EKG & Cardiac Arrhythmias Flashcards Preview

Term 5 - PathoPhysio > EKG & Cardiac Arrhythmias > Flashcards

Flashcards in EKG & Cardiac Arrhythmias Deck (13):
1

Bradyarrhythmias caused by

  • Sinus node disease,
  • second- and third-degree heart block and
  • bradycardia associated with pacemaker malfunction

2

  • Tachyarrhythmias caused by

  • Ventricular tachycardia,
  • torsades de pointes,
  • Ventricular fibrillation 
  • supraventricular tachycardia

3

Q image thumb

4

Q image thumb

5

P-R Interval

How many small blocks?

  • P-R Interval - Normal (<5 small squares. Anything above this would be 1st degree block)

6

Reduced sinus node automaticity occurs in following conditions:

  • Sleep,
  • carotid sinus massage,
  • Age,
  • Hypothyroidism 
  • drugs (betablockers, calcium channel blockers)

7

  • Effect of stimulation of Vagus (parasympathetic) nerve on heart:
    • On SA node:
    • Mechanism:

  • On SA node: Decreases heart rate
  • Known as negative chronotropic effect
  • Mechanism:
    • ACh binds with M2 receptors in SAN;
    • Decrease in rate of rise of phase 4 and hyperpolarization of resting membrane potential lead to slow heart rate

A image thumb
8

Where can a Conduction block occur? What are the causes?

  • The AV node and His bundle are the most vulnerable sites for blocked conduction between the atria and ventricles
  • Atrioventricular block can occur:
    • Increasing age
    • Increased vagal input
    • Congenital disorders: eg., muscular dystrophy and tuberous sclerosis
    • Acquired disorders: eg., sarcoidosis, gout, Lyme disease, SLE, ankylosing spondylitis, and coronary artery disease

9

Q image thumb

10

Q image thumb

11

Q image thumb

12

Q image thumb

13

Q image thumb