This document discusses cardiac arrhythmias and the cardiac conduction system. It describes the sinoatrial node, atrioventricular node, and Purkinje fibers, which make up the cardiac conduction system. Causes of arrhythmias include enhanced automaticity, triggered activity, and re-entry. Various arrhythmias are described including sinus bradycardia, premature atrial contractions, atrial fibrillation, premature ventricular contractions, ventricular tachycardia, and different types of atrioventricular block. The electrocardiogram is discussed as a tool to evaluate heart rate, intervals, waves, and diagnose arrhythmias.

1. CARDIAC ARRYTHMIAS
ORHAN HAKLI, NP

2. CARDIAC CONDUCTION SYSTEM
SA NODE :
-AT THE UPPER POSTERIOR PART OF THE ATRIUM
-PRIMARY PACEMAKER
-DISCHARGES ELECTICAL IMPULSES 60-100 A
MINUTE
AV NODE :
-RECEIVES IMPULSES FROM SA NODE
-SLOW THE CONDUCTION AND DELAYS THE
INPUT IN ORDER ATRIUMS TO VENTRICULS
COMPLETELY(Atrial kick 5-30% of the CO)
-BLOCK SOME OF THE IMPULSES TO PREVENT
GOING THE HEART TACHY
-SERVES AS A BACK UP PACEMAKER IF SA NODE
FAILS (ELECTRICAL IMPULSES OF 40-60 A MINUTE)
PURKINJE FIBERS:
-RECEIVES IMPULSES FROM BUNDLE
BRANCHES
-DISCHARGES ELECTRICAL IMPULSES 20-40
A MINUTE

3. CAUSES OF DYSRHYTHMIAS
ENHANCED
AUTOMATICITY
Increased activity or
rhythm disturbances
TRIGIRRED ACTIVITY
Abnormal electric
impulses when cells are
at rest
RE-ENTRY
Spread of an impulse
through tissue already
stimulated by that same
impulse
ACIDOSIS HYPOXIA HYPERCALIMIA
ALCOLOSIS HYPOMAGNESIA MYOCARDIAL ISCHEMIA
HYPOXIA MYOCARDIAL INJURY ANTIARYTHMATIC MEDS
ISCHEMIA/INFARCT MEDICATIONS THAT
PROLONGS
REPOLARIZATION
(IE.QUINIDINE)
ELECTROLYTE
PROBLEMS (K-CA)
DIG.TOXICITY
ADMINISTRATION OF
ATROPINE/
EPINEPHRINE

4. EKG
HEART RATE
-To determine the ventricular rate, count
the QRS complex on a 6 sec paper and
multiply by 10
WAVES
-P wave: atrial depolarization
-QRS complex :ventricular depolarization
-Twave :Ventricular repolarization
INTERVALS
-PR :0.12-0.20 sec
-QRS :under 0.10sec
-QT:under 0.38 sec

5. MAJOR CARDIAC ARRHYTHMIAS
SINUS RYTHMS ATRIAL
RYTHMS
VETRICULAR
RHYTHMS
ATRIO-
VENTRICULAR
(AV) RHYTHMS
SINUS BRADY PREMATURE
ATRIAL
CONTRACTION
(PAC)
PREMATURE
VENTRICULAR
CONTRACTION
(PVC)
1ST DEGREE AV
BLOCK
SINUS
TACHICARDIA
ATRIAL
FLUTTER
VENTRICULAR
TACHICARDIA
2ND DEGREE AV
BLOCK TYPE I
SINUS
ARRYTHMIA
ATRIAL
FIBRILATION
VENTRICULAR
FIBRILATION
2ND DEGREE AV
BLOCK TYPE II
SINUS ARREST ASYSTOLE 3RD DEGREE AV
BLOCK

6. SINUS RHYTMS
CHARACTERISTICS
-less than 60bpm
-regular PP and RR
-PR 0.12-.20
QRS0.10
WHAT TO DO?
-watch the patient for s/s of bradycardia
-If symptomatic; iv access, o2, transcuteneus pacing
MEDICATION
Atropine 0.5mg ivp

7. SINUS RHYTHMS
 CHARACTERISTICS
 - 101-150bpm
 -regular PP and RR
 -PR 0.12-.20
 QRS0.10 or less
 WHAT TO DO?
 -watch the patient for s/s of Tachycardia
 -correct underlying problems/Never shock ST
 MEDICATION
 Atenelol/Meteprolol (Beta blockers)

8. SINUS RHYTHMS
 CHARACTERISTICS
 - usually 60-100bpm, but can be slower or faster
 -irregular with respiration, HR increases with inspiration
and decreases with expiration
 -PR 0.12-.20
 QRS0.10 or less
 WHAT TO DO?
 NOTHING !!!
 MEDICATION
 If hemodynamic compromise is present ATROPINE

9. SINUS RHYTHMS
 CHARACTERISTICS
 - Rate varies because of the pause
 -irregular rhythm
 -PR 0.12-.20
 QRS0.10 or less
 WHAT TO DO?
 If transient and major s/s of decline monitor the pt
 If more than 3 sec. ATROPINE, Bedside Pacer or
Possible Permanent PM insertion
 MEDICATION
 ATROPINE
SINUS ARREST

10. ATRIAL RHYTHMS
 CHARACTERISTICS
 - Rate; Depends on the underlying rhythm but usually w/i normal
limits
 -Regular rhythm, except the premature beats
 -PR may be normal or prolonged
 QRS0.10 or less but might be wide
 WHAT TO DO?
 NOTHING!!!
 Reducing stress, stimulants(coffee), treating CHF may help
 MEDICATION
 If needed beta blockers, CA blockers or anxiety meds
PREMATURE ATRIAL COMPLEX

11. ATRIAL RHYTHMS
AFIB
AFLUTTER

12. VENTRICULAR RHYTMS
PREMATURE VENTRICULAR COMPLEX
 CHARACTERISTICS
 - Rate; Depends on the underlying rhythm
 -Regular rhythm, except the premature beats
 -PR no PR because ectopy comes from ventricles
 QRS more then 0.12, wide and bizarre looking
 WHAT TO DO?
 NOTHING!!!
 Monitor the pt, if frequent check if they have enough cardiac output

13. VENTRICULAR RHYTHMS
VENTRICULAR TACHICARDIA
VENTRICULAR FIBRILATION
ASYSTOLE

14. ATRIOVENTRICULAR (AV) BLOCKS
 CHARACTERISTICS
 - Rate; Depends on the underlying rhythm, but usually normal
 -Regular rhythm
 -PR prolonged, greater than 0.20 sec
 QRS usually 0.10 sec or less
 WHAT TO DO?
 They are usually asymptomatic, Monitor the pt if MI is causing the
block
 Hold the meds that could cause the block(IE beta blockers, CA
blockers, Dig, quinidine)
FIRST DEGREE AV BLOCK

15. ATRIOVENTRICULAR (AV) BLOCKS
 WHAT TO DO?
 They are usually asymptomatic, Monitor the pt
 Do not give ATROPINE to increase the heart rate
 Type II might be indication for PM
 Hold the meds that could cause the block(IE beta blockers, CA
blockers, Dig, quinidine)
 If associated with MI, watch if the block is getting worse
SECOND DEGREE AV BLOCK
TYPE -I
TYPE -II

16. ATRIOVENTRICULAR (AV) BLOCKS
 CHARACTERISTICS
 - Rate; atrial rate is greater then ventricular rate
 -Regular ratrial (P) and regular ventricular but no relationship
between the two
 -P normal size and shape; PR none
 QRS can be narrow or wide
 WHAT TO DO?
 ATROPINE /Transcuteneus Pacing
 Possible permanent Pacemaker
THIRD DEGREE AV BLOCK

17. REFERENCES
 Aehlert, B. (2006). ECGs Made Easy. Arizona: Sauthwest EMS
education Inc.
 Heart Blocks. (2012). Retrieved from http://www.nhlbi.nih.gov:
http://www.nhlbi.nih.gov/health/health-topics/topics/hb/types.html
 Huff, j. (2006). ECG Workout: Exercises in Arrhythmia Interpretation. PA:
Lippincott Williams & Wilkins.
 Nicod, P.; Hillis, L.; Winniford, M.D.; Firth, B.G. (February 15, 1986).
Importance of the "atrial kick" in determining the effective mitral valve
orifice area in mitral stenosis. The American Journal of Cardiology ,
Volume 57, issue 6 p. 403-407.
 Sauer, W. (2012). Normal sinus rhythm and sinus arrhythmia. Retrieved
from http://www.uptodate.com:
http://www.uptodate.com/contents/normal-sinus-rhythm-and-sinus-
arrhythmia
