CNM Biomedicine: Human Sciences Cardiovascular System II (Part Two) PDF

Biomedicine: Human Sciences Lecture 6: Cardiovascular System Part Two 1 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Learning Outcomes In today’s topic you will learn: About the...

Biomedicine: Human Sciences Lecture 6: Cardiovascular System Part Two 1 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Learning Outcomes In today’s topic you will learn: About the circulatory system, including the structure and function of the blood vessels and heart. About blood pressure, blood cholesterol and pulse rate. The signs, symptoms, investigation procedures and some orthodox treatments of common heart and blood vessel pathologies. 2 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Circulation There are two types of circulation in the body: Systemic circulation: Blood from the heart is distributed around the body before returning to the heart. Pulmonary circulation: Blood from the heart to the lungs and back to the heart. systemic = relating to body systems / entire body pulmonary = meaning lungs. 3 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Blood Vessels Blood vessels transport blood around the body. The three main types of blood vessels are arteries, veins and capillaries. Smaller arteries are called ‘arterioles, whilst smaller veins are called ‘venules.’ Capillaries are small blood vessels connecting arterioles and venules. Capillaries specialise in the exchange of substances between blood and cells / tissues. 4 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Blood Vessels Arteries and arterioles: Veins and venules: Location: Carries blood away from Carries blood towards the heart. the heart. Blood Oxygenated Deoxygenated content: (exceptions: Pulmonary (exceptions: Pulmonary and umbilical arteries). and umbilical veins). Pressure: High. Low. Valves: No Yes Towards Away heart from heart 5 © CNM: Human Sciences ― Cardiovascular System II. BQ.  tunic = coat Blood Vessel Structure externa = outer media = middle intima = innermost Most blood vessels contain three layers: 1. Tunica intima: The innermost layer made of endothelium (epithelial tissue) that protects the vessel wall and functions to secrete chemicals. This layer is in direct contact with blood and is well positioned to monitor and respond to changes. 2. Tunica media: Layer of smooth muscle that controls blood vessel diameter. 3. Tunica externa: Outermost layer made of elastic and collagen fibres. © CNM: Human Sciences ― Cardiovascular System II. BQ. 6  Blood Vessel Structure The thickness (and presence) of each layer depends on the type of blood vessel: Arteries and arterioles have a thicker tunica media and are hence more muscular. Veins and venules generally have thin walls. The tunica externa is their thickest layer. Capillaries contain only an endothelium. 7 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Blood Vessel Structure Arteries: Arterioles: Veins: Large portions of elastic Arterioles are small Skeletal muscle tissue (high pressure). arteries and are vital in contraction aids maintaining blood return of venous Sympathetic nerve pressure. blood to the heart. fibres innervate smooth muscle and cause The pumping action Normal vasoconstriction. of heart is major drive. The respiratory If reduced sympathetic Vasoconstriction pump also aids activity, nitric oxide is return (diaphragm). released which causes Vasodilation Valves prevent vasodilation. backflow of blood. 8 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Veins Valves Incompetent valves 9 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Capillaries Capillaries contain only one layer of cells (the ‘endothelium’). Capillaries have no tunica externa or Capillaries function in the exchange of tunica media. substances between blood and cells. Found near every cell in the body. Tissues with high metabolic demand have extensive capillary network. The structure of capillaries allows easier passing of substances between the blood and cells / tissue (H2O, O2, CO2 and other nutrients / wastes). 10 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Capillary Exchange The key function of the cardiovascular system is to keep blood flowing through capillaries to allow exchange. Water — by osmosis Nutrients — by facilitated diffusion and active transport. Gases — carbon dioxide and oxygen by diffusion. 11 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Where is Your Blood? 64% blood in systemic veins / venules. 13% in systemic arteries / arterioles. 9% in pulmonary vessels. 7% in capillaries. 7% in heart. 12 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Portal Circulation hepatic = liver Venous blood passes from the digestive tract, spleen and pancreas directly to the liver. This system of blood flow is known as the hepatic first pass. The vessel that carries the absorbed substances is called the portal vein. 13 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Vasodilation and Vasoconstriction All blood vessels (except capillaries) contain smooth muscle which are influenced by the autonomic nervous system: Sympathetic nervous system stimulation causes vasoconstriction. The parasympathetic nervous system has little influence. Vasodilation reduces blood pressure. Vasoconstriction increases blood pressure. 14 © CNM: Human Sciences ― Cardiovascular System II. BQ.  The Heart The heart is a fist-sized muscular organ that functions to pump blood around the body. The heart contracts to pump blood through blood vessels. Blood pumps through 60,000 miles of blood vessels within the human body. The heart is about 12 cm long, 9 cm wide. Average mass: 250 g in females. 300 g in males. 15 © CNM: Human Sciences ― Cardiovascular System II. BQ.  inter = between The Heart costal = ribs LOCATION: The heart rests on the diaphragm, in the thoracic near the midline, pointing left. The heart is covered anteriorly by the sternum and ribs 3–6. Apex of the heart is formed by the left ventricle and lies in the fifth intercostal space. 16 © CNM: Human Sciences ― Cardiovascular System II. BQ.  peri- = around Heart Layers myo- = muscle endo- = inside or within Endocardium: Myocardium: Pericardium: Innermost layer. Middle layer. Outer layer of the heart. Thin layer of Consists of Thin double-layered endothelium cardiac membrane: Contains a overlying a thin layer muscle and fibrous pericardium that of connective tissue. makes up attaches to the diaphragm and 95% of heart. an inner serous pericardium. Provides a smooth Functions to Functions to keep the heart lining for the heart pump blood in position within the thorax chambers (also out of the and allow free movement covers heart valves). heart. during contractions. © CNM: Human Sciences ― Cardiovascular System II. BQ. 17  The Myocardium The thickest layer of the heart wall is the myocardium — making up 95% of the heart. The myocardium is formed of cardiac muscle. Cardiac muscle is striated and involuntary. A unique property of cardiac muscle is its ability to generate its own rhythm of contraction (cardiac muscle is autorhythmic). As the myocardium is so metabolically active, the arterial supply is vital. The coronary artery delivers oxygenated blood to the myocardium. 18 © CNM: Human Sciences ― Cardiovascular System II. BQ.  The Heart The left and right coronary arteries Aorta are the first branches of the aorta. Left coronary artery They supply the myocardium with an abundance of oxygenated Right coronary blood. artery 19 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Myocardial Metabolism Despite the heart accounting for only 1% of the total body weight, the myocardium consumes 10% of the total body oxygen consumption. Cardiac muscle is an aerobic organ with a limited capacity to work under oxygen debt. Therefore, poor oxygen delivery to the myocardium could cause cell death (necrosis). Fatty acids are the predominant fuel in cardiac muscle (50–70%), followed by glucose (30%). During exercise, the heart can use lactic acid to produce ATP. 20 © CNM: Human Sciences ― Cardiovascular System II. BQ.  The Heart Chambers The heart is divided into four chambers: REMEMBER: 1. Right atrium. Atria = Arrivals 2. Right ventricle. 3. Left atrium. 4. Left ventricle. The atria are the receiving chambers of the heart (receive venous blood). The atria pump blood into the ventricles. The atria are separated by the interatrial septum, whilst the ventricles are separated by the interventricular septum. 21 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Heart: Blood Flow tri- = three 1. Deoxygenated blood from the superior and inferior vena cava arrive in the right atrium (3 mm thick). It pumps blood through the tricuspid valve into the right ventricle (5 mm thick). 3 2. The right ventricle contracts and pumps the deoxygenated blood through the pulmonary valve and 1 2 into the pulmonary trunk which divides into left and right pulmonary arteries. 3. The blood flows through the lungs where gas exchange occurs. 22 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Heart: Blood Flow bi- two 4. Blood (now oxygenated) returns to the left atrium (3 mm thick) via the pulmonary vein. 5. The left atrium pumps the oxygenated blood through the mitral / bicuspid valve. into the left ventricle (10‒15 mm thick). 6 4 6. The left ventricle contracts and pumps oxygenated blood through 5 the aortic valve into the ascending aorta. Some of the blood in the aorta flows into the coronary arteries which carry blood to the heart wall. 23 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Foramen Ovale and Ductus Arteriosum Foramen ovale: ductus = duct (tube) Within the interatrial septum is a arteriosum = artery depression called the fossa ovalis. foramen = hole fossa = shallow depression Previously called the foramen ovale in foetal development, where it would shunt blood from the right atrium to left atrium, to bypass the lungs. Ductus arteriosum: During foetal life (8 weeks+), a temporary blood vessel called the ductus arteriosus shunts blood from the pulmonary trunk to the aorta. Closes after birth to form ligamentum arteriosum. 24 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Summary Quiz: 1. What is meant by hepatic first pass? 2. Name the THREE layers of a blood vessel wall. 3. How do veins prevent the backflow of blood? 4. What type of blood vessel plays a key role in regulating blood pressure? 5. Name the FOUR heart chambers in order of blood flow. 6. What vessel between the heart and lungs carries deoxygenated blood? 7. Name the THREE layers of the heart wall. 8. Where is the pulmonary valve located? 9. Is the right or left ventricle thicker? Why is one side thicker? 10. Does the left atrium contain oxygenated or deoxygenated blood? 25 © CNM: Human Sciences ― Cardiovascular System II. BQ. Exercise: Label the Image 26 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Heart Contraction auto = Greek for self The myocardium performs periodic contractions through a network of cardiac fibres that are self-excitable (autorhythmic). The myocardium repeatedly generates nerve impulses. Hormones, age, sex, body position, exercise, stress and temperature all influence heart rate and strength. Sympathetic Nervous Parasympathetic Nervous System: System: Increases rate Decreases rate and and strength strength of contraction of contraction. (via Vagus nerve). Vasoconstriction. Little influence on blood vessels. 27 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Conduction System of the Heart 1. Sinoatrial node (SA node): The SA node is the pacemaker of the heart — sets rate and rhythm. Initiates cardiac conduction, located in the right atrial wall. 1 Each nerve impulse from the SA node 2 propagates through each atrium via gap junctions, causing atrial contraction. 2. Atrioventricular node (AV node): A relay station — conducts impulses at a slightly slower rate to allow the atria to finish contracting. Located in the bottom right of the interatrial septum. 28 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Conduction System of the Heart 3. Atrioventricular bundle (Bundle of His): Only site where nerve impulses can conduct from atria to ventricles. 4. Right and left bundle branches: From the bundle of His, the nerve impulse enters the left and right bundle branches, which extend the interventricular septum towards the apex of the heart. 5. Purkinje fibres: 5 Finally, the Purkinje fibres rapidly conduct the 3 4 nerve impulse beginning at the apex of the heart, up the remainder of the ventricular myocardium causing ventricular contraction. 29 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Pulse Rate The pulse is a blood pressure wave originating from the heart. Varies depending on the stage of life. Pulse rate (based on age): Newborn — 130 Radial pulse: Three months — 140 Six months — 130 One year — 120 Two years — 115 Three years — 100 Four to six years — 100 Carotid pulse: Eight years — 90 Twelve years — 85 Adult — 70 to 90 (average) 30 © CNM: Human Sciences ― Cardiovascular System II. BQ.  tachy- = rapid Cardiac Output brady- = slow Cardiac output is the volume of blood being pumped out by the heart per minute. On average this is 5 L per minute. Key definitions: Systole: The force that drives blood out of the heart (contraction). Diastole: Period of relaxation when the heart fills with blood. Tachycardia: Resting heart rate over 100 bpm. Bradycardia: Resting heart rate under 60 bpm. 31 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Blood Pressure The pressure exerted by circulating blood on the blood vessel walls. Constitutes one of the principal vital signs. The pressure progressively decreases away from the heart through arteries and then back toward the heart through veins. Normal ranges (NHS) = 90/60–140/90 mmHg. However, this varies from patient to patient and ranges differ between countries. Vasoconstriction increases blood pressure. Vasodilation lowers blood pressure. Highest priority for blood supply is to the brain and heart. 32 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Cholesterol Cholesterol is a vital compound for cell hepato- = liver structure and function. It is in every body cell. -cyte = cell Some of the key functions of cholesterol include: ‒ Cell membrane integrity (vital in the brain). ‒ Vitamin D and calcium metabolism. ‒ Sex hormones (e.g. oestrogen, testosterone). Cholesterol is acquired from liver cells (hepato- cytes produce 1000 mg daily) and from diet. Cholesterol is vital, but in excess might become be part of the pathogenesis of arterial plaque formation. As cholesterol is hydrophobic, it needs to be transported around the body — transported as lipoproteins. 33 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Lipoproteins Low-density lipoproteins (LDL): Carry 75% total cholesterol in blood, carrying it from the liver to cells of the body. When present in excess, LDLs have been associated with cholesterol deposition in arteries. However, LDL levels must be considered within the overall context of a presentation. High-density lipoproteins (HDL): Remove excess cholesterol from body cells and blood and transport it to the liver. Prevent accumulation of cholesterol in blood. 34 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Summary Quiz: 1. Label the heart’s conductive system on the image. 2. What is meant by ‘autorhythmic’? 3. What is the term describing a pulse rate over 100BPM? 4. What is meant by systole? Does this represent the top or bottom number when reading blood pressure? 5. What is the effect of the sympathetic nervous system on heart rate and strength of contraction? 6. What are the functions of cholesterol? 35 © CNM: Human Sciences ― Cardiovascular System II. BQ.  athero = plaque Atherosclerosis sclerosis = hardening Atherosclerosis = narrowing and hardening of arteries. Results in reduced blood flow through the affected artery, which negatively impacts the delivery of blood to target organs. Commonly affects vessels such as the coronary, carotid and cerebral arteries, the aorta, and major arteries of the extremities. The clinical manifestations of atherosclerosis (e.g., angina pectoris) are particularly common in Western populations and occur largely as a result of preventable factors. 36 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Atherosclerosis Pathophysiology Pathophysiology: 1. Damage of the vascular endothelium occurs, creating inflammation. 2. LDLs then deposit in the damaged tunica intima in an attempt to repair the damage, but are then oxidised, subsequently attracting phagocytes. 3. Macrophages surround the fatty material in an attempt to destroy it, and as a result, create foam cells. 4. Vascular smooth muscle cells proliferate. 5. A cap is formed over the atherosclerotic plaque to wall off the plaque from the blood. 37 © CNM: Human Sciences ― Cardiovascular System II. BQ. Atherosclerosis Pathophysiology 38 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Atherosclerosis Causes / risk factors: Hereditary, male sex, age (men > 45, women > 55), ethnicity (south Asian and African or Caribbean background). Hyperglycaemia (e.g. diabetes), obesity, hyperlipidaemia, hypertension, smoking, stress, sedentary lifestyle, excessive alcohol, trans fats, gut / oral dysbiosis, intestinal permeability. As indicated by the pathophysiology, the first step necessary for atherosclerosis to occur is endothelial damage. This is often due to factors such as free radicals / oxidative stress, hyperglycaemia and high blood pressure. 39 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Atherosclerosis Ischaemic = Inadequate blood supply to organ or tissue Clinical manifestations: Symptoms occur Angina pectoris / myocardial infarction ― ischaemic due to progressive blood vessel lumen heart pain (from thrombosis and embolism). stenosis (narrowing) Stroke / transient ischaemic attack (from thrombosis, embolism and haemorrhage). Allopathic treatment: BP meds, statins, surgery, stents, lifestyle changes. Natural approach: Reduce oxidative stress and blood pressure. Antioxidant-rich, plant-based diet, herbs (hawthorn, garlic, artichoke), exercise. Optimise glycaemic and lipid profile and dietary fibre. Beetroot. 40 © CNM: Human Sciences ― Cardiovascular System II. BQ.  hyper- = elevated Hypercholesterolaemia aemia = blood Hypercholesterolaemia = elevated blood cholesterol. Causes / risks: Clinical signs: ‘Familial’ (defect on chromosome 9, causing Xanthelasma inability to remove LDL from blood). Age-related (risk increases with age). Diet (high refined sugars, trans fats, table salt, etc.). Sedentary lifestyle. Corneal Arcus Diabetes mellitus (insulin resistance). Obesity. Excessive alcohol. Smoking. 41 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Hypercholesterolaemia Allopathic drug treatment: Statins (adverse effects: Muscle aches, insomnia, dizziness, fatigue, headaches, gastro-intestinal effects, cataracts). Induces a deficiency in CoQ10. Natural approach: Nutrition — increase omega-3 fats (increase HDLs) and fibre (increase cholesterol excretion). Niacin (B3), red rice yeast. Herbs (hawthorn, globe artichoke, garlic, dandelion). Exercise. Determine the cause — the body elevates cholesterol for a reason. 42 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Angina Pectoris Ischaemic heart disease due to obstruction dys- = difficulty or spasm of the coronary arteries. -pnoea = breathing The symptoms associated with angina result from the demands of the myocardium not being met by its blood supply; e.g. due to atherosclerosis or vascular spasm. Not a cardiac arrest or heart attack. Types of angina: Stable: Pain is precipitated by physical exercise. Unstable: Occurs randomly, even at rest. More severe and can last longer 43 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Angina Pectoris Signs and symptoms: Heavy, constricting chest pain, radiating to arms, neck, jaw and back. Eases on rest. Dyspnoea. Allopathic treatment: Acute relief: GTN (glyceryl trinitrate) sublingual (converted in the blood to nitric oxide  vasodilation). Long-term: Anti-hypertensives, low-dose aspirin, statins, stents. Natural approach: Increase nitric oxide (vasodilation): Vitamin D, arginine, beetroot, CoQ10. Magnesium. Herbs (turmeric, ginkgo, cayenne, hawthorn), exercise. 44 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Myocardial Infarction (Heart Attack) Necrosis (death) of myocardial tissue due to ischaemia. Usually due to blockage of a coronary artery by a thrombus. Infarcted areas produce scar tissue. The remaining tissue hypertrophies and can result in heart failure. infarction = dead Signs and symptoms: tissue formed from a failure of blood supply Severe chest pain (central, radiating to arms — usually left, jaw, neck and back). Pain can be sharp, tight, heavy; feeling of pressure. Does not improve on rest. Sweating, nausea, vomiting, pale and clammy skin, light-headed, SOB. Overwhelming anxiety / sense of impending doom. 45 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Myocardial Infarction (‘Heart Attack’) Diagnosis by ECG. Histological changes post Management: MI: The white area highlights necrosis of Oxygen. myocardial cells. Aspirin 300 mg orally and GTN spray. Angioplasty (unblocking of artery). Thrombolytic therapy (‘clot busters’) — forms plasmin which breaks cross-links of fibrin molecules. CPR. © CNM: Human Sciences ― Cardiovascular System II. BQ. 46  tachy- = quick Heart Failure brady- = slow The heart is impaired as a pump — failing The heart fails to to supply sufficient blood flow. pump blood forwards effectively Can be acute (medical so backflow of emergency) or chronic. fluid occurs CAUSES: Results from various cardiovascular conditions, e.g. coronary heart disease, hypertension, heart valve diseases. Linked to insulin resistance  impaired myocardial glucose utilisation. 47 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Heart Failure Right-sided failure: Left-sided failure: Increased vascular High blood pressure. Cause: resistance in the lungs (lung disease). Myocardial weakness. Back pressure from the left side of the heart (e.g., Valve problems. valve problems). Previous heart attack. Systemic oedema. Pulmonary oedema. Signs and Ascites. Congestion bronchitis. symptoms: Portal hypertension Cardiac asthma (often (oesophageal varices, most severe at night). haemorrhoids). 48 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Heart Failure Allopathic treatment: Acute (medical emergency): Sitting position, GTN sublingually, cardiopulmonary resuscitation (CPR), 100 mg aspirin. Chronic: ACE inhibitors, beta-blockers, diuretics. Digoxin. Surgery. Pacemaker. Advised aerobic exercise, smoking cessation, reduce alcohol. Natural support: Chronic: Address cardiovascular disease risk factors, optimise diet and correct nutritional deficiencies (e.g. CoQ10, Mg, vits. D, B1). Lose weight, reduce salt intake, exercise, herbs (e.g. hawthorn, ginkgo, turmeric, garlic). 49 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Stroke cerebro- = cerebrum / brain Also known as a cerebrovascular accident. 50% affect cerebral cortex (affects contralateral body). A disruption of blood supply to the brain. Four minutes of ischaemia causes irreversible cell damage. Characterised by rapidly developing signs of cerebral dysfunction, lasting more than 24 hours. CAUSES: Thrombus / embolus (80%) = ischaemic stroke. Haemorrhagic stroke — blood vessel damage; (i.e. following ruptured aneurysm). 50 © CNM: Human Sciences ― Cardiovascular System II. BQ.  F.A.S.T = Stroke Face, Arms, Speech, Time Symptoms are Signs and symptoms: contralateral to Sudden weakness, numbness / tingling, the side of brain dysphasia (difficulty speaking), loss of vision, suddendamage. severe headaches, confusion, unsteadiness. Diagnosis: CT scan, MRI scan. Treatment / support: Hospital, O2 therapy, aspirin, thrombolytic treatment, surgery. Nutrition and anti-coagulant herbs (e.g. turmeric). Homeopathy, ozone therapy, exercise. 51 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Transient Ischaemic Attack Temporary inadequacy of circulation to part of the brain: Gives similar clinical picture to stroke but lasts no longer than 24 hours. Can be warning sign for a full stroke. Causes: Same as stroke. Signs and symptoms: Same as stroke. Symptoms only last from a few minutes to a few hours. Impaired functions resolve within 24 hours 52 © CNM: Human Sciences ― Cardiovascular System II. BQ.  aneurysm = from Aneurysm Greek for widening Abnormal local dilations of arteries due to weakness of the vessel wall (often secondary to atherosclerosis). Common examples of aneurysms include: Abdominal aortic aneurysm (AAA): ‒ Asymptomatic until bursts (80% are fatal). ‒ Pulsatile abdominal mass and ‘tearing’ lower back pain. Berry aneurysm: ‒ Occurs in the centre of the cerebrum, causing a subarachnoid haemorrhage (presents as a severe headache). ‒ May lead to a haemorrhagic stroke. 53 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Hypertension Hypertension (high blood pressure) is a major risk factor for cardiovascular disease and cerebrovascular events. It is often asymptomatic. In the UK, it is defined as 140 / 90 mmHg or higher. Types: Primary (95%): Generally. lifestyle and family history. Obesity, age, smoking, sedentary, stress, excess alcohol, high table salt intake, nutritional deficiencies (e.g. magnesium). Secondary (5%): Secondary to another identifiable cause; e.g. renal disease, diabetes. 54 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Hypertension Allopathic treatment: Medication to reduce and maintain BP. E.g. ACE-inhibitors, diuretics, calcium channel blockers, beta-blockers. Weight loss (if appropriate), avoid salt, avoid caffeine, exercise, reduce stress and alcohol. Natural support: Diet, exercise and lifestyle are essential. Lose weight (if overweight), avoid table salt, avoid caffeine, regular exercise, reduce stress, magnesium, vits. C and D, B6, homocysteine = a type of B9, B12 (to lower homocysteine). amino acid in the blood. High Herbs — hawthorn, yarrow, lime flower, levels indicate increased risk mistletoe, dandelion leaf, acupuncture. of heart disease 55 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Hypertension Complications: Cardiovascular events, myocardial infarction, heart failure, aneurysm. Stroke. Chronic kidney disease (CKD). Vascular dementia. Premature death. Retinal (eye) damage. 56 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Heart Valve Pathologies Valve stenosis: Valve regurgitation: Fibrosis and Inadequate valve calcification of valve closure causing leading to leakage. obstruction to blood flow through heart chambers. To compensate the The heart myocardium hypertrophies and hypertrophies dilates to (enlarges)  heart accommodate failure. more blood  heart failure. 57 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Arrhythmias Arrythmia = any disorder of heart rate / rhythm. Bradycardia: Rate below 60. Physiological: Athlete. Pathological: Often caused by diseases affecting the SA or AV node (e.g. myocardial infarction). Tachycardia: Rate over 100. Fibrillation (e.g. atrial fibrillation): Irregular rhythm and force leading to inadequate blood supply. 58 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Atrial Fibrillation (AF) The most common cardiac arrhythmia. Irregular rhythm (uncoordinated, rapid, Normal small, local atrial contractions). Associated with stagnation of blood in the atria leading to thrombus formation and risk of embolism (stroke). Atrial Fibrillation Rhythm Palpate pulse to assess for irregularity. Patients may present with breathlessness, palpitations, dizziness, chest discomfort (or a stroke). 59 © CNM: Human Sciences ― Cardiovascular System II. BQ.  MEDICAL EMERGENCY Cardiac Arrest Conduction arrest (not a heart attack). Approximately 70% occur due Look for an absence of the to coronary heart disease. carotid pulse... Occurs when the heart develops an arrhythmia causing it to stop. Treatment: Cardiopulmonary resuscitation (CPR) to provide circulatory support until availability of defibrillation (application of an electric current to reset the electrical impulses running through the autorhythmic cells). 60 © CNM: Human Sciences ― Cardiovascular System II. BQ.  dys- = difficulty Endocarditis -pnoea = breathing An inflammation of the endocardium and valves. Usually a bacterial infection. Can spread from a dental infection (recent dental history?). Signs and symptoms: Non-specific symptoms: Fever, fatigue, muscle and joint aching, loss of appetite (flu-like symptoms). Dyspnoea and persistent cough. Signs: Osler’s nodes (red tender spots under skin of fingers), splinter haemorrhages (splinter appearance under nail bed), petechiae. 61 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Myocarditis Inflammation of the myocardium. Signs and symptoms: Chest pain, fatigue, fever, dyspnoea, palpitations, tachycardia. Cause: Normally a viral infection (consider the terrain). Side effect of COVID vaccination. Can also be due to a systemic inflammatory condition. Drug toxicity. Heavy metal toxicity. Treatment: Treat the underlying cause. Anti-inflammatory drugs. 62 © CNM: Human Sciences ― Cardiovascular System II. BQ.  peri = around Pericarditis cardia = heart -itis = inflammation Acute inflammation of the pericardium. Cause: Normally a viral infection (e.g. flu), but can be due to a systemic inflammatory condition, e.g. rheumatoid arthritis (RA). Signs and symptoms: Chest pain: Radiating to the back and relieved by sitting up and forward. Worsened by lying down or breathing deeply. Dyspnoea when reclining, low-grade fever, weakness, fatigue and feeling nauseous, dry cough, oedema (abdominal / leg). Pericardial friction rub (heard with auscultation). 63 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Pericardium Dissection As you can see the pericardium and diaphragm are attached. So think why Pericardium breathing might be painful in pericarditis… Diaphragm 64 © CNM: Human Sciences ― Cardiovascular System II. BQ.  effusion = collection of fluid Pericarditis within a space Allopathic treatment: Rest, anti-inflams / NSAIDs, antibiotics (if bacterial), steroids. In severe cases, surgical drainage. Natural support: Treat cause. Herbs and nutrition — antimicrobials, immune support, anti-inflammatory, acupuncture. Complications: 1. Constrictive pericarditis: Thickened and fibrotic pericardium. 2. Cardiac tamponade (pericardial effusion): Fluid collects in the pericardium, putting pressure on the heart, inhibiting it from filling completely. 65 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Deep Vein Thrombosis (DVT) Thrombus formation in the deep Pulmonary embolism veins of the legs. symptoms: Dyspnoea, Clot may dislodge and cause a chest pain, cough, pulmonary embolism. haemoptysis, Risks: tachycardia / Reduced blood flow (immobility, tachypnoea, pleural rub pressure on vein by tumour, long-haul flights). Varicose veins. Changes in blood (dehydration, polycythaemia, sticky platelets, oral contraceptive pill). Damage to blood vessel wall. 66 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Deep Vein Thrombosis (DVT) Signs and symptoms: Limb pain, calf swelling, tenderness along vein, distension of superficial veins, increased skin temperature and local redness (erythema). Ultrasound, D-Dimer test. Treatment: Complete rest. Heparin. Warfarin. Natural support: Anticoagulants: EFAs and vit. E, turmeric, ginkgo, garlic, hydration (good preventatives), homeopathy. 67 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Varicose Veins Incompetent valves cause pooling of the venous blood and chronically dilated superficial veins. Signs and symptoms: Aching and fatigue of legs, distended blue veins. Diagnosis: Doppler and ultrasound. Conventional approach: Leg elevation. Ablation (e.g. laser) to seal the vein, surgical excision. Natural approach: Vitamin C, rutin, herbs (e.g. horse chestnut), hydrotherapy, exercise. homeopathy (aesculus, hamamelis). Reduce weight if appropriate. 68 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Haemorrhoids Also referred to as ‘piles’. Dilated veins in the anal canal. Some prolapse, others do on straining, and some are permanent. Causes: Chronic constipation, chronic cough. Hypertension (portal hypertension). Obesity, pregnancy, abdominal bloating. Signs and symptoms: Bright red blood with bowel movements, protruding haemorrhoids, anal itching Natural support: See recommendations for varicose veins. E.g. horse chestnut, vitamin C, bioflavonoids, gotu kola. 69 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Raynaud’s Syndrome Intermittent attacks of ischaemia in extremities. Most common in women 30–40 years old. Causes: Extreme temperature, emotional stimuli. Rheumatological diseases; e.g. RA. Signs and symptoms: Vasospasm followed by hyperaemia. Pallor, cyanosis, redness. Pain. Treatment: Minimise stress, exercise regularly, keep warm, stop smoking. Topical nitrates. Herbs — ginger, capsicum (chilli), homeopathy, acupuncture. 70 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Oedema Excess fluid accumulation in interstitial spaces. Most common is pitting oedema. Pitting oedema: Non-pitting = lymphoedema or hypothyroidism. Volume of fluid kept in interstitial spaces is normally kept at 20% of body weight. Several processes can disturb this. Causes: Heart failure, renal disease, hepatic disease, drugs (long-term steroids, NSAIDs), DVT (late complication). 71 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Oedema Treatment: Treat the cause. Diuretics (encourage body water loss, but don’t address cause. Cause loss of minerals). Exercise, lose weight (if overweight). Raise legs, avoid prolonged standing Lymphatic drainage and massage. Herbs (nettle root, dandelion leaf). 72 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Ascites An excessive accumulation of fluid in the peritoneum. Causes: Liver cirrhosis (80%) — due to portal hypertension. Malignancy of liver, stomach, colon, pancreas, ovary. Heart failure. Constrictive pericarditis (fibrotic pericardium). Signs and symptoms: Abdominal distension and later discomfort. Nausea and suppressed appetite. Dyspnoea. Treatment: Allopathic: Diuretics may be implicated. Surgery (hepatic shunt). Alternative: Nutrition, herbs, homeopathy, acupuncture. 73 © CNM: Human Sciences ― Cardiovascular System II. BQ.  Differential Diagnosis of Chest Pain Differential diagnosis = the process of differentiating between two or more conditions that share similar presentations. Chest pain is an example of a symptom with many causes. For example, this could be: Cardiovascular: Stable / unstable angina Pulmonary: MI Pulmonary embolism Pericarditis Pneumothorax Pneumonia Musculoskeletal: Pleurisy Rib joint inflammation Rib fracture GIT: Inflammation of rib cartilage Gastro-oesophageal reflux Pancreatitis Nervous: Hepatitis Shingles © CNM: Human Sciences ― Cardiovascular System II. BQ. 74  Summary Quiz: 1. Outline the key steps involved in the formation of an atherosclerotic plaque. 2. What are the risk factors for atherosclerosis? 3. What is the difference between a stroke and TIA? 4. What is the usual cause of a myocardial infarction? 5. List THREE symptoms of pericarditis. 6. Compare the main symptoms of left- and right-sided heart failure. 7. Explain what is meant by an aneurysm. 8. What are the major risk factors of a DVT? 9. What are common causes of haemorrhoids? 10. Describe TWO possible complications of pericarditis. 75 © CNM: Human Sciences ― Cardiovascular System II. BQ.