This document provides an overview of basic cardiac dysrhythmias including atrial fibrillation, atrial flutter, premature atrial complexes, wandering atrial pacemaker, junctional escape rhythms, accelerated junctional rhythms, premature junctional complexes, and supraventricular tachycardia. It describes the characteristics, causes, concerns and treatment approaches for each of these arrhythmias.

1. Basic Cardiac Dysrhythmias
Atrial and Junctional Rhythms
Rev 2016

2. Atrial Fibrillation
Rate: Variable, Atrial Rate 400bpm or greater (immeasurable) Ventricular
Rate 60-100bpm considered “Controlled”, below 60bpm termed A. Fib
with Slow Ventricular Response, above 100 considered Rapid A. Fib
Regularity: Irregularly Irregular
P Wave Morphology and AV Ratio: No prominent P waves present. Fine
fibrillatory waves (f waves) visible as almost flat line.
PR Interval: Immeasurable
QRS Duration and Morphology: Less than 120ms (0.12seconds). Identical
Morphology
QT Interval: Less than ½ the preceding R-R Interval

3. Atrial Fibrillation
Causes: many different sites of both atria, and sites in
the pulmonary veins that are irritable, and firing
rapidly, and irregularly.
Causes of the irritable cells include: Hypoxia, Ischemia,
Infarction, Electrolyte disturbances Hypervolemia
(causes stretch of the atria), Cardiac Surgery (50% of
Valve surgery patients develop AF, approx. 25% of
CABG patients develop AF), Excessive adrenergic
stimulation (catecholamine surge from stress,
surgery), Cardiomyopathy, CHF, Pericarditis,
Alcohol Withdrawal, Hyperthyroidism.

4. Atrial Fibrillation
Concerns: Atrial Fibrillation is the most common
dysrhythmia.
Patients can live with permanent AF.
1) Rate control
2) Prevent Clot Formation
3) Loss of Cardiac Output form “Atrial Kick”

5. Initial Treatment of Atrial Fibrillation
Rate Control: Initial treatment is with β-adrenergic
blockers or Calcium Channel Blockers. These
medications the have negative chronotropic and/or
negative dromotropic properties (slow speed of
conduction through AV node) Amiodarone is not
recommended as a first line treatment due the drug’s
extensive side effect/adverse reaction profile.
Anticoagulation: If the underlying etiology cannot be
corrected, or the rhythm cannot be converted within
24 hours, anticoagulation is indicated to prevent
blood clot formation.

6. Conversion of Atrial fibrillation to
Sinus Rhythm
Ideally, treatment of atrial fibrillation includes
correcting the rhythm disturbance and conversion
to sinus rhythm. This is not always possible for all
patients.
Methods to achieve this goal include: Antiarrhythmic
Drugs: Propafenone, Flecainide, Sotalol,
Dofetilide, Amiodarone, Dronedarone
Cardioversion EP Procedures MAZE

7. Atrial Flutter

8. Atrial Flutter
Rate: Atrial Rate 250-400, Ventricular Rate Variable
Regularity: Atrial Regular, Ventricular-Variable
dependent on A:V
P Wave Morphology and AV Ratio: Fast “saw-tooth”
or “picket fence” Flutter waves (F waves) Present
and Uniform. AV Ratio can be fixed as 3:1, 4:1
etc. (and the Ventricular Rhythm is regular) or
variable (Variable Conduction Ratio).
PR Interval: Immeasurable
QRS Duration and Morphology: Less than 120ms
(0.12seconds). Identical Morphology
QT Interval: Less than ½ the preceding R-R Interval
Treatment: similar to Atrial fibrillation- responds
better to cardioversion

9. Premature Atrial Complexes (PACs)
By Definition, PACs are early beats that come from the Atria
PACs make the Ventricular Rhythm Irregular, they can occur
as occasional or frequent individual beats or in patterns
such as Bigeminy, or Trigeminy
PACs can be Unifocal or Multifocal (coming from multiple
areas of the atria, and having multiple P wave morphologies).

10. PACs
QRS Duration and Morphology: Less than 120ms
(0.12seconds) if conducted through the His-
Purkinje System in a normal fashion. If the QRS
following the P wave of a PAC is wider than the
other QRS Complexes, the impulse has depolarized
the heart in an aberrant fashion. (Those beats are
called PACs with aberrant conduction)
PACs indicate that an area, or areas of the atria are
irritated. PACs are often precursor beats to Atrial
Fibrillation and Atrial Flutter.
Treatment for “high-risk” groups.

11. Wandering Atrial Pacer
Rate: Usually between 60-100bpm, termed Multiple Atrial Tachycardia if
above 100bpm
Regularity: Regular or Irregular
P Wave Morphology and AV Ratio: At least 3 different P wave
Morphologies by definition. A:V ration 1:1.
PR Interval: Will Vary Depending on Location of Ectopic Atrial Sites, and
some may be less than 120ms(0.12seconds).
QRS Duration and Morphology: Less than 120ms (0.12seconds).
QT Interval: Less than ½ the preceding R-R Interval

12. WAP
In WAP, multiple sites, including the SA node, the
Atria and the AV node compete for pacing the heart.
It is a sign of increased autorhythmicity of the various
pacing sites of the heart.
Causes: Common causes include mitral or tricuspid
valve disease, chronic lung disease, digitalis
preparations or enhanced vagal tone.
Patients usually asymptomatic. Discontinue or
change dosage of any medications thought to
be the cause of the arrhythmia.

14. Junctional Escape Rhythms
Rate: 40-60bpm
Regularity: Regular
P Wave One of three morphologies as described on
previous slide
AV Ratio: Retrograde P waves before or after the
QRS complexes, or No visible P waves
PR Interval: PR Interval is less than 120ms (0.12 sec)
if P waves are prior to QRS complexes
QRS Duration and Morphology: Less than 120ms
(0.12seconds).
QT Interval: Less than ½ the preceding R-R Interval

15. Junctional Escape Rhythm
The AV junction is the second line of defense
in the hierarchy of pacemakers. evidence of
a junctional rhythm may be protective for a
patient with impaired SA node
autorhythmicity.
Common causes include damage to the SA
node from MI, or ischemia, calcification,
Valvular heart disease, and Myocarditis,
CHF and Digitalis Toxicity.

16. Accelerated Junctional and Junctional
Tachycardia Rhythms
Rate: Accelerated = 60-100 bpm Tachycardia=
greater than 100 bpm
P Wave Morphology: Same P wave morphologies as
Junctional Escape Rhythms
PR Interval: Short if Measurable

17. Accelerated Junctional Rhythm
Causes: Enhance Autorhythmicity of Junction
including Digitalis or Theophylline toxicity,
catecholamine surge from stress or stimulants,
or acid base imbalances.
Treatments: Treatment is based on removal of
cause, and control of heat rate. Meds that limit
the automaticity of the Junction include β-
Blockers, Ca Channel Blockers and
Amiodarone,

18. Premature Junctional Complexes
(PJCs)
By Definition, PJCs are early beats that originate
from the Junction
PJCs take on the same morphology as Junctional Escape
Rhythms, with either Retrograde P waves prior to or
after the QRS complexes, or No Visible P waves.

19. Supra-Ventricular Tachycardia (SVT)
Fast Rhythms:
First Discern if the Rhythm comes from the ventricle
(wide QRS complex), or from above the ventricle
(Narrow QRS complex).
Then Identify the specific origin of the Rhythm.

20. Treatment of SVTs
Serious signs and symptoms (hypotension,
acutely altered mental status, signs of shock,
ischemic chest discomfort, acute heart failure):
1. Immediate Synchronized Cardioversion
2. Consider adenosine (now also first line)
Stable without rate related CV compromise:
1.Attempt to visualize the origin of the SVT
by using vagal maneuvers or adenosine.
2. Slow the ventricular response using Ca
channel blockers or B-adrenergic blockers.

21. Synchronized Cardioversion
Goal: spontaneous depolarization of a “critical
mass” of cardiac cells to disrupt the erratic
tachycardia, with hope that the conduction
system will restore normal function.
Synchronized with the patient’s rhythm to
deliver the electrical current on the R wave to
prevent deterioration to less viable rhythm.
Painful: provide analgesia, and anxiolytics

22. Vagal Maneuvers
Bearing down
Coughing
Suctioning
Deep Held Breath
Digital Rectal Stimulation
Vomiting
Carotid Sinus Massage (Only advanced, insured
practitioners, after checking for bruits)

23. Adenosine
Used as a diagnostic tool to help identify
rhythm.
Adenosine
6mg IVP, “high and fast”
May repeat with 12 mg, q 1-2 min x 2
Predictable signs and symptoms: CP, palpitation,
LOC, SOB diaphoresis – please inform patient