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Nursing Care of Patients with Dysrhythmias

• Cardiac dysrhythmias are covered in Chapter 25 of "Understanding Medical-Surgical Nursing" (7th edition) by Williams & Hopper (2023).

Objectives

• How to identify normal sinus rhythm on an EKG strip
• How to identify selected dysrhythmias on cardiac monitor strips
• Common dysrhythmia signs and symptoms
• Signs and symptoms related to pulseless ventricular tachycardia, ventricular fibrillation, and asystole
• Electrical interventions to treat specific dysrhythmias
• How to provide nursing care and teaching for clients with cardiac pacemakers
• How to apply the nursing process to clients with dysrhythmias

Cardiac Conduction System

• A series of organized electrical impulses causes cardiac contractions.
• The SA node is in the right atrium and has an intrinsic rate of 60-100 beats per minute.
• The atrial bundle causes both atria to contract simultaneously.
• The AV node is located at the base of the right atrium.
• Additional components include the Bundle of HIS, right and left bundle branches, and Purkinje fibers.

Electrocardiogram

• Electrical impulses translate to a graph on an electrocardiogram.
• A 12-lead ECG is the most common type.
• 10 electrodes are used: 6 on the chest (V1-V6) and one on each arm and leg (RA, RL, LA, LL).
• Cardiac monitoring (telemetry) displays continuous rhythm, usually in one or two leads.

Components of the Cardiac Cycle

• P wave
• PR interval: From start of P wave to start of QRS
• QRS complex
• T wave
• QT interval: From start of Q to end of T
• ST segment: From end of QRS to start of T; it should begin and end on the baseline.

Isoelectric Line

• Indicates no electrical activity.
• All waveforms should begin and end on the baseline.
• Positive deflection: Impulses extend above the baseline
• Negative deflection: Impulses drop below the baseline

P Wave, PR Interval

• The P wave indicates atrial contraction.
• The PR interval is normally 0.12-0.20 seconds, It represents the time from the start of the P wave to the start of the QRS complex.

QRS

• The QRS complex is the largest waveform, usually upright, and stimulates ventricular contraction (systole).

T Wave, ST Segment, QT Interval

• The T wave indicates ventricular repolarization (diastole, relaxation).
• The ST segment should be at the baseline.
• Prolonged or shortened QT intervals can lead to cardiac arrhythmias.

ST Segment

• ST elevation indicates transmural myocardial infarction.
• ST depression indicates ischemia.

Steps for Identifying Cardiac Dysrhythmias

• Regularity
• Rate
• P waves
• PR interval
• QRS complex

Determining Regularity

• Measure the distance between two consecutive R-waves and compare it to the distance between the 2nd and 3rd R-waves.
• Intervals are considered equal if the distance doesn't vary by more than two small boxes.

Determining Rate

• Method 1: Count the number of small boxes (0.04 seconds) between two consecutive R-waves and divide into 1500.
• Method 2: Count the number of R-waves in a six-second interval (30 big boxes) and multiply by 10; this is best for irregular rhythms.

Normal Sinus Rhythm

• Features include a regular rhythm, a P wave before every QRS complex, a PR interval of 0.12-0.20 seconds, a narrow QRS complex, and a rate of 60-100 beats per minute.

Artifact

• Abnormalities on an electrocardiogram or rhythm strip not caused by cardiac conduction abnormalities.
• Possible causes include patient movement, poor contact with skin, or interference from electrical devices.
• Artifacts can make interpretation of the underlying rhythm difficult.

Dysrhythmias

• Can be sinoatrial, atrial, or ventricular in origin.

Common Signs and Symptoms of Dysrhythmias

• None
• Palpitations
• Signs of decreased cardiac output, including dizziness, syncope, weakness, fatigue, dyspnea, diaphoresis, pallor, and confusion/anxiety.

Pathophysiology

• Disturbances in SA node conduction.
• Sinus bradycardia involves delayed conduction through the SA node due to dysfunction or medications; it may be normal in well-conditioned athletes.
• Sinus tachycardia is a compensatory response to increased cardiac output or oxygen needs (e.g., exercise, fear, stress, fever, sepsis, dehydration, shock).
• Sinus arrhythmias are rarely dangerous.
• Those with respiratory, renal, or cardiac disease may require treatment.

Sinus Bradycardia

• Can be caused by age, being a well-conditioned athlete, medications (digoxin, beta-blockers, calcium channel blockers), hypothyroidism, or myocardial infarction.
• Treatment may not be needed if asymptomatic; otherwise, medications (epinephrine, vasopressin, atropine) or a pacemaker may be indicated.
• Treat symptoms and the underlying cause.

Sinus Tachycardia

• Associated with increased metabolic rate from stress, fear, anxiety, fever, or hyperthyroidism.
• Volume loss, dehydration, hemorrhage, and shock can also cause it.
• Symptoms and the underlying cause should be treated.
• Medications (adenosine, digoxin, beta-blockers), overdrive pacing, or cardioversion (SVT) may be considered.

Atrial Dysrhythmias

• With atrial fibrillation being the most common

Pathophysiology Review of Arrhythmias

• Increased irritability of cardiac cells.
• Aberrant pathways formed.
• Ectopic beats generated.
• Hypoxia can cause chaotic firing of cardiac cells.

Atrial Fibrillation

• Most common dysrhythmia in the elderly, and is often associated with smoking, hypertension, heart disease, and pulmonary embolism.

• Irregularly irregular rhythm with narrow QRS complexes and no identifiable P waves.

• Creates a risk for stroke and decreased cardiac output.

• May cause palpitations or heart failure.

• Is treated by addressing the underlying cause using medications (beta-blockers, calcium channel blockers, digoxin), cardioversion, or anticoagulants.

Ventricular Dysrhythmias

• Typically have wide QRS complexes.
• Originate in the ventricles.
• They are more likely to be fatal.

Signs and Symptoms of Ventricular Dysrhythmias that are Severe

• None sometimes
• signs of decreased cardiac output
• Ventricular fibrillation, pulseless ventricular tachycardia, and asystole manifest as unresponsiveness, pulselessness, absence of blood pressure, absence of respirations, and fixed, dilated pupils.

Premature Ventricular Contractions (PVCs)

• Can be caused by caffeine, alcohol, anxiety, cardiomyopathy, myocardial infarction, or hypokalemia.
• Treat underlying cause, medications like amiodarone, or beta-blockers if warranted

Multi-focal PVCs

Ventricular Tachycardia

• Is associated with myocardial infarction, cardiac irritability, hypokalemia, respiratory acidosis, and digoxin toxicity.
• The underlying cause is treated with medications (amiodarone, magnesium).
• With a pulse, cardioversion is used,.
• Pulseless V-Tach is treated with CPR and defibrillation.

Ventricular Fibrillation

• Associated with hyperkalemia, hypomagnesemia, CAD, and MI.
• ALWAYS PULSELESS
• Treat with epinephrine, CPR, and defibrillation

Asystole

• Treat with CPR and Epinephrine

Medications to Control Dysrhythmias

• Anticoagulants like warfarin, apixaban, dabigatran, or rivaroxaban are used to prevent stroke in atrial fibrillation.
• Antidysrhythmics include adenosine and amiodarone.
• Other medications used are anticholinergics (atropine), cardiac glycosides (digoxin), beta-blockers (metoprolol, atenolol), and calcium channel blockers (diltiazem).
• Vasopressors such as epinephrine and norepinephrine may also be used.

Nursing Diagnosis: Decreased Cardiac Output

• Data collection involves assessing apical pulse, blood pressure, mental status, lung sounds, and urine output.
• Interventions should include administering antiarrhythmics as prescribed, monitoring geriatric patients closely for adverse effects, and ensuring assistance with ADLs as needed, avoiding overexertion.
• Evaluation focuses on stable vital signs, the ability to complete ADLs without dyspnea, clear lung sounds, and a minimum urine output of 30 mL/hour, with no change in mental status.

Electrical Management of Dysrhythmias

• Procedures include pacemakers, cardioversion, defibrillation, and implanted cardioverter defibrillators.

Permanent Pacemakers

• Indications include persistent symptomatic bradycardia and 3rd-degree heart block.
• Pacemakers pace the atria and/or ventricles and deliver electrical impulses directly to heart muscle.
• Activity-responsive pacemakers deliver variable rates of impulses to allow for increased heart rate in response to increased cardiac output.

Nursing Care of the Patient with a Pacemaker

• Monitor heart rate and rhythm.
• Monitor for signs of decreased cardiac output, which could indicate pacemaker malfunction and require notifying the provider immediately.
• Monitor the incision for signs of healing or infection.

Patient Education Priorities for Pacemakers

• Incision care, signs of infection
• Rationale is that infection can be prevented with proper aseptic technique
• Activity restrictions: Avoid raising the arm on the pacemaker side above the head, driving, returning to work, and lifting until approved by a provider
• Help prevent complications related to pacer wire displacement while healing.
• Devices: Most grounded appliances are safe to use, but caution with metal detectors and MP3 player headphones.
• MRIs are contraindicated unless the pacemaker is non-ferrous.
• Alerts patient to possible pacemaker malfunction. -Carry cell phones on the opposite side of the pacer. -Carry a pacemaker ID card. -Keep scheduled appointments for pacemaker checks to prevent potential complications.

Cardioversion

• Indicated for symptomatic rapid dysrhythmias with a pulse.
• Requires patient preparation with consent and moderate sedation.
• Involves monitoring airway, SpO2, vital signs, heart rhythm, and skin for burns, and assessing for respiratory problems.

Defibrillation

• Used for pulseless patients with a rhythm (not for asystole), including pulseless ventricular tachycardia and ventricular fibrillation.
• Safety concerns include the risk of shock to staff and patient burns.
• Post defibrillation care focus on monitoring rate, rhythm, vital signs, and transferring the patient to the ICU.

Dysrhythmia Home Health Priorities

• Avoid straining; use laxatives as prescribed.
• Pacemakers require loose-fitting tops.
• Refill medications before major holidays or vacations.

Additional Patient Education Priorities

• For medications, educate on how to take a radial pulse, for beta-blockers, digoxin, and pacemakers, also the patient should hold the dose is bradycardia occurs.

Patient Education on Anticoagulants and Digoxin

• Anticoagulants: Provide education on signs of abnormal bleeding, manage dietary restrictions, and the importance of routine lab monitoring. The rationale: Anticoagulants can cause bleeding requiring consistent amounts of vitamin K, warfarin, heparin require routine lab monitoring to maintain therapeutic levels
• Digoxin: Check radial pulse, hold if below 60 and notify HCP, Report signs of dizziness, chest pain, syncope (decreased cardiac output), report muscle weakness (hypokalemia, increases risk of Digoxin toxicity), stay hydrated (dehydration increases risk of Digoxin toxicity), and report Anorexia, Nausea, Visual Changes (Signs of Digoxin Toxicity)
• Patients should learn CPR and have emergency phone numbers readily available for potentially lethal rhythm problems, and the need for rapid intervention.

Review: Key Areas in Nursing Care of Patients with Dysrhythmias

• EKG components
• How to recognize normal sinus rhythm
• How to manage dysrhythmias such as sinus bradycardia, sinus tachycardia, atrial fibrillation, PVCs, ventricular tachycardia, and ventricular fibrillation
• Electrical management including permanent pacemakers, cardioversion, and defibrillation
• Nursing process and patient education