COMPS:Unit 1: EKG Extra Stuff You Need to Know!!! Flashcards
What is ECG of EKG???
- Represents the electric impulses of the heart
- hearts functioning SHORT TERM
- Halter/Telemetry
- LONG TERM
ECG ===
- Graphic rep of hearts electrical activity
- provides info about hearts function
Why do PTs need to learn EKG??
4 Reasons:
- Basic anatomy & phys of heart–> norm vs. patho
- PT implications of rhythms –> norm vs. patho
- Diff b/w benign vs. life-threatening arrhythmias
- Read physicians notes on 12 lead EKG AND understand implications
Myocytes….
What are they?
cells of myocardium
3 Properties of Myocytes
- Automaticity
- Rhythmicity
- Conductivity
Properties of myocytes
1. Automaticity
explain…
*Discharge e-stim w/out nerve impulse (automatic)
-
SA Node (natural pacemaker of heart)
- 60-100bpm
-
AV Node (backup pacemaker)
- 40-60bpm
- kicks in to keep adequate HR
-
Perkinje (next backup Pacemaker)
- 30-40bpm
Properties of myocytes
2. Rhythmicity
explain…
*Spontaneous depolarization/repolarizatoin
*rhythmically fires
Properites of Myoctyes
3. Conductivity
explain..
*Carry rhythmic control from cell to cell (W/in OWN cells)
*Carry muscle to muscle
*NO NEURAL INPUT NEEDED
A DEPOLARIZATION wave will be a ________deflection
*Influx of Na+
POSITIVE deflection
A REPOLARIZATION wave will be _______ deflection
NEGATIVE deflection
ECG and Electrical Activity of the Myocardium
The Conduction System
see pics
ECG and Electrical Activity of the Myocardium
The Conduction System
More pics
Conduction System
P Wave===
Atrial Depolarization
*SA node fired B/L Atria
Conduction System
QRS Complex ====
Ventricular depolarization AND contraction
*AV node fired
NOTE: Atrial Repolarization hidden in QRS complex
Conduction system
T wave===
Ventricular Repolarization
Conduction system
Pics
Conduction System
All ECG components broken down
see pics
What lead is MOST COMMONLY recorded in an ECG?
Lead 2 !!!
Lead II:
Wave of Depolarization moving toward positive electrode==
+ Deflection
Lead II:
Repolarization moving towards positive electrode==
- Deflection
Lead II is used to determine ______ and ______
Rate and Rhythm
*Matches the angle of the heart along the axis of depolarization
Off of Lead II…
What do we interpret?
- Rate
* 3 methods
* ONLY METHOD 1 FOR IRREGULAR RHYTHMS
- Rate
- Regularity
- P wave
* Y/N?
* Upright?
* 1 for ea. QRS?
- P wave
- PR interval
* tiny boxes x.04
- PR interval
- QRS width
* tiny boxes x.04
- QRS width
Off of 12 Lead
What do we interpret?
- Axis
- Hypertrophy
- Ischemia/Infarction
PR Interval
What is NORMAL?
.12 (3 sm. boxes)–.20 (5 sm. boxes)
QRS width
What is NORMAL?
.06 (1.5 sm. boxes)–.10 (2.5 sm. boxes)
Rate
3 methods to determine rate
- R waves per 6sec strip x 10==Rate
- 300, 150, 100, 75, 60, 50…(make sure one of the QRS is right on the line)
- 300/# of Lg. boxes w/in 2 R waves
Measuring PR interval
Where to Where?
see pics
QRS Width
Where to Where ?
see pics
Normal Rhythms:
What are they
5
*ALL FROM SA NODE*
- NSR
- Sinus Tachy
- Sinus Brady
- NSR w/ Pause
-
Sinus Arrhythmia
- arrhythmia literally means “irregular rhythm”
- all else will be NORMAL
Normal rhythms
Whats Different
Whats Normal
-
NORMAL
- PR interval
- QRS width
-
DIFFERENT
- rate
- regularity
Sinus Bradycardia
Keep in mind…
NORMAL BUT Rate <60
*In high lvl athletes this is normal
Sinus Tachycardia
Keep in mind…
NORMAL BUT Rate >100bpm
Sinus Arrhythmias OR aka…
The Inspiration (faster) vs. Expiration (slower) one
*IRREGULAR so must use Method 1***
Sinus Pause OR
Other names ?
Sinus Block
Sinus Arrest
NSR w/ pause
*skipped beat/pause
*SA node fails to fire
Atrial Arrhythmias
*Occur in Atria!
5:
- Wandering Atrial Pacemaker
- @ least 3 diff. P-wave shapes!
- PAC
- has a P wave! diff. shape OR inverted
- Atrial Tachycardia (SVT)
- Atrial Flutter (Sawtooth)
- A-Fib
**ALL ectopic==> SA fires when should NOT
ONLY NORMAL THING W/ ATRIAL ARRHYTHMIAS
QRS Width bc QRS complex is ventricles and Atrial Arrhythmias are occurring in the Atria
Wandering Atrial Pacemaker
Keep in mind…
- Random ectopic foci
- P-wave constantly changing
- @ least 3 diff.
PAC
Keep in mind
- P-wave embedded in the T (Tall T)==PAC
- OR
- Tall T==PAC
Premature Beats
Compensatory (use 3 line rule)
match 1 and 3 up w/ 1 and 3 w/ premature beat in the middle and 1 and 3 should still line up….if NOT==NON-comp
- Pause following ectopic beat which allows reg rhythm to resume w/ next normal beat @ its orig. projected timing
Premature Beats
NON-compensatory
1 and 3 will NOT line up!!!
- Pause not long enough to allow rhythm to resume its original rhythm and timing
Which PAC compensation (NON-comp vs. COMP) represents a healthier SA Node?
Complete COMPENSATORY Pause
*SA goes back to firing Normal
3+ PAC in a row====
Atrial Tachycardia OR SVT
Atrial Tachycardia
3+ PAC in a row*
Other names?
Paroxysmal Atrial Tachy
Paroxysmal Junctional Tachy
Supraventricular Tachy (SVT)
Atrial Tachycardia or SVT
*remember this is w/ NO ACTIVITY we call it SVT otherwise WITH Activity we call it Sinus Tachy
Keep in mind…
- Tachy occurs ABOVE AV node
- rate always elevated
- common
- NOT benign
- Usually older adults w/ comorbidities
Rate for SVT (Tachycardia)
150-250bpm
EXAMPLE
NSR into SVT
see pics