Arrhythmia Classification

Question 1

Types of arrhythmias

Answer 1

Sinus arrhythmias
Atrial arrhythmias
Nodal arrhythmias
Ventricular arrhythmias

Question 2

Types of arrhythmias: Tachycardia

Answer 2

Sinus tachycardia
Atrial tachycardia
Atrial fibrillation/flutter
AV Nodal Re-entry tachycardia
Wolff Parkinson White Syndrome
Ventricular tachycardia
Ventricular fibrillation

Question 3

Slow arrhythmias: Bradycardia

Answer 3

• Bradycardia
• AV Nodal block: 1st, 2nd, and 3rd degree
• Asystole

Question 4

Heart Rates in BPM

Answer 4

500: Atrial or ventricular Fibrillation
350: Atrial flutter
150-250: Ventricular or supraventricular arrhthymias
60-100: Normal
40: Moderate bradycardia
20: Severe bradycardia

Question 5

Etiology of arrhythmias: Metabolic

Answer 5

1. Ectopic conduction/early afterdepolarization
2. Ischemic tissue
3. Electrolyte abnormalities
4. Drug toxicity
5. Genetic abnormalities (QT prolongation)

Question 6

Etiology of arrhythmias: Structural

Answer 6

1. Scarring/fibrotic areas of no conduction
2. Cardiomyopathy and hypertrophy
3. Accessory pathways/block/congenital malformations

Question 7

Formation of arrhythmias: 2 main mechanisms

Answer 7

1. Disorder of impulse generation
     A: Abnormal automaticity
     B: Triggered activity, early or delayed afterdepolarizations
2. Abnormal conduction
    A. Block
    B: Re-entry

Question 8

Disorder of impulse generation: Abnormal automaticity

Answer 8

Slope of phase 4:

 - Increase in slope means increase in heart rate
 - Sympathetic activity increases heart rate
 - Cholinergic activity decreases heart rate
 - Antiarrhythmic drugs make changes on slope and change heart rate

Question 9

Disorder of impulse generation: Afterdepolarizations

Answer 9

1. EAD: Caused by opening of Na+, Ca+, and K+ channels

2. DAD: Caused by elevated systolic Ca+ ions

Question 10

Afterdepolarizations

Answer 10

Early: Occuring during phases 2 or 3
Delayed: Occuring during phase 4
Caused by: Opening of L-type calcium channel, opening of Na+ channel, closing of K+ channel. These are caused by elevated systolic Ca+ ions (Digoxin), long QT syndrome, or K+ channel blockers

Question 11

Abnormal Impulse Conduction: Block

Answer 11

• Area of tissue that does not conduct electrical impulse
• 3rd degree AV Nodal block: There is no association between Atria and Ventricles. They conduct impulses independently of each other.

Question 12

Abnormal impulse conduction: Re-entry

Answer 12

There is a block in the tissue that causes the electrical impulse to jump back and move to other pathway

Question 13

What are two ways to fix a re-entry arrhythmia?

Answer 13

1. Increase refractoriness

2. Provide a two-way block