EKG Flashcards
A dysrhythmia originating in an ectopic site in the ventricles causing the QRS complexes to appear abnormally wide and bizarre
Ventricular Tachycardia
Rate of VT
110-250 bpm
Characterized by rapid, chaotic firing of numerous ectopic sites in the ventricles causing the ventricles to quiver; grossly irregular rhythm.
Ventricular Fibrillation
No QRS complexes are present; no cardiac output and no pulse present! (=DEAD)
Ventricular Fibrillation
Bizarre
Tachycardia
Chaotic
Fibrillation
Chaotic QRS complexes
V fib
Bizarre QRS complexes
V tach
AV node pulse
40-60 bpm
SA node pulse
60-100 bpm
purkinje fibers pulse
20-40 bpm
P wave
atrial contraction or depolarization
normal QRS interval
0.04-0.12 seconds
T wave
ventricular relaxation or repolarization
The normal PR interval
0.12-0.20 seconds
Normal QT interval
0.36-0.44 seconds (adjusted for HR)
One small box
0.04 seconds
One large box
0.20 seconds
Wide, irregular QRS with prolonged intervals.
Idioventricular
Absence of all electrical activity within the ventricles.
No HR, no pulse, no rhythm (“flat line”); or if P waves are present but no QRSs, there is no output from the heart- no pulse.
Aystsole/ Ventricular standstill
Prolonged PR interval- greater than 0.20 seconds
1st Degree Heart Block
a. Progressing lengthening of the PR Interval, until a P wave is conducted with no QRS following it.
b. Cycle of lengthening PR Intervals will repeat, causing “groups” of the same pattern.
c. Rate is normal.
d. R to R interval is irregular- due to dropped QRSs.
2nd Degree Heart Block- Type I
a. You will see “grouped beating”—groups of ECG complexes, then a pause with one or more P waves and no QRS following them.
b. This “grouped beating pattern” then repeats itself- This makes the rhythm
irregular (the QRSs are irregular—because one or more QRS is “missing” after
the extra P waves between groups).
c. The PR Interval is “fixed” or “consistent” across the ECG rhythm strip (except
where no QRS follows the extra P wave/ waves).
2nd Degree Heart Block- Type II
a. Also known as Complete Heart Block.
b. AV Dissociation- is like a “divorce” between the atria and ventricles- they have nothing to do with each other any longer.
c. Will see regular, independent “P” waves (rate usually 60- 100) and regular, independent QRS complexes (rate usually 20 - 40).
d. Waves “march” regularly down the baseline-there is no association between the P waves and QRSs.
Third Degree Heart Block
Normal SpO2 readings
94% to 100%.
QT high limit in our monitors is
500ms
prolonged QT may lead to
ventricular dysrthymias
Several medications may prolong the QT interval:
Tikosyn, Amiodarone, Haldol are examples.
The QT interval is defined as
the time between the beginning of the Q wave and end of the T wave, it measures the total duration of depolarization and repolarization phases
The relationship between QT and HR is…
inverse- the higher the HR, the shorter the QT interval:
the monitor uses _______ formula to determine the QTc, which is the QT corrected for HR
Bazett’s
QT alarm/value
Uncorrected QT
QTc alarm/value
Corrected QT
QTc HR
the HR used to calculate QTc
dQTc
delta QTC or the change in QTc from baseline
CANNOT ANALYZE QT
Monitor will say this if QT morphology is too varied to get an accurate measurement
In some situations it may be difficult to obtain reliable QT measurements, therefore it is appropriate to discontinue QT monitoring: (6)
i. Very flat T-wave
ii. Atrial flutter or fibrillation where the T-wave may not be well defined
iii. U-waves obscuring the end of the T-wave
iv. Tachycardia where the P-wave encroaches on the end of the previous T-wave
v. Noise or high QRS morphology variation
vi. Physician order.
The ST segment is an important early indicator of…
cardiac ischemia
all telemetry monitored patients will receive ST segment monitoring unless they meet exclusionary criteria (5)
a. 100% paced
b. Intermittent (not continuous) Right Bundle Branch Block
c. Left Bundle Branch Block with frequent change in heart rate
d. Atrial fibrillation/flutter with very coarse baseline
e. Noisy signal due to restlessness or confusion
You can find type of pacing wires and programmed mode information by:
a. Looking in the patient’s chart – find documentation from the physician
or pacemaker clinic for lead placement information
b. Asking the patient or looking at his/her wallet card (if available)
c. Checking a recent chest-x-ray for lead placement
Dual Chamber pacing
when a patient has an atrial and ventricular pacemaker
Pacing modes are determined by a sequence of letters.
1st letter: indicates which chamber will be “paced”
2nd letter: indicates which chamber is “sensed” by the pacemaker
3rd letter: pacemakers response to sensing the patient’s natural heart activity
AOO
This pacemaker mode paces in the atria 100% of the time; it has NO sensing capability
1. Post-op cardiac surgery in the presence of A-V block, especially after valvular surgery (due to the operative site being close to the AV node and bundle of His)
AAI
This pacemaker mode paces the atria, senses natural atrial activity, and inhibits pacing if natural activity occurs
1. Sinus node dysfunction with good AV function (i.e. sinus bradycardia, sinus arrest, sinoatrial block)
2. Atrial arrhythmias suppressed by chronic atrial pacing (i.e. atrial fibrillation with
slow ventricular response)
- Erratic impulses from ectopic atrial sites
- No discernible P wave (“squiggles”)
- R-waves not regular
Atrial Fibrillation
- Classic “sawtooth” pattern
- Ventricular rate may be regular or irregular depending on how many flutter waves are conducted through AV node
Atrial Flutter
- Atria activated by ectopic site instead of SA
- Different shaped P wave
- Early P in T wave (double hump)
Premature Atrial Contraction
SVT
- 150-250 bpm
- ectopic focus in atria
- Paroxysmal (PSVT): rhythm starts then stops
Atrial tachycardia
- Rapid rhythm 150-250 bpm
- Ectopic focus in atria
- 1:1 conduction (ventricle responds to every atrial impulse)
varies with respirations
sinus arrhythmia
sinus arrest
(sinus pause)
- SA node fails to fire
- HR normal or slow
- caused by vagal, hiccups
Inverted P wave/ no P wave/ after QRS P wave
Premature Junctional Contraction
AV node takes over as primary pacemaker
- 40-60 bpm
- P-wave: absent, inverted, or burried
Junctional Rhythm
AV node takes over as primary pacemaker
- 60-100 bpm
- NO or inverted P wave
Accelerated junctional rhythm
AV node takes over as primary pacemaker
- rate over 100 bpm
- NO or inverted P wave
Junctional tachycardia
An IVR of less than 20 is
an agonal rhythm
An IVR of 41 to 100 BPM is
an accelerated idioventricular rhythm
A ventricular rhythm with a rate of 20-40 bpm.
ventricular Escape Rhythm
