Dysrhythmias for Certified Emergency Nursing (CEN)
Included In This Lesson
Study Tools For Dysrhythmias for Certified Emergency Nursing (CEN)
Outline
Dysrhythmias
Dysrhythmia Types:
- Bradycardia
- Tachycardia
- Supraventricular arrhythmias
- Ventricular arrhythmias
- Heart block
Brady-
impaired or delayed electrical impulse (SA node or CNS activation); <60bpm
100bpm (unstable >150bpm)
- Coronary artery disease
- Aging
- Respiratory (pediatrics)
- Cardiac defects
- Drugs (beta/calcium channel blockers, digoxin, clonidine)
Causes:
- Coronary artery disease
- Aging
- Respiratory (pediatrics)
- Cardiac defects
- Drugs (beta/calcium channel blockers, digoxin, clonidine)
Presentation:
- Hypotensive
- Altered mental status
- Shock
- Chest pain
- Acute heart failure
Interventions:
- Fix cause
- Asymptomatic – observation
- Stable – Atropine, IV fluids
- Unstable – dopamine/epinephrine infusion, transcutaneous pacing
Tachy-
100bpm (unstable >150bpm)
Causes:
- Acute pain, fever, activity
- Coronary artery disease
- Cardiac defects
- Electrolyte imbalances
- Excessive drug use/overdose
Presentation:
- Anxiety, diaphoresis
- Palpitations, chest discomfort § Shortness of breath
- Dizziness, syncope
- Hypotension, shock
- Loss of vital signs
- Mental status changes
Interventions:
- Fix cause
- Stable – amiodarone
- Unstable
- Cardioversion (sedation)
- Regular – 50-100j biphasic
- Irregular – 120-200j biphasic
- Cardioversion (sedation)
- Pulseless – defib, CPR, epi q3-5 minutes, amiodarone
- Cardiac workup, electrophysiology consult, cath lab, surgery (cardioverter defibrillator, pacemaker)
Supraventricular-
An abnormally fast heart rhythm due to improper electrical activity in the upper part of the heart.
- Originate in atria
- Premature atrial contractions (PACs)
- Paroxysmal supraventricular tachycardia (PSVT)
- Wolff-Parkinson-White
- Fast heart rate because of extra (abnormal) pathway between the atria and ventricles
- Presence of delta-wave
- Atrial fibrillation (quivering)
- Lack of coordinated atrial activity
- Rapid ventricular response (RVR) – ventricular rate above 100bpm
- Atrial flutter
- One or more rapid circuits in the atrium
- organized and regular rhythm
- Sawtooth
Causes:
- Conduction abnormalities
- Coronary artery disease
- Cardiac defects
- Aging
- Excessive drug use
Presentation:
- 100–250 beats/min
- Normotensive, hypotensive, or hypertensive
- Shortness of breath, dyspnea
- Palpitations, chest tightness
- Mental status changes
Interventions:
- Stable – vagal maneuvers, pharmacologic cardioversion
- Unstable – synchronized cardioversion
- 50-200 J biphasic
- Amiodarone
Ventricular arrhythmias-
Abnormal rapid heart rhythms that originate in the lower chambers of the heart (the ventricles)
- Electrical impulses originate in ventricles (SA node failure, ventricle-generated impulse)
- Premature ventricular contraction (PVC)
- “Skipped” heartbeat
- >3 PVCs in a row = VT
- Ventricular tachycardia (VT)
- With pulse or pulseless
- Torsades de pointes
- Polymorphic VT
- Variable QRS amplitude
- Ventricular fibrillation (VF) (quivering)
- Always pulseless
- No blood ejection from chambers
Causes:
- Blunt trauma
- Underlying conditions (e.g., prolonged QT syndrome)
- Diseased heart (e.g., heart failure, cardiomegaly, cardiac hypertrophy)
- Severely hypoxic myocardium
- Torsades is common in heavy ETOH users (they need MgSO4)
- Electrolyte disturbances (e.g., magnesium, potassium)
Presentation:
- Heart rate: 150–300 beats/min
- Palpitations, chest discomfort
- Syncope
- Dyspnea
- Hypotension
- Loss of vital signs
Interventions:
- Pulse – cardioversion, magnesium (torsades de pointes)
- Pulseless – defib, CPR, epinephrine
- Treat underlying cause
Heart Block: Atrioventricular Block (AVB)-
A type of heart block that occurs when the electrical signal traveling from the atria, or the upper chambers of the heart, to ventricles, or the lower chambers of the heart, is impaired.
- First degree – benign, long PR-interval
- Second degree type I (Wenckebach) – gradual prolonging PR-interval then drop (longer, longer, longer, drop; now you have a wenckebach)
- Second degree type II – consistent PR-interval before blocked P wave
- Third degree – no coordination between atria and ventricle
- P-P waves equal, QRS-QRS waves equal
Causes:
- Aging
- Coronary artery disease
- Drug overdose
Interventions:
- Atropine for low degree
- Transcutaneous pacing for high degree
- Treat underlying cause
Linchpins: (Key Points)
Electrical malfunction of the heart
- Bradycardia – slow
- Tachycardia – fast
- Supraventricular arrhythmias – up
- Ventricular arrhythmias – down
- Heart block – delayed/blocked
Transcript
For more great CEN prep, got to the link below to purchase the “Emergency Nursing Examination Review” book by Dr. Laura Gasparis Vonfrolio RN, PHD
https://greatnurses.com/
References:
- Nelson, N. (2017). Cardiovascular Emergencies. In CEN Online Review. Emergency Nurses Association.