Categories of Arrhythmias

Overview

• Arrhythmias are divided into two main categories: ventricular and supraventricular.
  • Ventricular Arrhythmias: Occur in the ventricles (lower heart chambers).
  • Supraventricular Arrhythmias: Occur above the ventricles, often in the atria (upper heart chambers).
• Arrhythmias can result in heartbeats that are too slow (bradycardia) or too fast (tachycardia).

Bradycardia

• Defined as a slow heart rate (<60 beats/minute).
• Causes:
  • Electrical impulse issues in the sinoatrial node (SA node) or pathway to ventricles.
  • Common in elderly but can affect any age.
  • Potential causes include heart disease, aging, congenital defects, or side effects of medication.

Tachycardia

• Defined as a fast heart rate (>100 beats/minute).
• Types:
  • Ventricular Tachycardia: Originates in the ventricles.
  • Supraventricular Tachycardia (SVT): Originates above the ventricles.

Ventricular Arrhythmias

Ventricular Tachycardia

• SA node loses control; ventricles beat irregularly.
• Symptoms: Shortness of breath, dizziness, fainting.

Ventricular Fibrillation

• Most serious; chaotic heartbeat, up to 300 beats/minute.
• Requires immediate medical attention (CPR, defibrillation).
• High risk for individuals with heart disease.

Premature Ventricular Contractions (PVCs)

• Ventricles contract prematurely.
• Generally not serious but can indicate more severe problems.
• Can be triggered by caffeine or cold medicines.

Supraventricular Arrhythmias

• Occur above the ventricles (atria or atrial pathways).
• Often less serious than ventricular arrhythmias.
• Can be caused by tobacco, caffeine, alcohol, or medications.

Supraventricular Tachycardia (SVT) / Paroxysmal Supraventricular Tachycardia (PSVT)

• Rapid, regular heart rate (150-250 beats/minute).
• More common in children, women, and people under stress.

Atrial Fibrillation

• Fast, irregular heartbeat; main cause of stroke.
• Blood clots may form; often requires antiplatelet therapy to prevent stroke.

Wolff-Parkinson-White Syndrome

• Extra muscle pathways cause rapid heartbeat.
• May lead to PSVT.

Atrial Flutter

• Rapid atrial beating causes inefficient ventricular contraction.

Premature Supraventricular Contractions (PACs)

• Atria contract prematurely, causing out-of-sequence beats.

Postural Orthostatic Tachycardia Syndrome (POTS)

• Difficulty standing due to poor blood vessel response.
• Symptoms: Fatigue, lightheadedness, headache, fainting.

Heart Block

• Disruption in electrical signal transmission from SA node.
• First-degree: Slow signal through AV node.
• Second-degree: Delayed ventricular beat.
• Third-degree: No signal to ventricles; requires ventricular backup.
• Can be caused by aging, heart disease, or amyloidosis.

Visual and Additional Information

• Multiple educational links and resources are available for further study and professional education in cardiovascular health.