EKG Flashcards
The heard depolarizes from _____ to _____
bottom to top
EKG
- recording of electrical events in heart
- any area of heart
- picked up by electrodes on skin
Depolarization of the SA Node –>
- bachman’s bundles–>R atrium–>L atrium
2. internodal tracts–> AV node –> bundle of His –> R & L bundle branches –>purkinje fibers –>R & L Ventricles
Leads
-the sensing electrodes used to monitor electrical activity
Standard Limb Lead
Lead I: - electrode R arm; + electr L arm
Lead II: - electr R arm; + electr L leg
Lead III: - electr L arm; + electr L leg
Ground: R leg
(Frontal Plane)
Augmented (unipolar) limb leads
-Fills in gaps of standard (frontal)
- aVr= + R arm
- aVl= + L arm
- aVf= + leg (foot)
Normal EKG Speed
25mm/sec
6 Major EKG Deflections
P Q R S T U
PR Interval
- beginning of P wave to beginning of QRS
- Atrial contraction + A-V conduction delay
- flat spot=isoelectric
- 0.12-0.2 sec
Length of PR Interval
- 0.12-0.2 sec
- 3-5 small boxes
R
First + deflection
Small box dimensions
- height: 0.1 mV
- width: 0.04 sec
Precordial (chest) leads
Transverse Plane
V1: R of sternum; 4th intercostal space V2: L of sternum; 4th IC space V3. between 2 & 4 V4: midclavicular; 5th IC space V5: ant axillary line; 5th IC space V6: mid axillary line; 5th IC space
Big square dimensions
- 5x5 small squares
- height: 5mV
- 0.2 seconds
P Wave
- atrial depolarization
- can be positive/neg/biphasic; but must be the same each time
QRS Complex
- Ventricular Depolarization
- Made up of Q, R, S, R^1, S^1 (QS)
Should be <2.5 small boxes
Length of QRS Complex
<2.5 small boxes
S
neg deflection after R
S^1
S prime
neg deflection following R prime
Q
Initial negative deflection before R
R^1
R prime
2nd + Deflection
QS
Total deflection
QT Segment
- beginning of Q to end of T wave
- Should be <1/2 distance of R to R interval (in normal rhythm)
- Prolonged QT bad (increase chance for ectopic foci & arrhythmias
QT Segment Length
<1/2 distance from R to R
U Wave
- uncertain cause
- (final phase ventricular repol)
- same direction as T wave
- not everyone has U wave
PT’s use EKG to:
- determine if pt in normal sinus rhythm
- monitor response to ex’s
Methods to Calculate HR from EKG
- Small box method
- Big Box method
- 6 Sec strip
ST Segment
-end QRS to beginning of T wave
-represent beginning of ventricular repolarization
-usually isoelectric (Flat)
(-beginning called J point)
J Point
- point where ST segment begins
- where thin line becomes thick
Small Box Method
bpm=1500/# small boxes between successive R waves
6 Second Strip
bpm=# Cycles in 6 Sec X 10
use only fro slow HR
How to get HR when Irregular
bpm=# cycles in 15 sec X 4
5 sections of 3 seconds
(75 big boxes=15 sec)
Sinus Bradycardia
- all perfect except rate
- Atrial rate 40-50bpm (or slower)
- Ventricular Rate: <60 bpm (same as atrial rate)
-PT assess and treat if asymptomatic
Sinus Tachycardia
- everything perfect but rate
- Atrial Rate: >100bpm
- Ventricular Rate: >100bpm (same as atrial rate)
PT: assess and treat if asymptomatic
Large box Method
-# large boxes between successive R waves
300/150/100/75/60/50/42/35
Normal Sinus Rhythm
- Rhythm: normal
- Atrial/Ventricular Rate: 60-100bmp
- P Wave: all same; 1 per QRS; upright in lead II
- PR Interval: 3-5 sm boxes
- QRS: all same; < 2.5 sm boxes; one per P wave
- T wave: same direction as P
Third Degree Heart Block (CHB)
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: regular but ventr and atrial rates different
b. atrial rate: normal
c. ventricular rate: 20-60bpm
d. P wave: normal (not related to QRS)
e. PR: none
f. QRS: junctional pacemaker=normal QRS; ventricular focus=QRS >0.11 sec
g. T wave: not uniform
h. mechanism: complete block between SA to AV (artia & vent contractions unrelated)
i. PT: no PT, medical emergency
Left BBB
Rabbit ears on V6
Right BBB
Rabbit ears on V1
Asystole
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: none
b. atrial rate: none
c. ventricular rate: none
d. P wave: none
e. PR: none
f. QRS: none
g. T wave: none
h. mechanism: no electrical activity in atria or ventr
i. PT: medical emergency; CPR
PAC
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: irregular @ site of PAC; R-R shorter before, longer after
b. atrial rate: normal
c. ventricular rate: normal
d. P wave: all same but premature; 1 per QRS
e. PR: 3-5 small boxes
f. QRS: normal
g. T wave: same direction as P
h. mechanism: ectopic atrial focus
i. PT: usually OK; high frequency can–> a-fib
Atrial Flutter
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: regular/irreg
b. atrial rate: 250-300 bpm
c. ventricular rate: depends on ratio of conduction
d. P wave: “F” waves=sawtooth
e. PR: none
f. QRS: usually normal
g. T wave: covered by F waves
h. mechanism: ectopic atrial focus takes over normal pacemaker activity
i. PT: do PT if asymptomatic (chronic fluttter)
Atrial Fibrillation
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: irregularly irregular
b. atrial rate: >350 bpm; can’t count on EKG
c. ventricular rate: normal/slow/fast but irregular
d. P wave: none, jagged baseline
e. PR: none
f. QRS: usually normal
g. T wave: altered/obliterated by fib waves
h. mechanism: chaotic atrial activity–>loss atrial kick–>decr ventr filling–> decr CO by 30%
i. PT: high clot risk
PVC
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: irregular due to premature beats
b. atrial rate: depends on underlying rhythm
c. ventricular rate: depends on underlying rhythm
d. P wave: none w/ PVC, others normal
e. PR: none w/ PVC, others normal
f. QRS: >0.11 sec, usually >0.16 sec
g. T wave: none after PVC, others normal
h. mechanism: ectopic focus
i. PT: some PVC normal; notify Dr if >6/min or couplets/triplets or every other
V-Tach
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
“picket fence”
a. rhythm: regular
b. atrial rate: none
c. ventricular rate: 100-250bmp
d. P wave: none
e. PR: None
f. QRS: weird/bizzare; 3+ PVC in row diagnoses V-tach
g. T wave: none
h. mechanism: single ventricular focus
i. PT: med emergency; no PT; CPR, Defibrillation
V-Fib
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: irregular
b. atrial rate: none
c. ventricular rate: none
d. P wave: none
e. PR: none
f. QRS: none; fibrillation fine or coarse
g. T wave: none
h. mechanism: multifocal irritation; chaotic activity
i. PT: medical emergency; no PT; CPR; defibrillation
First Degree Heart Block
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: regular
b. atrial rate: 60-100bpm (or slower)
c. ventricular rate: same as atrial rate
d. P wave: uniform/normal; 1 per QRS
e. PR: consistent but >0.25 sec (>3-5 sm boxes)
f. QRS: normal
g. T wave: normal
h. mechanism: AV node sick & slow
i. PT: do PT; unless change in EKG
Second Degree Heart Block Type I (Wenckebach)
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: regularly irregular
b. atrial rate: 60-100bpm
c. ventricular rate: slower than A rate
d. P wave: normal; some don’t have QRS (droppped beats)
e. PR: progressively longer until QRS dropped, then start over
f. QRS: normal
g. T wave: normal
h. mechanism: block high in junction
i. PT: do PT with Dr. clearance
Second Degree Heart Block Type II (Mobitz)
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: regularly irregular
b. atrial rate: 60-100bpm
c. ventricular rate: regular but diff than atrial rate
d. P wave: normal; not a QRS for each
e. PR: normal if QRS present
f. QRS: normal
g. T wave: normal
h. mechanism: block low in bundle of His
i. PT: no PT; CO compromised
PR consistent but too long with dropped QRS
BBB
a. rhythm
b. atrial rate
c. ventricular rate
d. P wave
e. PR
f. QRS
g. T wave
h. mechanism
i. PT
a. rhythm: regular
b. atrial rate: normal
c. ventricular rate: same as atrial rate
d. P wave: normal
e. PR: normal
f. QRS: >0.11 sec
g. T wave: normal
h. mechanism: delay of action potential in one bundle branch
i. PT: do PT unless new or change
