ekg rhythm review - maine cardiovascular health councilmainecardiohealth.org/presentations/2018...
TRANSCRIPT
EKG Rhythm Review
Stephanie Cordwell, BS, NRP
Paramedic Program Director Kennebec Valley Community College
Disclaimer:
I do not have any conflicts of interest or disclaimers*.
*Except…I have about 50 minutes to review a topic that I teach over a semester…
2
3
Course Objectives
Understand the difference between electrical and mechanical cardiac function;
Identify the components of an EKG rhythm strip;
Understand how to interpret 4-lead EKG findings including atrial,
junctional, and ventricular rhythms.
Cardiac cells…
4
• Automaticity • Excitability • Conductivity • Contractility
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ
Cardiac Function…
5
Mechanical Function
Electrical Function
https://theydiffer.com/difference-between-skeletal-and-cardiac-muscle/ Gail Walraven, Basic Arrhythmias, Seventh Edition
©2011 by Pearson Education, Inc., Upper Saddle River, NJ
Mechanical vs. Electrical Function?
6 Gail Walraven, Basic Arrhythmias, Seventh Edition
©2011 by Pearson Education, Inc., Upper Saddle River, NJ https://www.medicalnewstoday.com/articles/258118.php
So…what are we looking for?
7
Bledsoe/Porter/Cherry, Essentials of Paramedic
Care, Second Edition Update
© 2011 by Pearson Education, Inc. Upper
Saddle River, New Jersey
The EKG Paper
8
EKG Paper – measures time & voltage
Horizontally - time
One small box - 0.04 sec
One large box - 0.20 sec
Vertically - voltage
One large box - 0.5 mV
9
The EKG Paper (cont)
Every 3 seconds (15 large boxes) is marked by a vertical line.
This helps when calculating the heart rate.
3 sec 3 sec
Rhythm Interpretation
10
Ga
il W
alra
ve
n, B
asic
Arr
hyth
mia
s, S
eve
nth
Ed
itio
n
©2
01
1 b
y P
ea
rso
n E
du
ca
tio
n, In
c.,
Upp
er
Sa
dd
le R
ive
r, N
J
Calculating Heart Rates
11 Gail Walraven, Basic Arrhythmias, Seventh Edition
©2011 by Pearson Education, Inc., Upper Saddle River, NJ
12
“Normal” Sinus Rhythm Parameters
Rate 60 - 100 bpm
Regularity regular
P waves normal
PR interval 0.12 - 0.20 s
QRS duration 0.04 - 0.12 s
Any deviation from above is sinus tachycardia, sinus bradycardia or a dysrhythmia
13
Dysrhythmia Formation
Dysrhythmias can arise from problems in the:
• Sinus node
• Atrial cells
• AV junction/node
• Ventricular cells
14
SA Node Problems
SA node depolarizing too slow
Sinus Bradycardia
SA node depolarizing too fast
Sinus Tachycardia
*Sinus Tachycardia may be an appropriate response to stress.
Rate
Regularity
P waves
PR Interval
QRS Duration
30 bpm
Regular
Present & upright
0.12 seconds
0.10 seconds
15
Interpretation: Sinus Bradycardia Deviation from NSR? Rate <60 bpm
Rate
Regularity
P waves
PR Interval
QRS Duration
130 bpm
Regular
Present & upright
0.16 seconds
0.08 seconds
16
Interpretation: Sinus Tachycardia Deviation from NSR? Rate >100 bpm
17
Atrial Cell Problems
A single irritable focus within the atria conducted in a rapid and repetitive fashion
Atrial Flutter
Continuous, disorganized firing from multiple foci in the atria
Atrial Fibrillation
Rate
Regularity
P waves
PR Interval
QRS Duration
Averages 100 bpm
Irregularly irregular
none
none
0.06 seconds
18
Interpretation: Atrial Fibrillation Deviation from NSR? Disorganized atrial depolarization; atrial activity is chaotic
Rate
Regularity
P waves
PR Interval
QRS Duration
70 bpm
regular
Flutter waves
none
0.06 seconds
19
Interpretation: Atrial Flutter Deviation from NSR? No P waves; re-entry issue, only some impulses are conducted through
20
AV Junctional Problems
Continuous, rapid, organized firing due to re-entry circus loop at AV junction
Supraventricular Tachycardia
Impulses originating from the SA node are delayed or blocked at the AV junction/node, disrupting ventricular depolarization
AV Blocks
Rate
Regularity
P waves
PR Interval
QRS Duration
160 bpm
regular
Cannot determine
Cannot determine
0.08 seconds
21
Interpretation: Supraventricular Tachycardia
Deviation from NSR? Regular, tachycardic rate, cannot discern P waves
Rate
Regularity
P waves
PR Interval
QRS Duration
60 bpm
regular
normal
0.36 seconds
0.08 seconds
22
Interpretation: 1st Degree AV Block
Deviation from NSR? PR Interval > 0.20 seconds
Rate
Regularity
P waves
PR Interval
QRS Duration
50 bpm
Regularly irregular
normal
lengthens
0.08 seconds
23
Interpretation: 2nd Degree Type I AV Block
Deviation from NSR? PR Interval progressively lengthens until dropped beat, pattern resets
Rate
Regularity
P waves
PR Interval
QRS Duration
40 bpm
Regular
Normal
0.14 seconds
0.08 seconds
24
Interpretation: 2nd Degree Type II AV Block
Deviation from NSR? PR Interval normal when present; occasionally atrial impulse blocked
Rate
Regularity
P waves
PR Interval
QRS Duration
40 bpm
Regular
No relation to QRS
none
Wide (>0.12 sec )
25
Interpretation: 3rd Degree AV Block
Deviation from NSR? Atrial impulses are completely blocked; ventricles working independently.
26
Ventricular Cell Problems
Occasional depolarization from 1 or more foci within the ventricles
Premature Ventricular Complex (PVC)
Rapid, regular depolarization from irritable foci within the ventricles
Ventricular Tachycardia
Disorganized quivering of the heart muscle, ineffective cardiac output
Ventricular Fibrillation
Rate
Regularity
P waves
PR Interval
QRS Duration
40 bpm
varies
Upright when present
0.14 seconds
variable
27
Interpretation: Sinus with Premature Ventricular Contractions (PVC)
Deviation from NSR? Ectopic beat originating in the ventricles resulting in wide, bizarre QRS
Rate
Regularity
P waves
PR Interval
QRS Duration
160 bpm
regular
none
none
Wide (>0.12 seconds)
28
Interpretation: Ventricular Tachycardia
Deviation from NSR? Ventricular cells fire continuously – life threatening dysrhythmia
Rate
Regularity
P waves
PR Interval
QRS Duration
40 bpm
regular
none
none
Wide (>0.12 seconds)
29
Interpretation: Idioventricular
Deviation from NSR? Escape rhythm to prevent complete cardiac standstill
Rate
Regularity
P waves
PR Interval
QRS Duration
irregular
disorganized
none
none
none
30
Interpretation: Ventricular Fibrillation
Deviation from NSR? Multiple ventricular foci firing without effective contractions – life threatening dysrhythmia
Rate
Regularity
P waves
PR Interval
QRS Duration
none
none
none
none
none
31
Interpretation: Asystole
Deviation from NSR? No electrical activity in the heart
Let’s review…
The heart has two functioning systems
The mechanical system = pulse & BP
The electrical system = cardiac monitor
The EKG represents the electrical conduction system and how the various cells are depolarizing and repolarizing
32
Let’s review (continued)…
Upright P waves = atrial depolarization
QRS Complexes = ventricular depolarization
Any deviation from “Normal” Sinus Rhythm is a dysrhythmia, not all deviations are lethal.
33
Lastly…
Rhythm recognition takes lots of practice, think of it like learning another language.
Remember, what you see on the monitor is only telling a small part of the cardiac story for your patient, you must actually touch and assess them.
34