Dysrhythmias: Overview

Nursing Knowledge

Dysrhythmias: Overview

Dysrhythmias (also: arrhythmias) refer to abnormal heart rhythms resulting from irregularities in the electrical conduction system of the heart. Ranging from benign to life-threatening, these irregularities can manifest as tachycardias, bradycardias, or more complex rhythm disturbances. In clinical nursing practice, key tasks are monitoring cardiac rhythms, recognizing and categorizing dysrhythmias, administering prescribed treatments, and educating patients on potential triggers and symptom awareness.
Last updated: December 4, 2023

Table of contents

What does a normal sinus rhythm look like? 

In a normal sinus rhythm, an electrical impulse originates from the SA node in the right atrium and travels to the ventricles via the AV node and His-Purkinje system, producing a regular rhythm and heart rate between 60–100 beats per minute.

What is dysrhythmia?

Dysrhythmia, or arrhythmia, is an abnormal or irregular heart rhythm resulting from disruptions in the heart’s electrical conduction system.

How are dysrhythmias detected? 

Electrocardiograms (ECG/EKG) and telemetry are commonly used for continuous monitoring of heart rhythms.

Early detection of dysrhythmias can prevent complications, such as heart failure, stroke, or sudden cardiac death.

Common ventricular dysrhythmias 

Overview of common ventricular dysrhythmias, cardiac conduction patterns, and associated ekg changes

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Overview of common ventricular dysrhythmias, cardiac conduction patterns, and associated ECG changes

Premature ventricular complexes (PVC)

  • Electrical signal originates in the Purkinje fibers of the ventricles, causing the heart to beat too soon
  • May occur in isolation or in a repeated pattern
  • Experienced by most clients as palpitations
  • Usually benign and does not require treatment

Ventricular tachycardia (V-Tach)

  • Rapid heart beat arising from ectopic foci in the ventricles
  • Often associated with presence of scar tissue caused by ischemic
  • heart disease
  • If sustained, the heart is unable to effectively pump blood
  • May lead to hemodynamic instability and death if immediate lifesaving measures are not initiated.

Torsades de Pointes

  • A polymorphic form of ventricular tachycardia
  • Characterized by oscillatory changes in amplitude of QRS complexes around the isoelectric line on ECG/EKG
  • Results from congenital or acquired QTc prolongation
  • Torsades may resolve spontaneously or may degenerate into ventricular fibrillation. May respond to Mg infusion

Ventricular fibrillation (V-Fib)

  • Irregular electrical activity originating from multiple sites within the ventricles
  • Usually associated with underlying structural heart disease
  • The ventricles quiver instead of pumping blood, which decreases cardiac output and can be fatal within minutes without intervention. 
  • Present in 70% of sudden cardiac deaths

Common atrial dysrhythmias

Premature atrial complexes (PACs)

  • Electrical signal originates from ectopic foci within the atria, causing the heart to beat too soon.
  • The SA node usually resumes pacemaking after the ectopic beat, returning to NSR.
  • Usually intermittent and harmless

Paroxysmal supraventricular tachycardia (PSVT)

  • Electrical signal originating at or above the AV node produces abnormally fast heart rate with regular rhythm
  • Incomplete ventricular filling causes symptoms such as light-headedness, dyspnea, and chest discomfort
  • Usually intermittent
  • May resolve spontaneously or require treatment

Atrial flutter

  • Electrical signal originates from ectopic foci in the atria and travels through a reentry pathway, causing the atria to beat at a rate 3–4 times that of the ventricles.
  • On ECG, atrial flutter is recognized via a characteristic “saw tooth” pattern.
  • Puts clients at risk for blood clots and stroke
  • Must be treated

Atrial fibrillation (A-fib)

  • Multiple ectopic foci in the atria fire rapidly, producing a fast, uncoordinated atrial rhythm with irregular ventricular response.
  • Insufficient ventricular filling can cause symptoms such as fatigue, light-headedness, SOB, and chest discomfort.
  • Turbulent flow of blood through the atria puts clients at risk for blood clots and stroke.
  • Must be treated 

Treatment of atrial dysrhythmias

Atrial dysrhythmias are usually benign and can be controlled by avoiding triggers such as stimulant use and stress. If they are persistent or symptomatic, beta blockers are the first-line medication therapy. In cases refractory (unmanageable) to medication therapy and those associated with cardiomyopathy, heart failure, or conversion to A-Fib, options include atrial pacing and catheter ablation.  

Overview of acute and long term treatment options for atrial dysrhythmias

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Overview of acute and long-term treatment options for atrial dysrhythmias

Acute management of atrial fibrillation and atrial flutter

Assess hemodynamics: 

  • If stable: 
    • Rate control (beta blockers, calcium channel blockers, digoxin) 
    • Rhythm control (amiodarone, class IA, class IC)
    • Anticoagulation (based on stroke risk stratification using a scoring system such as CHADS2-Vasc) 
  • If unstable: 
    • Cardioversion
    • Anticoagulation for stroke prevention 

Long-term treatment options for atrial fibrillation and atrial flutter 

  • Pharmacologic rate/rhythm control
  • Non-urgent electrical cardioversion
  • Catheter ablation
  • Left atrial appendage occlusion
  • Pacemaker placement
  • Anticoagulation

Acute management of PSVT

Assess hemodynamics: 

  • If stable: 
    • Attempt valsalva maneuver
    • If SVT persists, adenosine rapid IV push (momentarily stops heart and may allow it to restart in normal sinus rhythm) 
  • If unstable: cardioversion

Long-term treatment options for PSVT 

  • Maintenance medications: beta blockers, calcium channel blockers
  • Override pacing: pacing heart at faster rate than native rhythm may help discontinue SVT
  • Catheter ablation

Treatment of ventricular dysrhythmias


Dysrhythmias: Overview

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Nursing Cheat Sheet

Overview of common atrial dysrhythmias, cardiac conduction patterns, and associated ECG findings

Master the topic with a unique study combination of a concise summary paired with video lectures. 

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