Transcript Heart
The Cardiovascular System How your Heart and Blood Vessels Work Learning Points • Overview of the heart and the circulatory system • Coronary artery disease (CAD) and peripheral arterial disease (PAD) • Atrial Fib and Heart Failure • Treatment Options The Heart is a muscle the size of your fist located between the breastbone and the spine just to the left of the midline inside your rib cage A women’s heart is smaller in size than a man’s The Heart • Our bodies need oxygen to survive • Blood carries oxygen to the whole body • The heart pumps the blood (oxygen) through the arteries to the body tissues The Heart • Has four chambers – two upper chambers called Atria – two lower chambers called Ventricles • The left ventricular wall is thicker to be able to pump with more force The Heart • The grade of the left ventricle indicates the amount of damage to the heart muscle: – Grade 1 - normal – Grade 2 - some damage – Grade 3 - more damage – Grade 4 - weakened heart There are four valves: – Tricuspid – Pulmonic – Mitral - Bicuspid – Aortic • valves are strong and flexible • allow blood to flow in one direction • may be injured or diseased requiring repair or replacement Circulation of Blood to the Heart Muscle • Through the Coronary Arteries – right coronary artery – left coronary artery • circumflex • left anterior descending artery Collateral Circulation • Collateral circulation – develops in later age – arteries grow to make a natural bypass towards an area of reduced blood flow Heart’s Electrical Conduction • The Sinoatrial node or pacemaker beats 60-100 times per minute • Atrioventricular node can beat 40-60 times per minute as a backup • Bundle of His and Ventricles can beat 20-40 times per minute as a further backup Artery disease = Atherosclerosis • Process can start before birth • Gradual buildup of plaque in the arteries • Narrows the inside diameter of the arteries • Causes the artery walls to become less elastic Where can blockages occur? • Any artery in the body • Occurs more often in areas where arteries branch • Most common in arteries to the: – head - carotid artery disease – heart - coronary artery disease – legs - peripheral artery disease – organs - eg. kidneys, male sex organs Angina -reduced blood flow to the heart muscle • Temporary lack of oxygen to the heart muscle – is caused by a narrowing in one or more of the coronary arteries • Treated with Nitrospray and rest Angina Symptoms Men and Women: • chest pain • pain into throat and jaw • pain down one or both arms • shortness of breath More common in women: • fatigue • shortness of breath • pain in back between shoulder blades • nausea and vomiting Claudication -reduced blood flow to the muscles in the lower extremities • Temporary lack of oxygen to one or both of your legs – is caused by a narrowing in one or more of the arteries • Treated with rest Reduced blood flow to the brain: signs and symptoms TIA and Stroke • • • • • • • Headache Blurred vision Slurred speech Dizziness Difficulty swallowing Weakness on one side Difficulty with balance How does a Heart Attack occur? • A sudden severe blockage in a coronary artery – caused by plaque rupture and blood clotting • Coronary artery spasm – An involuntary closing of the walls of the artery. Usually occurs for a short period of time but can cause severe blockage • Coronary artery spasm and blood clot occurring together Heart Attack Occurs Other Medical Conditions • Atrial Fibrillation • Heart Failure Atrial Fibrillation • A rapid and irregular heart beat • Most common causes are – Damage to the heart’s structure – Diseases affecting the heart’s valves or pumping system – Long term high blood pressure – Undetermined cause Atrial Fibrillation • Signs and symptoms – Fast, irregular heart beat – Weak, lightheaded, confused – Shortness of breath, chest pain • Treatment – Medication – slow down the heart rate – Pacemaker – to control the heart rate – Surgical – ablation/maze procedure to change the electrical pathway – Blood thinner medication - to prevent blood clots Heart failure • The heart is not strong enough to pump enough blood through the body to meet the demands • Causes – most common – Heart attack – Long term high blood pressure – Heart valve problems Heart failure • Symptoms – – – – – – Shortness of breath Difficulty sleeping laying flat Cough Fluid retention causing swelling Sudden weight gain Fatigue, confusion, impaired memory Heart failure • Treatment goal is to manage the problem – Medications – Exercise – Heart devices eg. Pacemaker, ICD – Surgery - transplant Diagnostic Tests Diagnostic Testing – for the heart • Resting ECG - looking at the heart’s electrical system from 12 different views • Holter Monitor/Loop recorders - longer term ECG monitoring • Exercise stress test - checking ECG changes while increasing the work of the heart • Echocardiogram - heart ultrasound • Stress Thallium - nuclear dye test with or without a stress test • Angiogram - dye test of the heart’s arteries Diagnostic testing – for the legs and head • Doppler studies • Angiograms Treatments Interventions • Angioplasty • Stent Stent – Coronary Artery • A wire mesh tube used to prop open an artery after angioplasty • The stent is placed over the angioplasty balloon catheter • When the balloon is inflated the stent expands Drug Eluting Stent • The stent slowly releases a drug to reduce the chance of a clot forming • Used at doctors’ discretion Angioplasty and stent Surgical Procedures Surgical Procedures • • • • Pacemakers Implantable Defibrillators Endarterectomy Artery Bypass Grafting (coronary, carotid, leg arteries) • Valve Replacement or repair • Heart Transplantation Pacemaker • Stimulates the heart to beat regularly • The generator is the size of a silver dollar and is implanted just beneath the skin. • The leads are threaded into position through veins leading back to the heart. Pacemaker • Battery life is up to 10 years depending on the usage • Has the ability to slow down or speed up the heart rate • In some models, the heart rate can be increased with activity Indications: • heart rate too slow • heart rate too fast Implantable defibrillators (ICD) • A pacemaker with the ability to deliver an electrical shock to correct a life threatening heart rhythm • Indications: • life threatening irregular heart rhythm • heart failure Endarterectomy • Surgical removal of plaque from the inner lining of an artery Coronary Artery Bypass Graft (CABG) • Provides a new supply of blood beyond the site(s) of the blockage • Indications – unstable angina that does not respond to medical treatment – stable angina with severe left-main or significant three-vessel coronary artery disease Leg Artery Bypass • Vein from leg or arm, or synthetic graft is used to bypass a blockage in legs • For severe blockage when there is a risk of losing your limb Valve Replacement and Repair • Valves must flex, stretch, and hold back pressure to function normally • Aortic and Mitral valves are the most commonly repaired or replaced valves • 2 types of valves used – tissue valves from pigs; do not need to take blood thinners – mechanical valves; need to take blood thinners for life Heart Transplantation • People who require heart transplants suffer from severe heart failure • 2 major causes of heart failure are coronary artery disease (CAD) and cardiomyopathy Any Questions?