Unit 2: Cardiac Dysrhythmias Flashcards
Dysrhythmias
disruptions in the cardiac conduction pathway
-disorders of the electrical impulse conduction within the heart
Symptoms of Cardiac Instability
- Palpitations (fast fluttering or beating in the chest or skipping beats)
- Hypotension
- Diaphoresis
- Shortness of breath (SOB)
- Syncope (fainting)
- Lightheadedness
- Weakness & Fatigue
- Dizziness
- Anxiety
Risk Factors for Developing a Dysrhythmia
- Age
- MI
- HTN
- Heart valve disease
- Heart failure (HF)
- Cardiomyopathy (CM)
- Infections
- Diabetes mellitus
- Sleep apnea
- Heart surgery (and procedures)
- Electrolyte disturbances
- Recreational drug use
- Drug toxicities (digoxin toxicity)
Older Adults and Cardiac Instability
older adults have fewer pacemaker cells in the SA node
-there may be fat deposits around SA node causing a delay in the propagation of the action potential
Usual Treatment Pathway
- Non-invasive/ non-pharmacological
- vasovagal maneuvers (cough, bear down) - Pharmacology
- Adenosine, Diltiazem, Atropine - Electricity
- cardioversion, defibrillation, pacing
Cardioversion
synchronized cardioversion
-controlled electrical discharge of energy at the peak of the R wave
-indicated for symptomatic tachy dysrythmias w/ a pulse (SVT, AF w/ RVR, AFL with RVR, VT w/ a pulse)
>Pulse
-SVT, A fib/flutter, VT
-start low and increase 50 to 200 Joules
-patient awake; consider sedation
Things to Consider with Cardioversion
- considered for AF after anticoagulation is attained
- the atrium is evaluated for presence of clots by esophageal echocardiogram (TEE) prior to cardioversion d/t risk of embolic events
- if pt symptomatic (hypotensive, SOB, pain), urgent cardioversion may be required before anticoagulation is attained
- IV heparin ASAP w/ loading dose before procedure
- once stable, considerations include deciding on long-term rhythm or rate control w/ digoxin, beta blockers, calcium channel blockers, or antiarrhythmic meds
Defibrillation
- no pulse
- for VT, Vfib
- joules always 200 J
- emergency, no cardiac output
Medications
> HR too fast
- Adenosine
- Diltiazem
- Digoxin
- Amiodarone
- Metoprolol
> HR to Slow
-Atropine
> Anticoagulant
- Heparin
- Warfarin
> No HR/CPR
-epinephrine
Medications for a HR that is too fast
- Adenosine
- Diltiazem
- Digoxin
- Amiodarone
- Metoprolol
Medications for a HR too Slow
Atropine
Anticoagulants
- Heparin
- Warfarin
Medications for no HR/CPR
Epinephrine
Sinus Dysrhythmias
- Sinus Bradycardia (SB)
- Sinus Tachycardia (ST)
Sinus Bradycardia
HR <60
-a regular rhythm that has the same characteristics of normal sinus rhythm (NSR) except the HR is less than 60 bpm
-Causes:
-hypoxia and/or hypothermia
-can occur during sleep or may be a normal rate in well trained athletes
-may be normal in a non-symptomatic pt; may just require observation
>important to determine if the patient is symptomatic (syncope, chest pain, hypotension, SOB, or diaphoresis) while bradycardic; require tx
Treatment for Symptomatic Sinus Bradycardia (SB)
atropine 0.5 mg IV push
Atropine Sulfate
anticholinergic
- increases SA node stimulus and increases conduction through the AV node
- use cautiously with MI patients
Asymptomatic Sinus Bradycardia (SB)
>Symptoms: None >Medical: -assess and treat the causes as necessary (hypoxia, ischemia, electrolyte imbalance, medication toxicities [digoxin, calcium channel blocker overdose]) >Nursing: notify provider -assess for level of consciousness (LOC) -assess palpable pulses -assess BP -obtain 12-lead ECG
Symptomatic Sinus Bradycardia (SB)
> Symptoms:
-hypotension, dizziness, lightheadedness, fainting, SOB, sweating
> Medical:
- oxygen
- atropine IVP
- pacing
- treat causes: hypoxia, ischemia, electrolyte imbalances, medication toxicities
> Nursing:
- 02 per order
- assess patient (initially + more frequently) for LOC, palpable pulses, BP, and HR
- contact authorized prescriber or medical emergency team
- obtain a 12-lead ECG
- ensure IV access is available and patent
- administer medications as ordered
- prepare for transcutaneous pacing/cardioversion (if ordered)
Sinus Tachycardia (ST)
HR > 100 bpm
-regular rhythm that has the same characteristics a normal sinus rhythm (NSR) except the HR is greater than 100 bpm
>Causes: fever, anemia, hypovolemia, hypotension, pulmonary embolism (PE), myocardial infarction (MI)
>Treatment: based on symptoms and causes
-Medications: Atenolol (Tenormin), Metoprolol (Lopressor), Carvedilol (Coreg), Sotalol (Betapace), Digoxin (Lanoxin)
Medications: Beta Blockers
> Atenolol (Tenormin)
Metoprolol (Lopressor)
Carvedilol (Coreg)
Sotalol (Betapace)
-slow down heart rate
-decreases cardiac workload and oxygen demand
-use cautiously in patient w/ heart failure and asthma
Medications: Digoxin (Lanoxin)
cardiac glycoside
- slows conduction through the AV node
- improves cardiac contractility
- monitor digoxin levels and renal function
- use cautiously in combo w/ amiodarone
Asymptomatic Sinus Tachycardia (ST)
> Symptoms: None
> Medical: depends on rate and cause of ST
- HR less than 150 bpm–> observe for signs of decompensation
- treat causes: infection, fever, hypovolemia, hypoxia, ischemia, electrolyte imbalance, stimulants
- HR greater than 150 bpm (pt can decompensate quickly) consider beta blockers to slow down HR
> Nursing: notify provider
- assess for LOC
- assess for palpable pulses
- assess BP
- obtain a 12-lead ECG
Symptomatic Sinus Tachycardia
> Symptoms:
-hypotension, dizziness, lightheadedness, fainting, SOB, sweating/diaphoresis, anxiety, palpitations
Medical:
- vagal maneuvers (carotid massage)
- beta blockers
- treat causes: hypoxia, ischemia, electrolyte imbalances, medication toxicities, stimulants
> Nursing:
- give O2 per order
- assess patient initially and more frequently for LOC, palpable pulses, BP, and HR
- contact authorized prescriber or medical emergency team
- obtain a 12-lead ECG
- ensure IV access is available and patent
- administer medications as ordered
- prepare for transcutaneous pacing/cardioversion if ordered
- stay w/ patient
Nursing Interventions for ALL Asymptomatic Sinus Dysrhythmias
- Notify Provider
- Assess patient for level of consciousness (LOC)
- Assess for palpable pulses
- Assess blood pressure (BP)
- Obtain a 12-lead ECG
- Educate about S/S that can occur
- Discuss S/S that warrant the patient to contact primary care provider or calling 911 for help
Nursing Interventions for ALL Symptomatic Sinus Dysrhythmias
-Give O2 per order
-Assess patient (initially + more frequently) for LOC, palpable pulses, BP, and HR
-Contact authorized prescriber or medical team
-Obtain 12-lead ECG
-Ensure IV access available as ordered
-Administer medications as ordered
-Prepare for transcutaneous pacing/cardioversion (if ordered):
>place defibrillation/pacing pads in an anterior/posterior approach
>anticipate administration of sedative (midazolam (versed)) prior to procedure if stable BP
-Stay w/ patient until stable or care is transferred to another provider
> Education:
- Medication: atropine
- Intervention: 12-lead ECG, Pacing
-after stabilization, a basic debriefing should occur w/ pt/family to allow for questions that could not be asked during emergency
Cardiac Dysrhythmias: Atrial Dysrhythmias
caused by pacemaker cells firing not from the SA node but from somewhere else within the atria
- Premature atrial contractions (PACs)
- Atrial Fibrillation (AF)
- Atrial Flutter (AFL)
- Supraventricular Tachycardia (SVT)
Premature Atrial Contractions (PAC)
-non-life threatening
-can be seen in normal sinus rhythm (NSR)
-a pacemaker cell close to the SA node fires earlier than expected
-an irregular rhythm d/t early impulse or beat
-the PAC has a pause at the end of the complex (compensatory pause) allowing the conduction system to reset and resume the regular rhythm
-P wave present
>causes: hypoxia, excessive stimulant ingestion (caffeine), infections, digoxin toxicity, and coronary artery disease
>Treatment:
-monitor frequency and eliminate the cause
