Cardiovascular System Dysrhythmia Interpretation and Management PDF

10/20/2023 DISORDERS OF THE CARDIOVASCULAR SYSTEM NP02L020 ELO B · Version 2.0...

10/20/2023 DISORDERS OF THE CARDIOVASCULAR SYSTEM NP02L020 ELO B · Version 2.0 Dysrhythmia Interpretation and Management Foundations and Adult Health Nursing, 8th Ed., pp. 1528-1535 Introduction to Critical Care, 8th Ed., pp. 105-113; pp. 116-145; pp, 311-314 1 ENABLING LEARNING OBJECTIVE Determine approaches to nursing care of patients with a cardiac dysrhythmia. 2 ELECTRICAL CONDUCTION SYSTEM 3 1  10/20/2023 CHARACTERISTICS Automaticity Irritability History Hormones, ion concentration affects: Conduction of messages around the heart Initiation of heartbeat Coordinator of beating between atria and ventricles 4 5 CONDUCTION PATHWAY SA NODE AV NODE BUNDLE OF HIS PURKINJE FIBERS Origin of normal Slows the impulse Conduction fibers Muscle fibers beneath impulse Rate 40 bpm Divide into bundle the endocardium Pacemaker of the heart branches Result in contraction and Rate 60-100 bpm emptying of ventricles Rate 20-40 6 2  10/20/2023 IMPULSE GENERATION Sinoatrial node (SA node) Impulse passes through Rate 60-100 bpm Bundle of His Located in upper part of atrium Divide the right and left bundle Transmission through the atria branches  atrial contraction Extend down the side of interventricular septum Atrioventricular node (AV node) Impulse ends at Purkinje fibers Allow atria to contract and Result in contraction and ventricles to fill emptying of ventricles Rate 40-60 bpm Located between atria and ventricles 7 AUTONOMOUS NERVOUS SYSTEM Controls he conduction system of the heart Sympathetic: speeds the heart rate Parasympathetic: slows the heart rate Allows for appropriate changes in the cardiac output to meet demands of the body 8 CHECK ON LEARNING Which of the following is the correct impulse pattern of the cardiac conduction system? a. SA node -> Bundle of His -> AV node -> Purkinje fibers -> bundle branches b. Pacemaker -> Purkinje fibers -> AV node -> Bundle of His -> bundle branches c. SA node -> AV node -> Bundle of His -> bundle branches -> Purkinje fibers d. Pacemaker -> SA node -> Bundle of His -> AV node -> Purkinje fibers 9 3  10/20/2023 CARDIAC DYSRHYTHMIA ANALYSIS 10 ELECTROCARDIOGRAM (EKG) Recording of the electrical activity of the myocardium Determines transmission of cardiac electrical impulses Normal conduction Depolarization Electrical impulse through myocardium Recorded on EKG Repolarization Recovery from the electrical impulse During diastole when the heart is at rest 11 EKG MACHINE Recording of heart activity using electrode sensors Heart activity recorded on ECG graph paper with vertical and horizontal axis. Horizontal axis- time in seconds. 1 mm square (small box) equals 0.04 seconds A 5 mm square (large box) represents 0.20 seconds Top margin of paper 1-second intervals The vertical axis represent voltage. 1 mm grid interval represents 1 millivolt 12 4  10/20/2023 13 ASSESSMENT OF RHYTHM STRIP Three limb leads are I, II, and III Placed on arms and legs Leads are marked RA, LA, and LL Lead placement Below right and left clavicle Leg lead placed on left lower abdomen 5- lead or 12-lead 14 15 5  10/20/2023 EKG LEAD PLACEMENT 16 17 PQRST COMPLEX 18 6  10/20/2023 COMPONENTS Cardiac electrical activity represented in time intervals Wave configurations P, Q, R, S, T Waveforms positive or negative Relation to the isoelectric line P wave- atrial depolarization (SA Node) Q wave- first negative deflection >0.4 seconds (1/4 height of R wave) R wave- first positive deflection S wave- negative deflection after R wave 19 QRS COMPLEX Representation of ventricular depolarization Normal duration- 0.06-0.10 seconds Narrow QRS complex Greater than 0.10 seconds Wide complex QRS Indicates conduction delay in ventricles Causes for delay in conduction Bundle branch block Aberrancy 20 WIDE QRS COMPLEX 21 7  10/20/2023 PR INTERVAL 22 PR INTERVAL, T WAVE , ST SEGMENT PR Interval Time it takes an impulse to travel from SA node to AV node fibers Measured from beginning of P wave to beginning of QRS Normal duration: 0.12 -0.20 seconds T wave – represents ventricular repolarization ST segment- represents early repolarization of ventricular muscle 23 EKG INTERPRETATION 24 8  10/20/2023 STEPS TO INTERPRETATION Determine if heart rate is normal, fast, or slow Determine the rhythm (or regularity) Find the P waves Measure the QRS complex Find the T waves Evaluate the ST segment Measure QT interval 25 STEP 1- DETERMINE HEART RATE Three methods 1. The Six-Second Method 2. 300 Method (Large Box Method) 3. 1500 Method (Small Box Method) 26 THE SIX-SECOND METHOD Obtain six-second tracing (30 large boxes) and count R waves that appear in 6 seconds Multiply by to obtain heart rate/minute Example: If there are 8 QRS complexes, multiply QRS complexes x 10. Answer: 80 bpm 27 9  10/20/2023 THE 300 METHOD Large Box Method Count the number of boxes between two R waves Divide this number into 300 to obtain heart rate/minute Example: 4 large boxes between to consecutive R waves, 300/ 4. Answer: 75 bpm 28 THE 1500 METHOD Small Box Method Count the number of boxes between two R waves Divide this number in 1500 obtain the heart rate/minute Example: If there are 19 small boxes between to consecutive R waves, 1500/19 Answer: 79 bpm 29 DETERMINE THE RHYTHM Look at the R-R intervals Are they regular or irregular? Are the intervals between the complexes the same? 30 10  10/20/2023 STEP 2- FIND THE P WAVES What is the configuration? Are they upright and identical? Is there a P wave for every QRS complex? Is there a QRS complex for every P wave? 31 STEP 3- PR INTERVAL Measure from the beginning of the P wave to the beginning of the Q wave. Normal interval: 0.12 – 0.20 seconds Are all P-R intervals the same length? Is the relationship between the P wave and QRS complex constant? 32 STEP 4- MEASURE QRS COMPLEX Measure the complex from the beginning of the Q wave to the point that the S wave meets the isoelectric line. Normal: 0.06 – 0.10 seconds 33 11  10/20/2023 STEP 5- FIND THE T WAVES Are they positively or negatively deflected? Above or below the isoelectric line? Are they peaked? 34 STEP 6- MEASURE QT INTERVAL Normal should be ½ of R to R interval 35 ACTIVITY: INTERPRET RHYTHM STRIP 36 12  10/20/2023 COMMON DYSRHYTHMIAS 37 DYSRHYTHMIA Any cardiac rhythm that deviates from normal sinus rhythm Causes can include: Alteration in the formation or transmission of impulses from the SA node Irritability of myocardial cells that generate impulses Signs and symptoms vary depending on the type and severity Ranges from minor to life-threatening 38 SINUS TACHYCARDIA Rapid, regular rhythm Originates in SA node Heartbeat: 100 to 150 bpm or more Stimulated by sympathetic nervous system Can be gradual or abrupt Causes of rate increase: Causes Exercise Anxiety Fever Shock Medications Heart failure Caffeine 39 13  10/20/2023 CLINICAL MANIFESTATIONS Occasional palpitations or asymptomatic Vulnerable populations are those with ischemic heart disease Hypotension Angina 40 MEDICAL MANAGEMENT Directed at treating the primary cause of the tachycardia Normal rhythm not usually caused by cardiac problem Due to sympathetic response Treat underlying cause first (ex. Treat fever with antipyretic) 41 SINUS BRADYCARDIA Slow rhythm Originates in the SA Node Parasympathetic nervous system stimulation Causes include: Obstructive sleep apnea Intracranial tumors Myocardial infarction Medications Carotid sinus massage Vasovagal stimulation Endocrine disorders Hypothermia 42 14  10/20/2023 CLINICAL MANIFESTATIONS May not be manifested until heart rate falls below 60 bpm Slowed heartrate causes a decrease in cardiac output Symptoms of decreased cardiac output: Fatigue Hypotension Lightheadedness Syncope Some patients, especially athletes, may be asymptomatic 43 MEDICAL MANAGEMENT Directed at the primary cause and maintaining cardiac output Assess for hemodynamic instability related to bradycardia If symptomatic- give medications Example: atropine Atropine unsuccessful Transcutaneous pacing with medications Examples: dopamine and epinephrine Transcutaneous pacing is temporary until a permanent pacemaker can be placed Hold all medications that cause bradycardia 44 SUPRAVENTRICULAR TACHYCARDIA (SVT) The sudden onset of a rapid rhythm Originates in the atria Characterized by a pulse rate of 150 – 250 bpm Typically, not caused by heart disease Causes include: Medications Alcohol Mitral valve prolapse Sympathetic response to emotional stress 45 15  10/20/2023 CLINICAL MANIFESTATIONS The faster the tachycardia, the more symptomatic the patient may become Symptoms include: Decreased coronary artery filling Decreased cardiac output to brain and organs 46 MEDICAL MANAGEMENT Assess the patient Are they stable or unstable? If symptomatic and rate is >150 bpm Emergent cardioversion If stable Focus aimed at decreasing heart rate and eliminating underlying cause Carotid sinus pressure Medications (Example: adenosine, digoxin, beta blockers, calcium channel blockers, or amiodarone) 47 ATRIAL FLUTTER Irritable focus in the atria causes atria to fire at extremely rapid rate Characterized by rate of 250-300 bpm Distinguishing feature is “saw tooth” appearance If untreated, rapid ventricular response (RVR) Rate >100 bpm Causes Lung disease Ischemic heart disease Hyperthyroidism Hypoxemia Heart failure Alcoholism 48 16  10/20/2023 ATRIAL FIBRILLATION Multiple ectopic foci in atria cause chaotic quivering of the atria and ineffective atrial contraction The atria beat chaotically Characterized by atrial rate of 350-600 bpm Rapid ventricular response Rhythm classified as “irregularly irregular” 49 ATRIAL FIBRILLATION Most common dysrhythmia observed in clinical practice Referred to as A Fib Without help of atria, ventricles do not fill completely AV node receives hundreds of atrial impulses in an unpredictable manner Results in decreased cardiac output 50 ATTRIBUTABLE CAUSES Acute myocardial Heart failure infarction Cardiomyopathy Longstanding Congenital abnormalities hypertension Chronic obstructive Pulmonary embolism pulmonary disease Atherosclerosis Thyrotoxicosis Mitral valve disease OTC cold medications 51 17  10/20/2023 CLINICAL MANIFESTATIONS Patient may be unaware Increased ventricular response may cause Pulse deficit Palpitations Dyspnea Angina Lightheadedness Syncope Fatigue Change in LOC Pulmonary edema 52 MEDICAL MANAGEMENT Focused on treating of the irritability of the atria Slowing the ventricular response to atrial stimulation Correcting the primary cause Therapy goal is to prevent atrial thrombi Patient will be prescribed anticoagulation therapy Heparin or warfarin (Coumadin) Rivaroxaban (Xarelto) INR goal of 2-3 53 MEDICAL MANAGEMENT Pharmacological treatment to achieve cardioversion to treat ventricular rate Calcium channel blockers Beta blockers Digoxin Amiodarone If patient is unstable or unresponsive to medications Synchronized cardioversion will be performed If pharmacologic or synchronized cardioversion Patient must undergo transesophageal echocardiogram (TEE) If all other treatments fail  ablation 54 18  10/20/2023 ATRIOVENTRICULAR BLOCK (AV) Introduction to Critical Care Nursing, Chapter 8, pp. 137-140 55 ATRIOVENTRICULAR BLOCK A defect in the AV node that slows or impairs conduction Three types First degree Second degree (Type I and Type II) Third degree 56 FIRST DEGREE AV BLOCK Underlying rhythm is normal Prolonged PR interval Rate: normal P wave: present for each QRS complex PR interval: >0.20 seconds Causes include: Aging Ischemic and valvular heart disease Does not require treatment 57 19  10/20/2023 SECOND DEGREE AV BLOCK Classified as Type I and Type II Type I - Mobitz I or Wenckebach Type II – Mobitz II Rate: normal R – R interval irregular P wave: more P waves than QRS complexes PR interval: variable 58 TYPE I -WENCKEBACH Progressive lengthening of the PR interval until there a P wave without a QRS PR following dropped QRS is shorten than PR interval before the dropped beat 59 TYPE I- WENCKEBACH Causes include - Aging AV nodal blocking drugs (Example: beta blockers, calcium channel blocker, digoxin) Acute inferior or right ventricular myocardial infarction Ischemic heart disease Digitalis toxicity No treatment necessary, unless dropped beats occur frequently 60 20  10/20/2023 TYPE II- MOBITZ II OR CLASSICAL Heart rate is slower than the underlying rhythm because of dropped beats Rhythm: P waves are regular, QRS complexes are absent PR interval: usually normal and constant for underlying rhythm QRS complex: consistent in shape. May widen because of a bundle branch block 61 TYPE II- MOBITZ II OR CLASSICAL Causes include - Heart disease Increased vagal tone Conduction system disease Ablation of the AV node Inferior and right ventricular myocardial infarctions Medical Management Pacemaker may be required Atropine Transcutaneous or transvenous pacing Emergent and temporary 62 THIRD DEGREE AV BLOCK Referred to as complete heart block Rate Atrial rate – normal Ventricular rate- usually 20-40 bpm Rhythm P – P interval regular R-R interval regular There is NO relationship between P wave and QRS complexes P wave: present and consistent PR interval: unmeasurable 63 21  10/20/2023 ETIOLOGY Atria and ventricles beat independent of one another The AV node is completely blocked to sinus impulse Atria beat at one rate, ventricles at another Causes include: Ischemic heart disease Acute myocardial infarction Conduction system disease Patients are bradycardic and symptomatic Prepare for pacemaker 64 PREMATURE VENTRICULAR CONTRACTIONS (PVC) Abnormal beats that arise from the right or left ventricle Common ventricular dysrhythmia Rate: matches underlying rhythm Rhythm: interrupted by premature beat Interval measurements: No PR interval QRS complex >0.12 seconds PR interval: unmeasurable “Wide and bizarre” 65 ETIOLOGY PVCs are early beats that interrupt the underlying rhythm Occurs in ventricles Single foci produces PVC waveforms that look alike Multiple foci produce waveforms that look different May occur in a predictable pattern, in healthy people Usually, will not require treatment Caused by: Hypoxemia Ischemic heart disease Hypokalemia Hypomagnesemia Increased catecholamine levels Digitalis toxicity 66 22  10/20/2023 CLINICAL MANIFESTATIONS/ MEDICAL MANAGEMENT Patient may feel palpitations Symptoms depend on frequency and effect on the heart Patient may be asymptomatic or show signs and symptoms of decreased cardiac output Medical Management Focuses on underlying cause Many patients remail stable Symptomatic patients Treated with beta-adrenergic blockers, antianginals, and antidysrhythmic drugs. 67 VENTRICULAR TACHYCARDIA Three or more successive PVCs Rapid, life-threatening dysrhythmia Originating from a single ectopic focus in the ventricles Rate: The heart rate is 110 – 250 bpm Rhythm: Regular unless capture beats occur and momentarily interrupt the V-Tach Interval measurements: No PR interval. QRS complex is > 0.12 seconds Often wider than 0.16 seconds 68 ETIOLOGY The wave depolarization associated with V-Tach Abnormal and produces widened QRS complexes SA Node may continue to depolarize at its normal rate Causes include: Acute MI Hypoxemia Metabolic acidosis Electrolyte disturbances Toxicity to certain drugs 69 23  10/20/2023 CLINICAL MANIFESTATIONS A pulse and blood pressure will be present If cardiac output is impaired, the patient will have symptoms of low cardiac output 70 MEDICAL MANAGEMENT IV procainamide or amiodarone Lidocaine if acute myocardial ischemia or infarction is considered cause Cardioversion is used when the patient has a pulse but is hemodynamically unstable Advanced cardiac life support (ACLS) is used when the patient has no pulse 71 VENTRICULAR FIBRILLATION Ventricular musculature is quivering Produces clinical death and must be reversed immediately No cardiac output Rate: non-discernible Rhythm: non-discernible Interval measurements: there are no waveforms Shape and Sequence: the baseline is wavy and chaotic, with no PQRST complexes 72 24  10/20/2023 ETIOLOGY Chaotic rhythm characterized by a quivering of the ventricles Results in total loss of cardiac output and pulse Causes include: Ischemia from MI Valvular heart disease Electrolyte (potassium) and acid-base imbalances QT prolongation from medications like digoxin and quinidine 73 MEDICAL MANAGEMENT Providing emergency treatment, including CPR Check pulse and respirations Circulation: begin compressions Airway: open the airway Breathing: provide positive pressure ventilations Defibrillation Ideally performed within 15 – 20 seconds of onset to avoid brain damage Epinephrine: 1 mg IVP (every 3-5 min) Continue CPR Amiodarone 74 ASSESSMENT Subjective Objective Palpitations EKG monitoring Skipped beats Syncope Nausea Irregular pulse Light-headedness Tachycardia Vertigo Tachypnea Anxiety Dyspnea Fatigue Chest discomfort 75 25  10/20/2023 DIAGNOSTIC TESTS Assess if patient presentation is “normal” for this patient Example: athletes may be bradycardic EKG monitoring Telemetry Holter monitoring Cardiac catheterization 76 CHECK ON LEARNING The patient’s cardiac monitor shows a regular rhythm with a rate of 65 bpm. P waves precede each QRS complex, QRS complexes are symmetrical and regularly spaced, and a normal T wave shows repolarization. What is the nurse’s interpretation of the monitor display? a. Vital signs should be immediately assessed. b. The monitor indicates normal sinus rhythm. c. The monitor is showing a benign dysrhythmia. d. The patient should be assessed for chest pain. 77 CHECK ON LEARNING The patient who had a myocardial infarction 2 weeks ago is now having frequent episodes of ventricular tachycardia. For this patient, what is the clinical significance of the dysrhythmia? a. Warning sign for ventricular fibrillation. b. Expected finding at this stage in recovery after a MI. c. Reaction to a beta-adrenergic blocker. d. Treatment is given only for symptoms. 78 26  10/20/2023 NURSING INTERVENTIONS/ PATIENT TEACHING Take apical pulse for one full minute Assess patient’s: Anxiety Level of understanding of diagnosis, procedures, and treatments 79 PATIENT PROBLEM NURSING INTERVENTION Cardiac output, decreased, related to cardiac 1. Monitor heart rate and rhythm to ensure there is insufficiency enough supply for the demand. 2. Periodically assess and reassess tissue perfusion 3. Check skin for color, moisture, and temperature. Peripheral pulses, and urine output. 4. Administer oxygen for dyspnea, chest pain, or syncope 5. Administer anti-dysrhythmias as ordered 6. Reduce cardiac workload by placing patient on limited activities or complete bed rest 7. Elevate HOB 30-45 degrees Pain, related to ischemia 1. Administer oxygen and dysrhythmia medication as ordered 2. Teach relaxation techniques 3. Institute position change 4. Notify physician of any chest pain Coping, Ineffective related to fear of uncertainty about 1. Allow patients to verbalize their fears and disease process emotions 2. Reassure patients that they are under the constant supervision of the health care team 3. Emphasize those things the patient can do 80 PATIENT TEACHING Focus on therapeutic interventions Teach patient how to take medications Teach the patient technique for palpating and counting the radial pulse Explain the importance of avoidance of tobacco and other stimulants Instruct patient regarding energy conservation Give the patient and family an opportunity to ask questions Encourage patient to participate in a stress management class 81 27  10/20/2023 CHECK ON LEARNING Which patient problem focuses on the physiological aspects of dysrhythmias? 82 CARDIOVERSION The delivery of a shock that is synchronized with the patient’s cardiac rhythm. 83 PURPOSE AND USE To disrupt an ectopic pacemaker that is causing a dysrhythmia and allow the SA node to take control of the rhythm. Use: for tachydysrhythmias who have a pulse with symptoms related to poor perfusion Emergent in the unstable patient Scheduled in the stable patient with sedation Usually conducted in the intensive care unit (ICU) or recovery room Much lower voltage than with defibrillation Defibrillator set on “synchronize” 84 28  10/20/2023 NURSING INTERVENTIONS Before cardioversion Prepare patient emotionally and physically Hold digitalis and diuretics (if applicable) Obtain 12-lead ECG Ensure informed consent is signed Ask the patient to void Obtain IV access NPO hours before the procedure Attach patient to defibrillator monitor Select lead for observation 85 NURSING INTERVENTIONS After cardioversion Monitor vital signs frequently Cardiac monitoring Repeat 12-lead ECG 86 CHECK ON LEARNING Your patient is scheduled to undergo a cardioversion. Following delivery of the shock, the patient suddenly develops ventricular fibrillation (a life-threatening condition). What error likely caused this? 87 29  10/20/2023 CHECK ON LEARNING [True or False] The electrical shock is delivered immediately after the button is depressed during a cardioversion. 88 PACEMAKER 89 ARTIFICIAL CARDIAC PACEMAKERS Battery-operated device that initiates and controls the heart rate by delivering an impulse to the myocardium Used for patients with bradydysrhythmias, tachydysrhythmias, or AV blocks Rate responsive Pacemakers are placed either temporarily (transcutaneous or transvenous) or permanently (surgically) 90 30  10/20/2023 NURSING INTERVENTIONS After placement, closely monitor heart rate rhythm Check vital signs and LOC regularly Check insertion Immobilize affected arm for the first few hours after placement 91 PATIENT TEACHING Wear Medic-Alert bracelet Nurse should emphasize the importance of reporting adverse signs and symptoms of pacemaker malfunction How to take a radial pulse and notify physician if pulse falls below pacemaker settings Pulse should be taken at the same time every day Avoid holding electrical appliances close to the pacemaker Avoid proximity to high output generators or large magnets Move away from devices that cause the pacemaker to malfunction 92 CHECK ON LEARNING Identify three symptoms of a patient with a malfunctioning pacemaker. 93 31  10/20/2023 CHECK ON LEARNING For which dysrhythmia would a pacemaker most likely be necessary? a. Sinus tachycardia b. Premature ventricular contractions c. Third degree heart block d. Atrial fibrillation 94 CHECK ON LEARNING A patient is being discharged after receiving a permanent pacemaker. What is the best rationale to give a patient about refraining from sports such as tennis, swimming, golf, and weightlifting initially after discharge? a. “First, you have to be able to climb at least two flights of stairs.” b. “Active sports will interfere with the pacemaker’s fixed mode.” c. “These sports are too strenuous and rapidly increased your heart rate.” d. “You shouldn’t lift your arm over your head.” 95 MEDICAL MANAGEMENT Immediate CPR to prevent organ damage Prevention of severe damage to the brain, heart, liver, and kidneys as a result of anoxia Remember the CAB of CPR C- circulation A- restore airway B- restore breathing 96 32  10/20/2023 ACTIVITY #2 Interpret cardiac rhythm strips Rate: Rhythm: PR Interval: QRS complex: 97 REVIEW OF MAIN POINTS Electrical conduction of the cardiovascular system Basics of dysrhythmias analysis Interpret eight common dysrhythmias, clinical significance, and treatment Identify nursing interventions and patient teaching for a patient with a cardiac dysrhythmia Identify the purpose of a cardioversion Identify the nursing implications of a patient with a pacemaker 98 QUESTIONS? 99 33