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Dysrhythmias. Objectives. Describe basic heart dysrhythmias Explain the pathophysiology of dysrhythmias Describe nursing interventions in caring for clients with heart dysrhythmias. Terms. Automaticity - The inherent ability of the myocardium to generate it’s own electrical impulse
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Objectives • Describe basic heart dysrhythmias • Explain the pathophysiology of dysrhythmias • Describe nursing interventions in caring for clients with heart dysrhythmias
Terms • Automaticity- The inherent ability of the myocardium to generate it’s own electrical impulse • Depolarization- Electrical activity that stimulates the heart to contract • Repolarization- Electrical activity that signals the myocardium to relax
The Conduction Pathway Flow of Electricity through the Heart Sinoatrial Node (SA node “sinus”) → Atrioventricular Node (AV node) → Bundle of HIS (Right and Left bundle branches) → Purkinje Fibers Any disturbance in the flow of electricity will cause a change in the heart rhythm and rate.
Dysrhythmias • A regular rate may indicate normal electrical conduction, but could be an arrhythmia; it must be diagnosed by ECG/EKG. Most important is to know the patient’s history and their tolerance. • Example: Atrial Flutter and Ventricular Tachycardia have regular rates
Dysrhythmias • An irregularly irregular rhythm or a regularly irregular rhythm may indicate abnormal conduction which may be benign; must be diagnosed by ECG. Most important is to know the patient’s history and their tolerance. • Examples: Sinus Arrhythmia and Premature Ventricular Contractions
Cardiac Dysrhythmias • The Normal Electrical Impulse • P wave = atrial depolarization • QRS = ventricular depolarization • T wave = ventricular repolarization
Normal Sinus Rhythmaka NSR or SR Normal Sinus Rhythm: HR 60-100
Sinus Tachycardia • Rapid regular rhythm originating in the SA node • HR 100 and up • Multiple causes
Sinus Tachycardia • Causes: • Anxiety • Fever • Exercise • Shock • Medication • Excessive caffeine • Tobacco use • Recreational drugs
Sinus Tachycardia • Clinical Manifestations: • Occasional palpitations • Hypotension • Angina • Other CV disease • Many patients are asymptomatic • Medical Management: directed at the primary cause
Sinus Tachycardia Treatment • Anxiolytics • Fever reducer • Fluids • Beta Blockers • Thyroid workup • Insulin • Avoiding triggering stimulants
Sinus Bradycardia • Slow, regular rhythm (<60 bpm) • Originates in SA node • Multiple causes • Worrisome if patient shows s/s of low cardiac output
Sinus Bradycardia • Causes: • Sleep • Vomiting • Intracranial tumors • MI • Drugs (esp. digitalis toxicity) • Vagal stimulation • Hypothermia • Endocrine disturbances
Sinus Bradycardia • Clinical Manifestations: • Fatigue • Lightheadedness • Syncope • Some patients are asymptomatic • Medical Treatment: directed toward the primary cause and maintain cardiac output • Atropine may be prescribed to ↑ output • Temporary or permanent pacemaker
Sinus Bradycardia Treatment • If related to brain- EMERGENCY- this is a late sign of increased ICP! • Otherwise, treat if symptomatic: • Hold affecting medications • Warm • Atropine or Epinephrine • Pacemaker
Supraventricular Tachycardiaaka SVT • Sudden onset of rapid heartbeat • Rate 150-250 bpm, does not fluctuate with activity • Originates in atria • Multiple causes • May be idiopathic
Supraventricular Tachycardia • Causes: • Drugs, alcohol • Mitral valve prolapse • Emotional stress • Smoking • Hormone imbalance
Supraventricular tachycardia • Clinical manifestations: • Palpitations • Lightheadedness • Dyspnea • Anginal pain • Medical Management: • How well does the pt. tolerate the dysrhythmia • Focus: ↓ HR; eliminate underlying cause
SVT Treatment DO NOT USE CAROTID SINUS PRESSURE or CAROTID MASSAGE! • Vagal Stimulation • Gagging • “Bearing down” • Valsalva maneuver • Holding breath while bearing down • Other maneuvers • Coughing/suctioning • Ice water in face
SVT Treatment • Medications • Adenosine/adenocard, antiarrhythmics, AV node blocking agents • Direct Current Cardioversion • Catheter Ablation
Atrial Fibrillation • Disorganized atrial activity quivering • Ventricle may respond at various rates • An irregularly irregular rhythm • Risk of blood clot if left untreated • Causes
Atrial Fibrillation • Causes: • Cardiac surgery • Long-standing HTN • Atherosclerosis • Pulmonary embolism • Heart Failure • COPD • cardiomyopathy
Atrial Fibrillation • Clinical Manifestations: • Pulse deficit • Palpitations • Dyspnea • Lightheadedness • Fatigue • Angina
Atrial Fibrillation • Medical management: • Treat the irritability of the atria • Slow the ventricular response • Correct the primary cause • Goal of therapy: PREVENT THROMBI
Treatment of AFib • Prevention of thrombi causing an embolism is a major concern • Heparin/Coumadin • Rate Control • AV node Blocking agents • When threat of thrombi diminished • Conversion • Antiarrhythmics • Direct Current Cardioversion (echo first) • Catheter Ablation
Treatment of AFib • Approximately 60-70% of patients with persistent AFib will be treated with anticoagulants and rate control only • Goal of anticoagulation: maintain the INR between 2-3 • Coumadin therapy is dangerous and at times difficult to manage • Benefit of therapy must outweigh risk of therapy • Benefits • Risks
Coumadin Anticoagulants – Coumadin • Inhibits Vitamin K based synthesis clotting factors in liver • Compliance is extremely important • Measured by Protime and INR • Normal Protime: 12-14 seconds • Normal INR: 1.0
Coumadin • Normal Protime for an anticoagulated patient is 1.5 to 2.5 times normal • Normal INR for an anticoagulated patient should be about 2-3.5 (requires frequent testing) • Onset is 1-3 days, peak 3-5 days, effect wears off 3-5 days • Avoid inconsistent intake of foods with vitamin K (i.e. leafy greens) • Reversal agents: Vitamin K and Plasma
AFib Treatment • Other Factors to consider for coumadin: • Client’s cognitive status and memory, or support system • Client’s mobility status: Fall Risk?!?! • Other medications • Meds affecting coagulation • Fluorquinolones (Levaquin and Cipro) • Antifungals • Depakote • Meds that cause orthostatic hypotension or dizziness
AFib Treatment • Rate Control • Sometimes the ventricular rate (HR) is labile • Dosages of AV Node blocking agents may need to be very high • If the client cannot maintain an appropriate ventricular rate may need pacemaker • Example: • On Metoprolol 50mg BID, client has HR ranging from 85-120. On Metoprolol 75mg BID, client has HR of 40. • Client will receive pacemaker to keep HR above a certain number (60) and metoprolol dose of 75 mg.
Atrioventricular (AV) Block • Impulse is slowed or not received in the ventricles from the SA node • Symptoms can range from none to life threatening First Degree AV Block: PR interval longer than 0.20 Heart rate normal Symptoms: Usually none Treatment: Not necessary Causes: MI, Heart Surgery, or medications that depress the SA node, atherosclerosis, digitalis toxicity First Degree Heart Block: PR=0.28 seconds (Normal = .16-0.2 seconds) Conduction delayed
Second Degree Heart Block Second Degree Heart Block: Conduction fails to reach Ventricles PR interval may progressively become longer until a beat is dropped or the PR interval remains the same, but beats are dropped. HR is usually 40-60 BPM Symptoms range from none to dizzness/lightheadedness, SOB, weakness, or confusion Causes: Medications affecting the SA node or the AV node, MI, heart surgery Treatment: Hold medications, pacemaker if needed
Third Degree Heart Block HR 20’s-40. Intervals vary Symptoms: Low cardiac output! Causes: MI, heart surgery, medications Treatment: Pacemaker Most likely to require a pacemaker Third Degree Heart Block: Signals from the SA node are not reaching the ventricles, so the ventricles have their own escape rhythm. ‘Everyone’ is talking but no one is communicating.
Premature Ventricular Contractions (PVCs) • Abnormal beats originating in the ventricles • Early ventricular beats • Symptoms range from none to life threatening depending on frequency of PVCs
PVC’s • Causes: • Irritability of ventricle musculature • Exercise, stress • Electrolyte imbalance • Digitalis toxicity • Hypoxia • MI
PVC’s • Clinical Manifestations • Some – asymptomatic • Palpitations, lightheadedness, weakness • PVCs may be a single event or may last long enough Vtach death • Medical Management • Treat the underlying heart condition • Symptomatic PVC’s: beta-adrenergic blockers such as Coreg; antianginals, Inderol; antidysrhythmics: Amiodarone
Ventricular Tachycardia (V-tach) • 3 or more PVCs in a row • Ventricular rate >100 bpm • Multiple causes Patient may or may not have a pulse with this rhythm
V-tach Management • With pulse: • ABC’s, Vitals • If stable- • Vagal/Valsalva maneuver’s • Antiarrhythmics • Defibrillation • Unstable • Synchronized Defibrillation • Without pulse • BLS • Unsynchronized defibrillation
Ventricular Fibrillation(V-fib) • Quivering of the ventricles • Heart is not beating, therefore there is no pulse • Cause: MI • BLS then Unsynchronized defibrillation is usually the only way to convert this rhythm, although antiarrhythmics are given.
Management of the Dysrhythmia Patient • ABCs (Airway, Breathing, Circulation) first!!! • Management will focus on treatment of the underlying cause if known Goalof any therapy is to preserve and maximize cardiac output
Management of the Dysrhythmia Patient • Implantable cardioverter defibrillator • Device implanted in atrium that will automatically sense and shock VT or VF • Often coupled with a pacemaker • Pacemaker • Can be temporary or permanent (implantable) • Maintains a certain minimal heart rate
Permanent Implanted Devices • STERILE PROCEDURE • Performed by cardiologist • Overnight hospital stay • Affected arm in sling • Do not lift over head • Infection can be EXTREMELY SERIOUS
Management of the Dysrhythmia Patient • Medications (Not a Comprehensive List) • Beta-blockers – metoprolol, propranolol • Calcium channel blockers – diltiazem • Class III antiarrythmic- Amiodarone, Lidocaine • Adenosine • Digoxin
Nursing Interventions Patient Teaching
Assessment • DATA COLLECTION • Subjective • Focus on specific cardiac symptoms • Chest pain, SOB, palpitations, exercise intolerance, nausea • Objective • Vital Signs • 12 lead EKG • Apical Pulse • Observe for signs of decreased cardiac output • Decreased peripheral pulses, decreased capillary refill, respiratory distress, pallor, ashen color, cyanosis
Nursing Interventions • Focus on: • Symptomatic relief (anxiety, pain, cardiac s/sx) • Promote comfort • Emergency action as needed • Patient Teaching • During Nsg. Assessment: • Assess the apical (not radial pulse) to obtain accurate rate Take the pulse for 1 minute
Nursing Interventions • Asses patient’s anxiety and degree of understanding • Note verbal and nonverbal expressions re: dx., procedures, and treatments • Explanations as needed • Medication administration • Oxygen administration prn • Maintain quiet environment
Patient Teaching • Avoid/stop smoking • Medication therapy and its purposes • Taking his/her pulse, BP • Exercise within prescribed limits by MD • Energy conservation techniques • Stress management