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Cardiovascular Disorders. Objectives. List and define the five diagnostic tests for CV function Define blood pressure, units used to measure, systolic vs. diastolic numbers, normal BP Define pulse, common sites for measurement, normal pulse
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Objectives • List and define the five diagnostic tests for CV function • Define blood pressure, units used to measure, systolic vs. diastolic numbers, normal BP • Define pulse, common sites for measurement, normal pulse • Differentiate between cardiovascular disorders in terms of pathophysiology, etiology, risk factors (where listed), s/s, treatment
Overview • Diagnostic Tests for Cardiovascular Function • General Treatment Measures for Cardiac Disorders • Blood Pressure & Pulse • Arterial Diseases • Hypertension • Coronary Artery Disease (CAD) • Atherosclerosis • Myocardial Infarction (MI) • Cardiac Arrhythmias • Sinus node abnormalities • Atrial conduction abnormalities • Cardiac arrest • Congestive Heart Failure (CHF) • Shock
ECG Monitors arrhythmias, MI, infection, pericarditis Studies conduction activation and systemic abnormalities Ausculation Studies heart sounds using stethoscope Exercise stress test Assess general cardiovascular function Checks for exercise-induced problems Chest X-ray Film Shows shape, size of heart Evidence of pulmonary congestion associated with heart failure Nuclear imaging Diagnostic Tests for Cardiovascular Function
Diagnostic Tests • Cardiac Catheterization • Visualize inside of heart, measure pressure, assess valve and heart function • Determine blood flow to and from heart
Diagnostic Tests • Angiography • Visualization of blood flow in coronary artery • Obstruction assessed and treated • Basic catheterization • Balloon angioplasty
Diagnostic Tests • Doppler Studies • Assessment of blood flow in peripheral vessels • Microphone records sounds of blood flow • Can detect obstruction • Blood tests • Assess triglyceride and cholesterol levels • Electrolytes • Hb, hematocrit, cbcs • Arterial Blood Gas Determination • Essential for pts with shock, MI • Check current oxygen levels, acid-base balance
Dietary modification Regular exercise program Quit smoking Drug therapy General Treatment Measures for Cardiac Disorders
Blood Pressure • Force exerted by blood against the inner walls of the vessels • Primary role is in the arterioles and arteries (greatest pressure) • In capillaries and venules, BP less and blood flow movement is slower • BP = arterial pressure
(Arterial) Blood Pressure • High pressure to low pressure • Highest pressure – Systole • Pumping action of heart – pushes high vol. of blood during each beat into small space inside aorta elastic walls of aorta stretch, maximum value is reached (systolic pressure) • Ex:120/80 (120 is systolic pressure)
(Arterial) Blood Pressure cont. • Lowest pressure – Diastole • Relaxation of the heart – Blood leaves the aorta, traveling to smaller vessels walls of aorta recoil to normal shape and pressure drops (diastolic pressure) • Ex: 120/80 (80 is diastolic pressure)
(Arterial) Blood Pressure cont. • Measurement • Column of mercury (Hg), moves in relation to pressure changes that are measured in millimeters of mercury (mm Hg) • Ex: BP is 72 mm Hg, the pressure is great enough to life a column of mercury a distance of 72 mm
Pulse • As blood moves from aorta to small vessels, blood flow through arteries causes elastic walls of arteries to expand and recoil • Rhythmic movement is known as the pulse • Places to feel pulse • Wrist – most common • Carotid artery (neck)
Arterial Diseases: Hypertension—Pathophysiology • Increased bp • Insidious onset, mild symptoms and signs • 3 major categories • Essential (primary) • Secondary • Malignant • Can be classified as diastolic or systolic • Develops when bp consistently over 140/90 • Diastolic more important
Hypertension—Pathophysiology • Over long time, high bp damages arterial walls • Sclerosis, decreased lumen • Wall may dilate, tear • Aneurysm • Areas most frequently damaged: • Kidneys, brain, retina • End result of poorly controlled hypertension: • Chronic renal failure • Stroke • Loss of vision • CHF
Hypertension—Etiology • Increases with age • Males more freq and severe • Genetic factors • High sodium ion intake • Excessive alcohol • Obesity • Prolonged, recurrent stress
Hypertension—Signs and Symptoms • Asymptomatic in early stages • Initial signs vague, nonspecific • Fatigue, malaise, morning headache
Hypertension—Treatment • Treated in sequence of steps • Life style changes • Mild diuretics, ACE inhibitors • One or more drugs added • Pt compliance is an issue • Prognosis depends on treating underlying problems and maintaining constant control of bp
Coronary Artery Disease • Occurs when coronary arteries that supply heart muscle become blocked • Partially blocked causes angina • Fully blocked causes a myocardial infarction or heart attack
CAD: Pathophysiology • Usually caused by atherosclerosis • Fatty material and plaque build up on walls of arteries • Cause narrowing blood flow slowed
CAD and Atherothrombosis • Because of reduced blood flow and rough edges of plaque, blood clot can form • Clot can block artery or plaque can rupture which can also cause blood to clot (atherothrombosis) • Atherothrombosis leads to MI, ischemic stroke, and other conditions
Risk Factors for Coronary Artery Disease • Age: • Male > 45 years • Female > 55 years or premature menopause without estrogen replacement therapy • Family History of premature disease • Male first-degree relative <55 years • Female first-degree relative < 65 years)
Risk Factors for Coronary Artery Disease cont. • Hypertension • Appears to weaken the artery wall at points of high pressure leading to injury and invasion of cholesterol. • Cigarette Smoking • #1 cause of preventable death in US • 1 in 5 CHD deaths attributable to smoking • Combination of BC pills and smoking
Risk Factors for Coronary Artery Disease cont. • Diabetes • 50% of deaths related to DM is due to CHD • Inactivity • Sedentary person has 2x risk for developing CHD as a person who is active
Risk Factors for Coronary Artery Disease cont. • Abnormal Blood Lipids • LDL Cholesterol (low density lipoprotein) • “Lethal” (bad) cholesterol • HDL Cholesterol (high density lipoprotein) • “Healthy” (good) cholesterol
Atherosclerosis—Treatment • Decrease cholesterol and LDL • Decrease sodium ion intake • Control primary disorders • Quit smoking • Oral anticoagulant • Surgical intervention • Percutaneous transluminal coronary angioplasty (PTCA) • Cardiac catheterization • Laser beam technology • Coronary artery bypass grafting
CAD: Myocardial Infarction—Pathophysiology • Heart attack • Coronary artery completely obstructed • Deprives heart muscle of blood and oxygen causing injury to heart muscle • Cardiac ischemia • Causes chest pain/discomfort (angina pectoris) • Silent ischemia • Ischemia without any pain • Can have heart attack with no prior warning
MI—Pathophysiology cont. • Function of myocardium contraction and conduction quickly lost • Oxygen supplies depleted • 1st 20 minutes critical • Time Line • 1st 20 min critical • 48 hrs inflammation begins to subside • 7th day necrosis area replaced by fibrous tissue • 6-8 weeks scar forms
MI—Signs and Symptoms • Pain • Sudden, substernal area • Radiates to L arm and neck • Less severe in females • Pallor, sweating, nausea, dizziness • Anxiety and fear • Hypotension • Low grade fever
MI—Complications • Arrhythmias • 25% pts sudden death after MI • Due to ventricular arrhythmias and fibrillation • Heart block • Premature ventricular contraction (PVCs) • Cardiogenic shock • CHF
MI—Treatment • Rest, oxygen therapy, morphine • Anticoagulant • Drugs • Cardiac rehabilitation • Prognosis depends on site/size of infarct, presence of collateral circulation, time elapsed before treatment • Mortality rate in 1st year • 30-40% due to complications, recurrences
Cardiac Arrhythmias • Alteration in HR or rhythm • ECG monitors • Holter monitors • decreases efficiency of heart’s pumping cycle • Slight increase in HR increases CO • Very rapid HR prevents adequate filling in diastole • Very slow HR reduces output to tissues • Irregular contraction inefficient • Interferes with normal filling/emptying cycle
CA: Sinus Node Abnormalities • Brachycardia • Regular but slow HR • Less than 60 beats/min • Results from vagus nerve stimulation or PNS stimulation • Tachycardia • Regular rapid HR • 100-160 beats/min • Exercise, fever, compensation for low blood volume
CA: Atrial Conduction Abnormalities • Premature Atrial Contractions (PAC) • Extra contraction or ectopic beats of atria • Irritable atrial muscle cells outside conduction pathway • Interfere with timing of next beat • Atrial flutter • HR 160-350 beats/min • AV node delays conduction • Slower ventricular rate
Treatment of CA • Cause should be determined and treated • Easiest to treat are those due to meds • SA node problems may require a pacemaker • Some may require defibrillators
Cardiac Arrest • Cessation of all activity in the heart • No conduction of impulses (flat line) • May occur b/c: • Excessive vagal nerve stimulation (decreases heart) • Drug toxicity • Insufficient oxygen to maintain heart tissue • Blood flow to heart and brain must be maintained to resuscitate
CHF—Pathophysiology • Heart failure, cor pulmonale • Heart unable to pump sufficient blood to meet the needs of the body • Most commone- cardiac output is low and body becomes congested w/fluids
CHF—Etiology • Causes • MI and other forms of ischemic heart disease • HTN • Valvular heart disease • Cardiomyopathy • Term “heart failure” incorrectly used to describe other cardiac-related illnesses (MI, cardiac arrest) these can cause heart failure but not equiv. to it
CHF—Signs and Symptoms • Chest discomfort • Usually lasts >several mins or goes away and comes back • Can feel like: • Uncomfortable pressure – “elephant on my chest” • Squeezing • Fullness • Pain • Discomfort in other areas of upper body • One or both arms • Back • Neck • Stomach • Jaw