Cardiovascular Disease Lecture Notes PDF

Cardiovascular disease Dr Brooke Coombes [email protected] Learning outcome • Describe the pathophysiology, presentation and management of hypertension, coronary heart disease and heart failure • Identify risk factors for cardiovascular disease • Describe the role of physiotherapy and exer...

Cardiovascular disease Dr Brooke Coombes [email protected] Learning outcome • Describe the pathophysiology, presentation and management of hypertension, coronary heart disease and heart failure • Identify risk factors for cardiovascular disease • Describe the role of physiotherapy and exercise in management of cardiovascular disease Cardiovascular disease (CVD) • Any disease of the heart or blood vessels • Major health problem & health care burden in Australia • 27% of deaths due to CVD • Greater impact on males, elderly, Indigenous Australians, people living in most disadvantaged areas Australian Institute of Health and Welfare 2019. Cardiovascular disease. Cardiovascular disease • Major causes of CVD death: • Coronary heart disease • Stroke • Heart Failure & Cardiomyopathy 1 Australian Institute of Health and Welfare 2019. Cardiovascular disease. Cat. no. CVD 83. Canberra: AIHW. Viewed 22 April 2020, https://www.aihw.gov.au/reports/heart-stroke-vascular-diseases/cardiovascular-healthcompendium Risk factors for CVD Non-modifiable risk factors Family history of CVD (2x) Diabetes (2-4x) Age Gender – men>pre-menopausal women; after menopause, risk is similar https://www.world-heart-federation.org/resources/risk-factors/ Risk factors for CVD Modifiable risk factors ↓ physical activity Smoking – damages lining of blood vessels Poor nutrition – high saturated fat High blood cholesterol (↑LDL) High blood pressure Overweight & obesity Stress, anxiety & depression Excessive alcohol consumption https://www.world-heart-federation.org/resources/risk-factors/ HYPERTENSION Blood pressure (BP) • BP is set by • Cardiac output (amount of blood pumped by each ventricle in 1 min) and • Peripheral resistance (resistance heart has to overcome to ensure blood flow to peripheral tissues) • The body uses multiple processes to control BP including • By regulating vasodilation and vasoconstriction • Excretion of salt and water à adjusts blood volume Hypertension • Is defined as systolic BP >140 and/or diastolic BP > 90 mmHg • ~20% of the population has high BP or requires BP lowering medication (Burt et al 1995) • Both numbers (SBP & DBP) are important, but after 65 years SBP is more important as isolated systolic hypertension is common Hypertension - Classification Classification of clinical blood pressure levels in adults DIAGNOSTIC CATEGORY* SYSTOLIC (mmHg) and / or DIASTOLIC (mmHg) Grade 1 (mild) HTN 140–159 +/- 90–99 Grade 2 (mod) HTN 160–179 +/- 100–109 Grade 3 (severe) HTN ≥180 +/- ≥110 Isolated systolic HTN >140 + <90 Hypertension Prolonged hypertension can lead to: • hypertrophy and/or heart failure, • myocardial infarction • Chronic low-grade inflammation • Stroke • kidney failure • sudden death Hypertension • “Silent killer” – most people will have no symptoms • For every increase of 20mmHg in SBP or 10mmHg in DBP, the risk of CV death doubles Hypotension • Low blood pressure =SBP < 90 mm Hg or DBP < 60 mm Hg • Symptoms include • Blurry vision • Dizziness, lightheadedness • Nausea • Trouble concentrating • May be asymptomatic Hypotension • Several types/causes e.g dehydration, blood loss, infection, pregnancy • Orthostatic hypotension (postural hypotension) • Sudden drop in BP when standing from a sitting position or after lying down • SBP drop > 30mmHg or DBP drop > 10mmHg • Causes include dehydration, long-term bed rest, pregnancy • Common in older adults Hypotension • Extreme low BP can lead to shock e.g from uncontrolled bleeding, severe infection • Symptoms include: • Confusion • Cold, clammy skin • Rapid, shallow breathing • Weak & rapid pulse Physical training and hypertension • Regular physical exercise can prevent hypertension or lower BP • Acute effects of physical activity include decrease in BP for 4-10 hours Pedersen 2015 Exercise as medicine Physical training in people with hypertension • Contraindications/ Precautions: • Regular physical activity should not begin if BP > 180/105 until after pharmacological treatment initiated • Caution with heavy weights which can increase pressure in left ventricle Pedersen 2015 Exercise as medicine CORONARY HEART DISEASE Coronary heart disease (CHD) • Also known as IHD, CAD, HD • Blood flow to the heart muscle is decreased causing ischemia • Most common cause is atherosclerosis à constricts coronary arteries • Other causes include heart valve disease, hypertrophic cardiomyopathy, severe hypertension, coronary artery spasm Atherosclerosis • Formation of fibrofatty lesions/plaque in the intimal lining of arteries = progressive inflammatory disorder • Artery walls become thickened and stiff Coronary heart disease (CHD) • Fibrofatty lesions can impair or obstruct coronary circulation which supplies the myocardium with oxygen and nutrients causing: • Myocardial ischemia (transient impairment or obstruction in blood flow) or • Myocardial infarct (myocardial cell death due to complete obstruction of blood flow) Coronary heart disease (CHD) • Commonly divided into 2 types of disorders • Acute coronary syndrome (ACS) • Spectrum ranging from unstable angina to myocardial infarction • Life threatening condition, require urgent thrombolytic therapy • Chronic ischemic heart disease • Recurrent and transient episodes of myocardial ischaemia • Stable angina Angina • Chest pain due to ischemia of the heart muscle • Generally due to obstruction or spasm of the coronary arteries • Presentation: • Constricting or squeezing pain in the pericardial or substernal area of the chest, possibly radiating to the arms, jaw or thorax Stable Angina • Usually occurs during activity (exertion) e,g. walking uphill • Usually goes away with rest or angina medication • Is predictable • Chest pain typically lasts short time (<5mins) Unstable Angina • Sudden-onset angina at rest or minimal exertion • Lasts longer than 20 mins • Not relieved with medications • More severe, prolonged or increased frequency than previously experienced • Medical emergency as may herald myocardial infarction Myocardial infarction (MI) • Heart attack • Myocardial ischemia sufficiently severe to cause permanent damage to heart muscle (myocardium) • Severity depends on location of obstruction & time from onset of symptoms to treatment Myocardial infarction (MI) • Results in release of detectable quantities of serum cardiac markers • Biochemistry – elevated Troponin-I • If ECG changes (ST elevation MI) = STEMI • If no ECG changes = NSTEMI Myocardial infarction (MI) • Symptoms • Abrupt onset severe chest pain • Crushing pain usually substernal & radiating to the left arm, neck, jaw • Gastrointestinal complains (nausea & vomiting) • Complaints of fatigue & weakness • Tachycardia, anxiety • Pale, cool and moist skin Myocardial infarction (MI) • Medical management • Thrombolytic therapy • Revascularisation interventions: • Coronary artery bypass grafting (CABG) • Percutaneous coronary intervention (PCI) • Stents HEART FAILURE Heart failure (HF) • Condition where heart is unable to pump enough blood flow to meet the metabolic needs of the peripheral tissue (Braunwald 2008) • Can be divided into • Acute vs chronic HF • Based on severity (NYHA class) • Left-sided (most common) vs right-sided HF