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NCLEX RN Preparation Program. Cardiovascular Disorders Module 5, Part 2 of 3. Introduction The heart and the circulatory system comprise one of the most essential parts of the body. Failure to function results in death of the organism. Cardiovascular System.
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NCLEX RN Preparation Program Cardiovascular Disorders Module 5, Part 2 of 3
Introduction The heart and the circulatory system comprise one of the most essential parts of the body. Failure to function results in death of the organism. Cardiovascular System Photo Source: National Heart, Lung and Blood Institute (NHLBI) http://www.nhlbi.nih.gov/health/dci/Diseases/arr/arr_howheartwork.html
Layers: Pericardium Fibrous Serous Pericardium Epicardium Myocardium Endocardium Gross Structure of the Heart
Heart, a muscular organ divided by a septum into two halves. Right or venous chamber and left or arterial chamber. Right Chambers Right Atrium Right Ventricle Left Chambers Left Atrium Left Ventricle Chambers of the Heart
Right Coronary Artery Left Coronary Artery Left anterior descending Circumflex Coronary Blood Supply Photo Source: U.S. National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program
Valves of the Heart • Valves are strong membranous openings that provide one-way flow of blood. • Atrioventricular valves – prevent backflow of blood from ventricles to atria during systole. • Tricuspid • Mitral • Semilunar valves – prevent backflow from the aorta and pulmonary arteries into the ventricles during diastole. • Pulmonic • Aortic
Valves of the Heart Photo Source: U.S. National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program
Conduction system • Specialized tissue that allows rapid transmission of electrical impulses through the myocardium • Sinoatrial node – main pacemaker of heart. Normal rhythmic, self-excitatory impulse is generated.
Conduction system Photo Source: St. Francis Hospitals & Health Centers, http://www.stfrancishospitals.org/DesktopDefault.aspx?tabid=72&Class=Test&pageid=P07973
Gross Structure of Vasculature • Arteries: transport blood under high pressure to body tissues • Precapillary sphincters • Arteriovenous shunts • Capillaries – exchanging fluid and nutrients between blood and interstitial space. • Veins: acts as conduits for transport of the blood from tissues back to heart
Physiology of the Heart • Contraction – shortening or increase in muscle tension. Utilizes chemical energy to do the work of contraction • Cardiac Muscle Principle: • Frank Starling Law: the greater the heart is filled during diastole, within physiological limits, the greater the quantity of blood pumped into the aorta and pulmonary artery.
Autonomic Nervous System Control • Cardiac Muscle • Sympathetic (Adrenergic) • Parasympathetic (Cholinergic) • Systemic blood Vessels • Sympathetic – vasoconstriction • Parasympathetic – vasodilation
Baroreceptor Reflex (Pressoreceptors) • Located in the walls of large systemic arteries • Rise in pressure results in baroreceptors transmitting signals to CNS (Central Nervous System) to inhibit sympathetic action • Other signals, in turn, sent to circulatory system to reduce pressure back to normal. • Result: decreased heart rate, vasodilation, decreased BP.
Other Chemical Controls of Blood Pressure • Kidney • Adrenal cortex - aldosterone • Renin-angiotensin system • Antidiuretic hormone (vasopressin)
Pain Dyspnea Cyanosis Fatigue Palpitations Syncope Hemoptysis Edema Condition of Extremities System AssessmentEvaluate Patient’s History
Evaluate veins and arterial pulses through inspection/palpation • Veins • Neck veins • Arm and hand veins • Leg and foot veins • Arteries • Central • Peripheral pulses
Auscultatelung sounds • Lungs • Listen for bibasilar crackles – if present, suspect Congestive Heart Failure (CHF) Photo Source, Wikimedia Commons, Creative Commons, http://commons.wikimedia.org/wiki/Image:X-ray_lung_consolidation.jpg
Auscultate heart sounds • Heart sounds – frequency, pitch, intensity, duration • Murmurs • Systolic • Diastolic • Pericardial friction rubs
Other parameters to assess • Arterial pressure • Carotid blood vessels for bruit • Palpate and percuss thorax • Evaluate chest x-rays • Assess lung sounds
Laboratory Studies Cardiac Enzymes CK-MB LDH Troponin Myoglobin BNP CBC Blood coagulation factors Serum lipids Electrolytes K, Na Calcium Phosphorus Magnesium BUN Blood glucose Diagnostic Tests & Procedures
Diagnostic Procedures • Electrocardiogram • Central Venous Monitoring • Cardiac Catheterization • Echocardiography • Angiography • Chest x-rays
Acute Coronary Syndromes • Coronary Artery Disease (CAD) • Narrowing or obstruction of one or more coronary arteries as a result of atherosclerosis, an accumulation of lipid-containing plaque in the arteries. Photo Source: National Heart, Lung and Blood Institute (NHLBI), http://www.nhlbi.nih.gov/health/dci/Diseases/Cad/CAD_WhatIs.html
Pathophysiology • Atherosclerosis - fat deposited in intima of arterial wall • Inflammatory response begins • Macrophages inflitrate area to ingest lipids, then die • Smooth muscles cells within the blood vessel cover the area with fiber and plaque is formed. • If the plaque is thin, the lipid center may grow, rupture, become a thrombus
Myocardial Ischemia / Angina Pectoris • Decreased oxygen to heart • Exercise-induced chest pain • Unstable angina • Other risk factors
Coronary Artery DiseaseMyocardial ischemia CLINICAL MANIFESTATIONS: • May be asymptomatic unless ischemia occurs • Chest pains or pressure, may radiate to jaw, back, shoulder • Palpitations, weakness • Dyspnea • Syncope • Nausea • Excessive fatigue • EKG changes (T wave inversion)
Coronary Ischemia/Angina Silent angina - no symptoms, but EKG changes. Often occurs in diabetic patients with CAD.
Teaching for Angina • Rest at onset of chest pain • Take one nitroglycerin, repeat 2 more prn • No relief by 3rd, call 911 • Previous angina with particular activity, take nitroglycerin prior to activity
Unstable Angina • Oxygen: 2-4L nasal cannula • Nitroglycerin • Morphine • Aspirin • Baseline vital signs • 12 lead EKG • Monitor for dysrhythmias, heart failure
Myocardial Infarction Photo Source: National Heart, Lung and Blood Institute (NHLBI), http://www.nhlbi.nih.gov/health/dci/Diseases/Cad/CAD_WhatIs.html
MI: Signs and Symptoms • Pain • Nausea • Impending doom • Diaphoresis • Dyspnea • Dysrhythmias
12-lead EKG • Normal • Ischemia • Injury • Acute infarct • Old infarct
LABS • Myoglobin – non specific • Troponin • CK-MB • BNP = CHF
Collaborative Management • Immediate assessment • Vital signs with oxygen saturation • 12-lead EKG • Cardiac enzymes • Chest x-ray • Electrolytes – K+ & Mg++ • Immediate treatment – “MONA” • Beta blockers?
MONA • Acronym from Advanced Cardiac Life Support (ACLS) though order is ONMA. • O = Oxygen 2-4 liters per nasal cannula • N = Nitroglycerin (if not already tried outside hospital); relieves pain • M= Morphine relieves pain, decreases anxiety, increases venous pooling (to reduce cardiac workload) • A = Aspirin prevents platelet aggregation at the site of obstruction
Reperfusion Strategies • Thrombolytics • Percutaneous Transluminal Coronary Angioplasty (PTCA) • Stent Procedure Photo Source: National Heart, Lung and Blood Institute (NHLBI), http://www.nhlbi.nih.gov/health/dci/Diseases/Cad/CAD_WhatIs.html
Post-PCTA Care • Monitor V/S • Assess distal pulses • Bed rest with limb straight for 6 – 8 hours • Anticoagulants/antiplatelet agents – prevent thrombus formation • Monitor IV nitroglycerin – prevent coronary artery spasms • ASA once a day permanently • Assist planning lifestyle modification
Bed rest for 24 to 36 hrs Pain control Monitor rhythm Assess for new murmurs Monitor potassium, magnesium Monitor for heart failure Gradual increase of activities Acute Myocardial Infarction
Rehabilitation • Diet • Progressive exercise • Change modifiable risk factors • Weight loss • Stress reduction • Lipid-lowering drugs • Anti-hypertensives • Aspirin
Coronary Artery Bypass Graft (CABG) • Bypass grafts sewn from aorta to below area of blockage • Fluid overload • Pacemaker? • Bleeding • Atrial fibrillation
Nursing Management Control pain Early ambulation Incentive spirometer Change dressings: watch for infection Monitor: VS, lungs, heart, weight, I&O, labs, EKG
Complications • Stroke • Tamponade: pulsus paradoxus • Bleeding • Dysrhythmias • Post-cardiotomy syndrome
Cardiac Dysrhythmias • Normal Sinus Rhythm/Regular Sinus Rhythm • Rhythm originates from the SA node • Atrial and ventricular rhythms are regular • Rates are : 60- 100 beats per minute.
Cardiac Dysrhythmias • Sinus bradycardia • Atrial and ventricular rates below 60 beats per minute • Treatment may be necessary if symptomatic • Note: low rates may be normal for some patients.