гемодинамические нарушения.III стадия - К симптомам IIБ сердечной недостаточности присоединяются признаки морфологических необратимых изменений в различных органах по причине длительной гипоксии и белковой дистрофии, а также развития склероза в их тканях (цирроз печени, гемосидероз легких и так далее).

12. Также существует классификация Нью-Йоркской Ассоциации Кардиологии(NYHA), которая разделяет степени развития сердечной недостаточности исходя отталкиваясь исключительно от принципа функциональной оценки тяжести состояния пациента. При этом, не уточняются гемодинамические и морфологические изменения в обоих кругах кровообращения. В практической кардиологии эта классификация наиболее удобная.I ФК - Нет ограничения физической активности человека, одышка проявляется при подъёме выше третьего этажа.II ФК - незначительное ограничение активности, сердцебиение, одышка, утомляемость и прочие проявления возникают исключительно при физической нагрузке обычного типа и более.III ФК - Симптомы проявляются при самой незначительной физической нагрузке, что приводит к значительному снижению активности. В покое клинических проявлений не наблюдается.IV ФК - Симптомы СН проявляются даже в состоянии пока и увеличиваются при самых незначительных физических нагрузках.

13. Терминология: Периферические отеки Застойные явления по Рентгенографии грудной клетки …..

14. The heart's electrical system The heart is, in the simplest terms, a pump made up of muscle tissue. The heart's pumping action is regulated by an electrical conduction system that coordinates the contraction of the various chambers of the heart.

15. How Does the Heart Beat? • The atria and ventricles work together, alternately contracting and relaxing to make the heart beat and pump blood. The electrical system of the heart is the power source that makes this possible. • Heartbeat is triggered by electrical impulses that travel down a special pathway through the heart. • The impulse starts in a small bundle of specialized cells called the SA node (sinoatrial node), located in the right atrium. This node is known as the heart's natural pacemaker. The electrical activity spreads through the walls of the atria and causes them to contract. • A cluster of cells in the center of the heart between the atria and ventricles, the AV node (atrioventricular node) is like a gate that slows the electrical signal before it enters the ventricles. This delay gives the atria time to contract before the ventricles do. • The His-Purkinje network is a pathway of fibers that sends the impulse to the muscular walls of the ventricles, causing them to contract. • At rest, a normal heart beats around 50 to 99 times a minute. Exercise, emotions, fever, and some medications can cause your heart to beat faster, sometimes to well over 100 beats per minute.

16. What Are the Coronary Arteries? The heart receives its own supply of blood from a network of arteries, called the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet: • Right coronary artery supplies the right atrium and right ventricle with blood. It usually branches into the posterior descending artery, which supplies the bottom portion of the left ventricle and back of the septum with blood. • Left main coronary artery branches into the circumflex artery and the left anterior descending artery. The circumflex artery supplies blood to the left atrium, side, and back of the left ventricle, and the left anterior descending artery supplies the front and bottom of the left ventricle and the front of the septum with blood. These arteries and their branches supply all parts of the heart muscle with blood. When the coronary arteries narrow to the point that blood flow to the heart muscle is limited (coronary artery disease), a network of tiny blood vessels in the heart that aren't usually open called collateral vessels may enlarge and become active. This allows blood to flow around the blocked artery to the heart muscle, protecting the heart tissue from injury.

17. What Is Heart Disease? Bring up heart disease, and most people think of a heart attack. But there are many conditions that can undermine the heart's ability to do its job. These include coronary artery disease, cardiomyopathy, Heart Valve Disease, arrhythmia, heart failure, Hypertension...

18. Heart Conditions • Coronary artery disease: Over the years, cholesterol plaques can narrow the arteries supplying blood to the heart. The narrowed arteries are at higher risk for complete blockage from a sudden blood clot (this blockage is called a heart attack). • Stable angina pectoris: Narrowed coronary arteries cause predictable chest pain or discomfort with exertion. The blockages prevent the heart from receiving the extra oxygen needed for strenuous activity. Symptoms typically get better with rest. • Unstable angina pectoris: Chest pain or discomfort that is new, worsening, or occurs at rest. This is an emergency situation as it can precede a heart attack, serious abnormal heart rhythm, or cardiac arrest. • Myocardial infarction (heart attack): A coronary artery is suddenly blocked. Starved of oxygen, part of the heart muscle dies. • Arrhythmia (dysrhythmia): An abnormal heart rhythm due to changes in the conduction of electrical impulses through the heart. Some arrhythmias are benign, but others are life-threatening. • Congestive heart failure: The heart is either too weak or too stiff to effectively pump blood through the body. Shortness of breath and leg swelling are common symptoms. • Cardiomyopathy: A disease of heart muscle in which the heart is abnormally enlarged, thickened, and/or stiffened. As a result, the heart's ability to pump blood is weakened. • Myocarditis: Inflammation of the heart muscle, most often due to a viral infection. • Pericarditis: Inflammation of the lining of the heart (pericardium). Viral infections, kidney failure, and autoimmune conditions are common causes.

19. Heart Conditions • Pericardial effusion: Fluid between the lining of the heart (pericardium) and the heart itself. Often, this is due to pericarditis. • Atrial fibrillation: Abnormal electrical impulses in the atria cause an irregular heartbeat. Atrial fibrillation is one of the most common arrhythmias. • Pulmonary embolism: Typically a blood clot travels through the heart to the lungs. • Heart valve disease: There are four heart valves, and each can develop problems. If severe, valve disease can cause congestive heart failure. • Heart murmur: An abnormal sound heard when listening to the heart with a stethoscope. Some heart murmurs are benign; others suggest heart disease. • Endocarditis: Inflammation of the inner lining or heart valves of the heart. Usually, endocarditis is due to a serious infection of the heart valves. • Mitral valve prolapse: The mitral valve is forced backward slightly after blood has passed through the valve. • Sudden cardiac death: Death caused by a sudden loss of heart function (cardiac arrest). • Cardiac arrest: Sudden loss of heart function.

20. Heart Tests • Electrocardiogram (ECG or EKG): A tracing of the heart’s electrical activity. Electrocardiograms can help diagnose many heart conditions. • Echocardiogram: An ultrasound of the heart. An echocardiogram provides direct viewing of any problems with the heart muscle’s pumping ability and heart valves. • Cardiac stress test: By using a treadmill or medicines, the heart is stimulated to pump to near-maximum capacity. This may identify people with coronary artery disease. • Cardiac catheterization: A catheter is inserted into the femoral artery in the groin and threaded into the coronary arteries. A doctor can then view X-ray images of the coronary arteries or any blockages and perform stenting or other procedures. • Holter monitor: If a doctor suspects an arrhythmia, a portable heart monitor can be worn. Called a Holter monitor, it records the heart's rhythm continuously for a 24 hour period. • Event monitor: If a doctor suspects an infrequent arrhythmia, a portable heart monitor called an event monitor can be worn. When you develop symptoms, you can push a button to record the heart's electrical rhythm.

21. Heart Treatments • Exercise: Regular exercise is important for heart health and most heart conditions. Talk to your doctor before starting an exercise program if you have heart problems. • Angioplasty: During cardiac catheterization, a doctor inflates a balloon inside a narrowed or blocked coronary artery to widen the artery. A stent is often then placed to keep the artery open. • Percutaneous coronary intervention (PCI): Angioplasty is sometimes called a PCI or PTCA (percutaneous transluminal coronary angioplasty) by doctors. • Coronary artery stenting: During cardiac catheterization, a doctor expands a wire metal stent inside a narrowed or blocked coronary artery to open up the area. This lets blood flow better and can abort a heart attack or relieve angina (chest pain). • Thrombolysis: “Clot-busting” drugs injected into the veins can dissolve a blood clot causing a heart attack. Thrombolysis is generally only done if stenting is not possible. • Lipid-lowering agents: Statins and other cholesterol (lipid) lowering drugs reduce the risk for heart attack in high-risk people. • Diuretics: Commonly called water pills, diuretics increase urination and fluid loss. This reduces blood volume, improving symptoms of heart failure. • Beta-blockers: These medicines reduce strain on the heart and lower heart rate. Beta-blockers are prescribed for many heart conditions, including heart failure and arrhythmias. • Angiotensin-converting enzyme inhibitors (ACE inhibitors): These blood pressure medicines also help the heart after some heart attacks or in congestive heart failure. • Aspirin: This powerful medicine helps prevent blood clots (the cause of heart attacks). Most people who have had heart attacks should take aspirin. • Clopidogrel (Plavix): A clot-preventing medicine that prevents platelets from sticking together to form clots. Clopidogrel is especially important for many people who have had stents placed. • Antiarrhythmic medications: Numerous medicines help control the heart’s rate and electrical rhythm. These help prevent or control arrhythmias. • AED (automated external defibrillator): If someone has sudden cardiac arrest, an AED can be used to assess the heart rhythm and send an electrical shock to the heart if necessary. • ICD (Implantable cardioverter defibrillator): If a doctor suspects you are at risk for a life-threatening arrhythmia, an implantable cardioverter defibrillator may be surgically implanted to monitor your heart rhythm and send an electrical shock to the heart if necessary. • Pacemaker: To maintain a stable heart rate, a pacemaker can be implanted. A pacemaker sends electrical signals to the heart when necessary to help it beat properly.

22. Medications • ACE Inhibitors • Angiotensin converting enzyme (ACE) inhibitors are heart medications that widen or dilate your blood vessels to improve the amount of blood your heart pumps and lower blood pressure. • Angiotension II Receptor Blockers • These heart drugs decrease certain chemicals that narrow the blood vessels, allowing blood to flow more easily through your body. They also decrease certain chemicals that cause salt and fluid build-up in the body. • Antiarrhythmics • Antiarrhythmia drugs are used to treat abnormal heart rhythms resulting from irregular electrical activity of the heart. • Antiplatelet Drugs • Antiplatelet drugs are used to treat heart disease. They are a group of powerful medications that prevent the formation of blood clots. • Aspirin Therapy • For more than 100 years, aspirin has been used as a pain reliever. Since the 1970s, aspirin has also been used to prevent and manage heart disease and stroke. • Beta-Blocker Therapy • Beta-blockers are one of the most widely prescribed class of drugs to treat hypertension (high blood pressure) and are a mainstay treatment of congestive heart failure. • Calcium Channel Blocker Drugs • Calcium channel blockers are heart disease drugs that relax blood vessels and increase the supply of blood and oxygen to the heart while also reducing the heart's workload. • Clot Buster Drugs • Clot buster drugs, or thrombolytic therapy, are a type of heart medication given in the hospital through the veins (intravenous) to break up blood clots. • Digoxin • If you have heart disease, Digoxin is a medication that helps an injured or weakened heart work more efficiently to send blood through the body. • Diuretics • iuretics, commonly known as "water pills," help your body get rid of unneeded water and salt through the urine. Getting rid of excess fluid makes it easier for your heart to pump and controls blood pressure. • Nitrates • Nitrates are vasodilators that are used to treat angina in people with coronary artery disease or chest pain caused by blocked blood vessels of the heart. • Warfarin and Other Blood Thinners • Warfarin, which goes by the brand name Coumadin, is an anticoagulant medication. This means that it helps prevent clots from forming in the blood. Blood thinners are used to treat some types of heart disease.

23. What Is a Heart Attack? • Every year, million of peoples have a heart attack -- a sudden interruption in the heart's blood supply. This happens when there is a blockage in the coronary arteries, the vessels that carry blood to the heart muscle. When blood flow is blocked, heart muscle can be damaged very quickly and die. Prompt emergency treatments have reduced the number of deaths from heart attacks in recent years

24. Heart Attack Symptoms • A heart attack is an emergency even when symptoms are mild. Warning signs include: • Pain or pressure in the chest • Discomfort spreading to the back, jaw, throat, or arm • Nausea, indigestion, or heartburn • Weakness, anxiety, or shortness of breath • Rapid or irregular heartbeats

25. Signs of Coronary Artery Disease A precursor to a heart attack, coronary artery disease or CAD occurs when sticky plaque builds up inside the coronary arteries. This narrows the arteries, making it more difficult for blood to flow through. Many people don't know they have CAD until a heart attack strikes. But there are warning signs, such as recurring chest pain caused by the restricted blood flow. This pain is known as angina.

26. Inside a Heart Attack • The plaque deposited in your arteries is hard on the outside and soft and mushy on the inside. Sometimes the hard outer shell cracks. When this happens, a blood clot forms around the plaque. If the clot completely blocks the artery, it cuts off the blood supply to a portion of the heart. Without immediate treatment, that part of the heart muscle could be damaged or destroyed

27. Sudden Cardiac Death • Sudden cardiac death (SCD) accounts for half of all heart disease deaths in the U.S., but it's not the same as a heart attack. SCD occurs when the heart's electrical system goes haywire, causing it to beat irregularly and dangerously fast. The heart's pumping chambers may quiver instead of pumping blood out to the body. Without CPR and restoration of a regular heart rhythm, death can occur in minutes.

28. Arrhythmia: Erratic Heart Beat • Regular electrical impulses cause your heart to beat. But sometimes those impulses become erratic. The heart may race, slow down, or quiver. Arrhythmias are often harmless variations in rhythm that pass quickly. But some types make your heart less effective at pumping blood, and that can take a serious toll on the body. Let your doctor know if you've noticed your heart beating abnormally.

29. Cardiomyopathy • Cardiomyopathy is a disease involving changes in the heart muscle. These changes may interfere with the heart's ability to pump effectively, which can lead to a chronic condition called heart failure. Cardiomyopathy is sometimes associated with other chronic conditions, such as high blood pressure or heart valve disease.

30. Heart Failure • Heart failure doesn't mean your heart stops working. It means the heart can't pump enough blood to meet the body's needs. Over time, the heart gets bigger to hold more blood, it pumps faster to increase the amount of blood moving out of it, and the blood vessels narrow. The heart muscle may also weaken, reducing the blood supply even more. Most cases of heart failure are the result of coronary artery disease and heart attacks.

31. Congenital Heart Defect • A congenital heart defect is one that's present at birth. The problem could be a leaky heart valve, malformations in the walls that separate the heart chambers, or other heart problems. Some defects are not found until a person becomes an adult. Some need no treatment. Others require medicine or surgery. People with congenital heart defects may have a higher risk of developing complications such as arrhythmias, heart failure, and heart valve infection, but there are ways to reduce this risk.

32. Testing: Electrocardiogram (EKG) • An EKG (also ECG) is a painless test that uses electrodes placed on the skin to record the heart's electrical activity. The test provides information about your heart rhythm and damage to the heart muscle. An EKG can help your doctor diagnose a heart attack and evaluate abnormalities such as an enlarged heart. The results can be compared to future EKGs to track changes in the condition of your heart.

33. Testing: Stress Test • The stress test measures how your heart responds to exertion. If you have an exercise stress test, you'll either walk on a treadmill or ride a stationary bike while the level of difficulty increases. At the same time, your EKG, heart rate, and blood pressure will be monitored as your heart works harder. Doctors use a stress test to evaluate whether there is an adequate supply of blood to the heart muscle.

34. Testing: Holter Monitor • A Holter monitor is a portable heart rhythm recorder. If your doctor suspects a heart rhythm problem, she may ask you to wear one for one or two days. It records the heart's continuous electrical activity day and night, compared with an EKG, which is a snapshot in time. The doctor will probably also ask you to keep a log of your activities and to note any symptoms and when they occur.

35. Testing: Chest X-ray • A chest X-ray is a picture of your heart, lungs, and chest bones that's made by using a very small amount radiation. Chest X-rays can be used to look for heart and lung abnormalities. • In this image, the bulge seen on the right side is an enlarged left ventricle, the heart's main pumping chamber.

36. Testing: Echocardiogram • An echocardiogram uses sound waves (ultrasound) to generate moving images of the heart. The test can assess the chambers and valves of your heart and how well your heart muscle and heart valves are working. It's useful in diagnosing and evaluating several types of heart disease, as well as evaluating the effectiveness of treatments.

37. Testing: Cardiac CT • Cardiac computerized tomography (known as cardiac CT) takes detailed images of the heart and its blood vessels. A computer stacks the images to create a 3-D picture of heart. A cardiac CT can be used to look for plaque or calcium buildup in the coronary arteries, heart valve problems, and other types of heart disease.

38. Testing: Cardiac Catheterization • Cardiac catheterization helps diagnose and treat some heart conditions. The doctor guides a narrow tube, called a catheter, through a blood vessel in your arm or leg until it reaches the coronary arteries. Dye is injected into each coronary artery, making them easy to see with an X-ray. This reveals the extent and severity of any blockages. Treatments such as angioplasty or stenting can be done during this procedure.

39. Treatment: Angioplasty • Angioplasty is used to open a blocked heart artery and improve blood flow to the heart. The doctor inserts a thin catheter with a balloon on the end into the artery. When the balloon reaches the blockage, it is expanded, opening up the artery and improving blood flow. The doctor may also insert a small mesh tube, called a stent, to help keep the artery open after angioplasty.

40. Treatment: Bypass Surgery • Bypass surgery is another way to improve the heart's blood flow. It gives blood a new pathway when the coronary arteries have become too narrow or blocked. During the surgery, a blood vessel is first moved from one area of the body -- such as the chest, legs, or arms -- and attached to the blocked artery, allowing it to bypass the blocked part.

41. Heart Attack andUnstable Angina • Symptoms of a heart attack include: • Chest pain or pressure, or a strange feeling in the chest. • Sweating. • Shortness of breath. • Nausea or vomiting. • Pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly, or in one or both shoulders or arms. • Lightheadedness or sudden weakness. • A fast or irregular heartbeat. Unfortunately, angina has a variety of signs and symptoms, and there may not even be specific chest pain. Other locations of pain and other symptoms may include shoulder or back ache,upper abdominal pain,nausea, and indigestion. Women, the elderly, and people with diabetes may have different perceptions of pain or have no discomfort at all. Instead, they may complain of malaise or fatigue and generalized weakness and the inability to complete routine physical tasks such as walking or climbing stairs.

42. People who have unstable angina often describe their symptoms as: • Starting within the past 2 months and becoming more severe. • Limiting their physical activity. • Suddenly becoming more frequent, severe, or longer-lasting or being brought on by less exertion than before. • Occurring at rest with no obvious exertion or stress. Some say these symptoms may wake you up. • Not responding to rest or nitroglycerin. The symptoms of stable angina are different from those of unstable angina. Stable angina occurs at predictable times with a specific amount of exertion or activity and may continue without much change for years. It is relieved by rest or nitrates (nitroglycerin) and usually lasts less than 5 minutes.

43. The heart requires its own constant supply of oxygen and nutrients, like any muscle in the body. Two large, branching coronary arteries deliver oxygenated blood to the heart muscle. If one of these arteries or branches becomes blocked suddenly, a portion of the heart is starved of oxygen, a condition called "cardiac ischemia.“ • The coronary arteries are at risk for narrowing as cholesterol deposits, called plaques, build up inside the artery. If the arteries narrow enough, blood supply to the heart muscle may be compromised (slowed down), and this slowing of blood flow to the heart causes pain, or angina. • A heart attack or myocardial infarction occurs when a plaque ruptures, allowing a blood clot to form. This completely obstructs the artery, stopping all blood flow to part of the heart muscle, and that portion of muscle dies. • If cardiac ischemia lasts too long, the starved heart tissue dies. This is a heart attack, otherwise known as a myocardial infarction -- literally, "death of heart muscle."

44. Medicine to lower blood pressure and the heart's workload: • Angiotensin-converting enzyme (ACE) inhibitors • Beta-blockers • Medicine to prevent blood clots from forming and causing another heart attack: • Aspirin • Antiplatelet medicines • Medicine to lower cholesterol: • Statins • Medicine to manage angina symptoms: • Nitroglycerin

45. Angioplasty. Doctors try to do angioplasty as soon as possible after a heart attack. Angioplasty might be done for unstable angina, especially if there is a high risk of a heart attack. • Angioplasty gets blood flowing to the heart. It opens a coronary artery that was narrowed or blocked during the heart attack. • Bypass surgery. If angioplasty is not right for you, emergency coronary artery bypass surgery may be done. For example, bypass surgery might be a better option because of the location of the blockage or because of numerous blockages.

46. Arrhythmia An arrhythmia is an irregular heart rhythm. An arrhythmia can occur with a normal heart rate or with fast or slow heart rates. Causes may include coronary artery disease, heart attack, heart surgery, blood imbalances, and more. There are many types of arrhythmias including atrial fibrillation and atrial flutter. Treatments include medications and lifestyle changes, cardioversion, pacemakers, ICDs, and surgery. Follow the links below to find WebMD's comprehensive coverage about how arrhythmia is caused, what it looks like, how to treat it, and much more. An arrhythmia can be silent and not cause any symptoms. A doctor can detect an irregular heartbeat during a physical exam by taking your pulse or through an electrocardiogram (ECG or EKG). When symptoms of an arrhythmia occur, they may include: • Palpitations (a feeling of skipped heart beats, fluttering or "flip-flops"). • Pounding in your chest. • Dizziness or feeling light-headed. • Fainting. • Shortness of breath. • Chest discomfort. • Weakness or fatigue (feeling very tired).

47. The heart's electrical system The heart is, in the simplest terms, a pump made up of muscle tissue. The heart's pumping action is regulated by an electrical conduction system that coordinates the contraction of the various chambers of the heart.

48. An electrical stimulus is generated by the sinus node (also called the sinoatrial node, or SA node), which is a small mass of specialized tissue located in the right atrium (right upper chamber of the heart). The sinus node generates an electrical stimulus regularly (60 to190 times per minute, depending on the age of the child and his or her activity level). This electrical stimulus travels down through the conduction pathways (similar to the way electricity flows through power lines from the power plant to your house) and causes the heart's lower chambers to contract and pump out blood. The right and left atria (the two upper chambers of the heart) are stimulated first and contract a short period of time before the right and left ventricles (the two lower chambers of the heart). The electrical impulse travels from the sinus node to the atrioventricular node (also called AV node), where impulses are slowed down for a very short period, then continue down the conduction pathway via the bundle of His into the ventricles. The bundle of His divides into right and left pathways to provide electrical stimulation to the right and left ventricles. Normally, at rest, as the electrical impulse moves through the heart, the heart contracts about 60 to 140 times a minute, depending on a child's age. Each contraction of the ventricles represents one heartbeat. The atria contract a fraction of a second before the ventricles so their blood empties into the ventricles before the ventricles contract.

49. An arrhythmia (abnormal heartbeat) may occur when: • The heart's natural pacemaker (the sinus node) develops an abnormal rate or rhythm. • The normal conduction pathway is interrupted. • Another part of the heart takes over as pacemaker.

50. The types of arrhythmias The types of arrhythmias include: • Premature atrial contractions. These are early extra beats that originate in the atria (upper chambers of the heart). They are harmless and generally do not require treatment. • Premature ventricular contractions (PVCs). These are among the most common arrhythmias and occur in people with or without heart disease. This is the skipped heartbeat we all occasionally experience. In some people, it can be related to stress, too much caffeine or nicotine, or too much exercise. But sometimes, PVCs can be caused by heart disease or electrolyte imbalance. People who have a lot of PVCs, and/or symptoms associated with them, should be evaluated by a heart doctor. However, in most people, PVCs are usually harmless and rarely need treatment. • Atrial fibrillation. Atrial fibrillation is a very common irregular heart rhythm that causes the atria, the upper chambers of the heart, to contract abnormally. • Atrial flutter. This is an arrhythmia caused by one or more rapid circuits in the atrium. Atrial flutter is usually more organized and regular than atrial fibrillation. This arrhythmia occurs most often in people with heart disease and in the first week after heart surgery. It often converts to atrial fibrillation. • Paroxysmal supraventricular tachycardia (PSVT). A rapid heart rate, usually with a regular rhythm, originating from above the ventricles. PSVT begins and ends suddenly. There are two main types: accessory path tachycardias and AV nodal reentrant tachycardias (see below). • Accessory pathway tachycardias. A rapid heart rate due to an extra abnormal pathway or connection between the atria and the ventricles. The impulses travel through the extra pathways as well as through the usual route. This allows the impulses to travel around the heart very quickly, causing the heart to beat unusually fast.