Normal Sinus Rhythm
Originates in the SA node, follows appropriate
conduction pathways.
Rhythm:
Regular
Rate:
60-100 bpm
Every P has a QRS and every QRS has a P
PRI:
0.12-0.20 seconds
QRS: 0.08 -0.12 seconds, narrow
Sinus Tachycardia
Originates in the SA node.
Rapid rhythm which occurs with
increased oxygen demand ( exercise, infection,
hypovolemia, hypoxia, MI, and to stimulant drugs).
Rhythm:
regular/fast
Rate:
> 100 bpm
Every P has a QRS and every QRS has a P
PRI:
.12 - .20 seconds
QRS:
normal
Atrial Problems
Atrial Flutter
Atrial Fibrillation
47
Atrial Flutter
Characterized by “saw tooth” atrial activity
Conduction ratio to the ventricles 2:1 – 8:1. ( usually
2:1-4:1)
Caused by a reentrant circuit located in the right atrium.
May occur in COPD, hypoxia, intrinsic cardiac disease,
valve disease, pericarditis or post operatively.
If >150 bpm, may seriously compromise cardiac output.
Treatment is rate control, cardioversion, surgical
or catheter ablation.
Rate: atrial rate 250-400 (generally 300bpm)
49
Atrial Flutter
TREATMENT
–
TREAT UNDERLYING CAUSE
–
IRRITABILITY, RAPID VENTRICULAR
RESPONSE
–
DIGOXIN SLOWS RATE BY ENHANCING AV
BLOCK
–
QUINIDINE SUPRESSES ATRIAL ECTOPIC
BEATS
–
AMIODARONE
–
CALCIUM CHANNEL &
β-
BLOCKERS
–
CONSIDER CARDIOVERSION
51
Atrial Fibrillation
Deviation from NSR
–
No organized atrial
depolarization
(contraction),
so no normal P waves
(impulses are not originating
from the sinus node).
