Cardiac Rhythm Flashcards
1
Q
autonomic NS controls
A
- rate of impulse
- speed of conduction
- strength of contraction
2
Q
cardiac conduction system
A
- SA node —> AV node —> Bundle of HIS —> Lt/Rt bundle branches —> purkinje fibres
3
Q
sinus node
A
- primary pacemaker
- 60-100 bpm
4
Q
av junction
A
- 40-60 bpm
5
Q
purkinje fibres
A
- <40 bpm
6
Q
depolarization
A
- Cells increase permeability
- Na+ floods into cells
- inside + compared to outside
7
Q
repolarization
A
- slower movement of ions across membrane returns cell to polarized state
8
Q
P wave
A
- atrial contraction (1st 1/2 Rt 2nd 1/2 Lt)
9
Q
Q wave
A
- initial phase of depolarization
10
Q
R wave
A
- depolarization of main mass of ventricles
11
Q
S wave
A
- depolarization at base of heart (purkinje)
12
Q
QRS complex
A
- combo or Q R S
- ventricular depolarization
- 0.04-0.10 seconds
13
Q
T wave
A
- ventricular repolarization
14
Q
PR interval
A
- start of atrial depol to start of ventricular depolarization
- delay at AV for filling
- 0.12-0.20 seconds
15
Q
QT interval
A
- start of ventricular depol to end of repol
