Download Sinus Rhythm

Cardiac Arrhythmias
Sinus Rhythm
Bradyarrhythmias
Sinus Bradycardia
Sinus Pause




Characteristics
>60bpm
P-wave in front of QRS
QRS is narrow
Rhythm is regular






Slow heart beat (<60bpm)
Normal rhythm, but slow
P wave is present
QRS is narrow
SA node stops working
Pause in heart beat for 6-8s
AV Block


PR > 200ms (1 small box)
Every impulse gets through, but
is delayed
2nd degree

P waves with no QRS complex
afterwards
Some impulses get through, but
not all



1 small box = 200ms
5 small boxes = 1s
1 heart beat/5 boxes  60bpm
SSS = sick sinus syndrome
QRS is normal because it’s an
“ESCAPE” rhythm
No relationship between P-waves
and QRS
Premature beats
Atrial premature contraction
Notes
Lead II has largest P-waves (check
first)
(-)  R arm
(+)  L leg
Due to fibrosis
3 types: 1st, 2nd, and 3rd degree
1st degree
3rd degree
Example
Extra heart beats
Usually asymptomatic


QRS is normal
P-wave is present but looks
different on the premature beat
1
Cardiac Arrhythmias
AV Nodal premature
contraction = junctional


Premature ventricular
contraction



Supraventricular
Tachycardias
Sinus tachycardia
No P-wave before premature
beat b/c originates in AV node,
not atria
QRS is normal
Every other beat is abnormal
(ventricular bigemini)
One QRS complex and P-wave
are normal
Next QRS is wide and T-wave is
inverted (-)  repolarization is
abnormal



>100bpm
Normal P-wave
Narrow QRS
1 HB/2 sm boxes = 150bpm
Atrial tachycardia


P-wave is inverted (-)
2 P-waves per every QRS
complex
AV node = natural break for heart
beat
-blockers = slow down AV node
(HR)
AV nodal Reentrant
Tachycardia

No P-wave b/c it’s within QRS
complex
QRS is narrow, looks normal but
is faster
Regular rhythm


2
Cardiac Arrhythmias
Preexcitation: Wolfe
Parkinson White Syndrome

Slurred upslope on QRS and
wider complex
PR is shorter
-wave (pts. prone to SVTs)
Tachycardia path: AV node 
accessory pathway  atrium (wave disappears, but will return
once HR)
Congenital extra connection b/w
atrium and ventricle
Part of myocardium activates early
Intermittent -wave:

QRS is narrow
1:1 relationship b/w P-wave and
QRS
Can see P-wave before QRS
Different from AV nodal reentrant
tachycardia b/c there P-wave is
buried in QRS complex (can’t be
seen)
Atrial Flutter





Starts in RA and is CCW
Regular and reproducible
QRS is narrow
See (-) complexes
Saw tooth pattern
Atrial Fibrillation


Disorganized rhythm
Pulse is irregularly
irregular/irregular rhythm
QRS is narrow
No P-wave



SVT with short RP (refractory
period)




Ventricular tachyarrhythmia







Wavelet hypothesis  multiple
circuits start and extinguish
continually
Occur in bottom chambers
>3 PVC in a row  V-tach
Nonsustained  stops after a
certain time period
No P-waves
Repolarization is abnormal
QRS complexes are wider
More QRS than P-waves
3
Cardiac Arrhythmias
Torsades de Pointes
(polymorphic V-tach)


Long QT interval
QRS complexes are all over the
place  look abnormal
Ventricular Fibrillation



Complete disorganization
No P-waves
No QRS complexes
u-wave  electrolyte abnormalities
4