Download learning activity module - selu moodle

CARDIOVASCULAR
LEARNING ACTIVITY MODULE
SOUTHEASTERN LOUISIANA UNIVERSITY
DEPARTMENT OF NURSING
NLAB 335
Developed by: M. Wafer, Fall, 1997
Revised by: L. Larsen, Spring, 1998; R. Rolling, Fall, 2000; Fall 2003, Fall 2005; Fall 2007
Landry/Vessel Spring 2008, TV Fall 2008, Landry/Guillot Spring 2009
Revised: D. Guillot, Fall 2013, Su 2014, Fall 2015, March 2017
1
LEARNING ACTIVITY MODULE
EKG INTERPRETATION
Purpose:
The purpose of this learning activity module is to introduce students to the
following:
a.
proper electrode placement for basic cardiac monitoring
b.
basic identification of an EKG rhythm strip
c.
how to defibrillate or perform synchronized cardioversion
d.
how to manage a cardiac arrest utilizing Sim-Man scenario
Rationale:
The ability to monitor a client’s cardiac status and to recognize and manage
common abnormal rhythms is an essential skill for the nurse.
Objectives:
The learner will be able to:
1.
2.
3.
4.
Demonstrate proper lead placement for 3 lead & 5 lead cardiac
monitoring
Analyze each component of an EKG wave form
Utilize a 5-step method to interpret a EKG rhythm strip
Identify the following dysrhythmias:











5.
6.
7.
normal sinus rhythm
sinus bradycardia
sinus tachycardia
atrial fibrillation
atrial flutter
premature ventricular contractions (PVCs)
ventricular tachycardia
ventricular fibrillation
asystole
pulseless electrical activity (PEA)
supraventricular tachycardia
Demonstrate defibrillator safety to include clearing area, charging,
discharging, and how to use various defibrillator pads
Differentiate between defibrillation and synchronized
cardioversion.
Effectively manage a cardiac arrest scenario utilizing Sim-Man.
Readings:
Lynn, P. (2015). Taylor’s clinical nursing skills: A nursing process approach. (4th ed.)
Philadelphia: Lippincott Williams & Wilkins.
2
Key Terms
Box 16-1
Skill 16-5
Skill 16-7
I.
ECG Complex
Applying a Cardiac Monitor
p. 915-916
p. 938
p.943-948
Performing Emergency Manual External
Defibrillation (Asynchronous)
p. 932-936
The EKG
The electrocardiogram (EKG) is a graphic recording of the electrical potentials produced
in association with the heartbeat. Impulse formation and conduction produce weak
electrical currents that spread throughout the entire body. By applying electrodes to
various positions on the body and connecting these electrodes to an electrocardiographic
apparatus, the EKG is recorded. Examples of the electrocardiograph include the standard
EKG machine, bedside monitors, or telemetry monitors.
The placement of electrodes record waveforms, which look different in different
positions. The most common lead placement for continuous monitoring is Lead II.
Lead placement should be coordinated with the monitoring operating system according to
manufacturer directions.
The EKG is recorded on ruled paper, which measured horizontally, represents time, and
vertically, distance. The time measurements are important in dysrhythmia recognition.
The EKG is usually recorded at the standard paper speed of 25 mm/second or 1
inch/second thus, the time value of each small square is 0.04 seconds and the value of
each large square (5 small squares) is 0.2 seconds, which represents distance in mm.
Vertically, the value of each small square is 1 millivolt in amplitude
3
II. Cardiac Conduction System





SA node (sinoatrial) is located in the upper right atrium near the junction of the
superior vena cava and the right atrium.
o SA node cells have highest automaticity and fastest rate of impulse
formation at 60 –100/ minute
o Considered the pacemaker of the heart
AV node (atrioventricular) is located in the posterior floor of the right atrium at
the upper portion of the intraventricular septum.
o Conduction slows down here to allow adequate time for the atria to fully
contract completely filling the ventricular chambers
o Automatic rate of impulse formation is 40-60/minute
Bundle of His (common bundle) had direct continuity with the lower portion of
the AV node in the intraventricular septum
Right and left bundle branches continue from the Bundle of His and transmit
impulse through the intraventricular septum
Purkinje fibers connect the bundle branches directly to myocardial cells through
the intricate network
4





P wave- Deflection produced by atrial depolarization
P-R interval – Occurs from the beginning of the P wave (atrial depolarization) to
the beginning of the QRS complex (ventricular depolarization)
o Measures total atrial conduction time
o Normal P-R interval is 0.12 – 0.20 seconds (varying depending on heart
rate
o A longer interval indicates first degree heart block
QRS complex – Deflection or series of deflections produced by ventricular
depolarization
o Normal QRS interval is 0.06 – 0.11 seconds
o If it is 0.12 seconds or above, there is definite delay in conduction through
the ventricle
ST segment – From the end of the QRS complex (ventricular depolarization) to
the beginning of the T wave (ventricular repolarization)
o Segment is usually isoelectric or flat
o Elevation or depression may represent injury or disease of ventricular
muscle
o If not smooth, look for a P wave in it
T wave – Deflection produced by ventricular repolarization
o Peak of the T is the most vulnerable (relative refractory period)
5
III. 5 – Step Plan to Analysis of EKG Rhythm Strip
1.) Analyze the rate –
 Measure both the atrial rate and ventricular rate
 Rates below 60 are bradycardias
 Rates above 100 are tachycardias
2.) Analyze the rhythm
 Use paper or calipers
 Measure the regularity of the rhythm
 Look for consistency in P-P intervals (atrial rhythm) and R-R intervals
(ventricular rhythm)
3.) Analyze the P wave and P-QRS relationship
 Should be upright and smooth in Lead II
 In a normal sinus rhythm every P wave is followed be a QRS complex.
4.) Analyze the P-R intervals
 All P-R intervals should be the same
 P-R interval should be within .12 -.20 seconds
 Shorter or longer P-Rs usually are caused by a conduction defect
5.) Analyze the QRS intervals
 Each QRS should be similar in appearance
 QRS should be no greater than 0.11 seconds
 QRS 0.12 or longer denotes a delay in ventricular conduction, usually a
bundle branch block
6
7