Advanced Med-Surg High-Yield Study
Guide
Arrhythmias, ECG Interpretation, Cardioversion, Defibrillation,
Pacemakers, ICDs, and Nursing Management
Based on the provided Chapter 22 arrhythmia and conduction notes.
Big Theme
Arrhythmias are electrical problems, but nurses care because they can cause perfusion
problems. Always assess the patient, not just the monitor.
Quick Navigation
Core concepts and normal conduction
ECG components and rhythm-strip analysis
Sinus and atrial rhythm basics
Treatment decision framework
Antiarrhythmic medications
Cardioversion and defibrillation
EPS and ablation
Pacemakers and CRT
ICDs and wearable defibrillator vest
Nursing management, complications, and exam traps
1. Core Concept: What Is an Arrhythmia?
An arrhythmia, also called a dysrhythmia, is a disorder in the formation of the electrical
impulse, the conduction of the impulse, or both. It can disturb heart rate, rhythm, or both. The
ECG shows the electrical problem, but the patient shows whether the rhythm is being
tolerated.
Formation problem: the impulse starts in the wrong place, too fast, too slow, or fires early.
Conduction problem: the impulse is delayed, blocked, or travels abnormally.
Hemodynamic effect: the rhythm changes pumping ability and may cause hypotension,
dizziness, chest pain, shock, or syncope.
Priority Question
Is the patient stable or unstable? The same rhythm can require monitoring in one patient and
emergency treatment in another.
Stable vs. Unstable Rhythm Patient
Stable Unstable
Alert; BP acceptable; pulse present; no chest pain; Hypotension; chest pain; altered mental status;
Advanced Med-Surg Arrhythmias Study Guide
, syncope; severe SOB; pulmonary edema;
no severe shortness of breath; skin warm/dry cool/clammy skin; weak pulse; shock; decreased
urine output
Rapid response/code-level thinking; oxygen, IV
Usually monitor, assess cause, notify provider,
access, ECG, emergency meds, cardioversion,
labs/meds as ordered
defibrillation, pacing, or CPR depending on rhythm
2. Normal Electrical Conduction
Normal conduction follows this order: SA node -> atria -> AV node -> Bundle of His ->
right/left bundle branches -> Purkinje fibers -> ventricles.
Structure/Event Plain Meaning Why It Matters
Natural pacemaker in right If rhythm starts here, it is a sinus
SA node
atrium; normally 60-100 bpm rhythm
Atria Atria depolarize and contract first Atrial kick helps fill ventricles
Allows ventricular filling before
AV node Slows the impulse briefly
ventricular contraction
Rapidly spread impulse through Allows coordinated ventricular
Bundle branches/Purkinje fibers
ventricles contraction
Loss of atrial kick decreases
Final push of blood from atria into
Atrial kick cardiac output, especially in
ventricles
AFib/HF
Electrical vs. Mechanical Events
Electrical Event Mechanical Event Meaning
Electrical activation causes
Depolarization Systole
contraction/squeezing
Electrical reset allows
Repolarization Diastole
relaxation/filling
3. Autonomic Nervous System Effects
System Effects Clinical Meaning
Can increase arrhythmia risk by
Increases HR, AV conduction,
Sympathetic = gas pedal increasing electrical irritability
contractility, vasoconstriction, BP
and oxygen demand
Can slow rhythms; excessive vagal
Decreases HR, AV conduction, and
Parasympathetic = brake pedal stimulation may cause
atrial contraction force
bradycardia
Key Terms
Term Meaning Positive/Negative Effect
Positive = faster HR; negative =
Chronotropy Heart rate
slower HR
Conduction speed through AV Positive = faster conduction;
Dromotropy
node negative = slower conduction
Positive = stronger squeeze;
Inotropy Force of myocardial contraction
negative = weaker squeeze
Increased sympathetic triggers: exercise, anxiety, fever, pain, shock, hypovolemia,
dopamine, dobutamine, aminophylline, atropine, caffeine, nicotine, cocaine, amphetamines.
Advanced Med-Surg Arrhythmias Study Guide
Guide
Arrhythmias, ECG Interpretation, Cardioversion, Defibrillation,
Pacemakers, ICDs, and Nursing Management
Based on the provided Chapter 22 arrhythmia and conduction notes.
Big Theme
Arrhythmias are electrical problems, but nurses care because they can cause perfusion
problems. Always assess the patient, not just the monitor.
Quick Navigation
Core concepts and normal conduction
ECG components and rhythm-strip analysis
Sinus and atrial rhythm basics
Treatment decision framework
Antiarrhythmic medications
Cardioversion and defibrillation
EPS and ablation
Pacemakers and CRT
ICDs and wearable defibrillator vest
Nursing management, complications, and exam traps
1. Core Concept: What Is an Arrhythmia?
An arrhythmia, also called a dysrhythmia, is a disorder in the formation of the electrical
impulse, the conduction of the impulse, or both. It can disturb heart rate, rhythm, or both. The
ECG shows the electrical problem, but the patient shows whether the rhythm is being
tolerated.
Formation problem: the impulse starts in the wrong place, too fast, too slow, or fires early.
Conduction problem: the impulse is delayed, blocked, or travels abnormally.
Hemodynamic effect: the rhythm changes pumping ability and may cause hypotension,
dizziness, chest pain, shock, or syncope.
Priority Question
Is the patient stable or unstable? The same rhythm can require monitoring in one patient and
emergency treatment in another.
Stable vs. Unstable Rhythm Patient
Stable Unstable
Alert; BP acceptable; pulse present; no chest pain; Hypotension; chest pain; altered mental status;
Advanced Med-Surg Arrhythmias Study Guide
, syncope; severe SOB; pulmonary edema;
no severe shortness of breath; skin warm/dry cool/clammy skin; weak pulse; shock; decreased
urine output
Rapid response/code-level thinking; oxygen, IV
Usually monitor, assess cause, notify provider,
access, ECG, emergency meds, cardioversion,
labs/meds as ordered
defibrillation, pacing, or CPR depending on rhythm
2. Normal Electrical Conduction
Normal conduction follows this order: SA node -> atria -> AV node -> Bundle of His ->
right/left bundle branches -> Purkinje fibers -> ventricles.
Structure/Event Plain Meaning Why It Matters
Natural pacemaker in right If rhythm starts here, it is a sinus
SA node
atrium; normally 60-100 bpm rhythm
Atria Atria depolarize and contract first Atrial kick helps fill ventricles
Allows ventricular filling before
AV node Slows the impulse briefly
ventricular contraction
Rapidly spread impulse through Allows coordinated ventricular
Bundle branches/Purkinje fibers
ventricles contraction
Loss of atrial kick decreases
Final push of blood from atria into
Atrial kick cardiac output, especially in
ventricles
AFib/HF
Electrical vs. Mechanical Events
Electrical Event Mechanical Event Meaning
Electrical activation causes
Depolarization Systole
contraction/squeezing
Electrical reset allows
Repolarization Diastole
relaxation/filling
3. Autonomic Nervous System Effects
System Effects Clinical Meaning
Can increase arrhythmia risk by
Increases HR, AV conduction,
Sympathetic = gas pedal increasing electrical irritability
contractility, vasoconstriction, BP
and oxygen demand
Can slow rhythms; excessive vagal
Decreases HR, AV conduction, and
Parasympathetic = brake pedal stimulation may cause
atrial contraction force
bradycardia
Key Terms
Term Meaning Positive/Negative Effect
Positive = faster HR; negative =
Chronotropy Heart rate
slower HR
Conduction speed through AV Positive = faster conduction;
Dromotropy
node negative = slower conduction
Positive = stronger squeeze;
Inotropy Force of myocardial contraction
negative = weaker squeeze
Increased sympathetic triggers: exercise, anxiety, fever, pain, shock, hypovolemia,
dopamine, dobutamine, aminophylline, atropine, caffeine, nicotine, cocaine, amphetamines.
Advanced Med-Surg Arrhythmias Study Guide
