ECG Interpretation Flashcards
What are the three electric properties of the heart?
Automaticity: Ability to discharge impulses without stimulation from the nervous system
Conductivity: Spreads impulses rapidly to other cells
Rhythmicity: Regularity of activity
What does ECG monitoring reflect?
the electrical activity that immediately precedes mechanical activity
What are the pacemakers of the heart?
SA Node: 60-100 bpm
AV Node: 40-60 bpm
Purkinje Fibers: 20-40 bpm
What happens during the P wave?
Arterial depolarization
End of Diastole
What happens during the QRS complex?
Ventricular depolarization
Mitral valve closes -> aortic valve opens/beginning of systole
What happens during the T wave?
Ventricular repolarization
Aortic valve closes -> Mitral valve opens/End of Systole
What are leads?
Leads refer to both views and wires/electrodes attached to the patient
12 lead configuration, where limb leads II and I have the electrical activity of the heart going towards it
What is telemetry used for?
Monitoring (commonly used in hospitals)
3-5 leads
ECG box and seconds
One little box = 1 mm and .04 seconds
Five little boxes = One large box = 5 mm and .2 seconds
Five large boxes = 25 mm and one second
What is the triplet method?
Find the R on a large square, find the next R — for evert large square that passes count “300, 150, 75, 60, 50” to estimate HR
What is the six second method?
Every vertical line above the square is 3 sec — Use three lines, making 6 secs and count the R’s that are within to estimate HR (6=60, 8=80)
Sinus Bradycardia
Rate < 60 bpm
All other sections normal
Sinus Tachycardia
Rate > 100 bpm
All other sections normal
Name that rhythm
Premature Atrial Contraction (PAC)
Rate: underlying rhythm, irregular at PAC
Rhythm: irregular
P waves: one for every QRS, but PAC is different
Name that rhythm
Atrial Flutter
Rate: ventricular 120–150 bpm/atrial 250–300 bpm
Rhythm: regularly irregular
P waves: flutter waves (saw tooth)
PR interval: non-identifiable
Name that rhythm
Atrial Fibrillation
Rate: varies, uncontrolled: over 100 bpm
Rhythm: irregularly irregular
P-Waves: absent- fibrillatory waves
PR interval: absent
Name that rhythm
Atrial Fibrillation
Rate: varies, uncontrolled: over 100 bpm
Rhythm: irregularly irregular
P-Waves: absent- fibrillatory waves
PR interval: absent
Name that rhythm
Premature Ventricular Contraction — Trigeminy
Rate: underlying rhythm
Rhythm: irregular
P waves: one for every QRS, but absent at premature ventricular contraction (PVC)
PR interval: underlying, absent at PVC
QRS complex: underlying, wide and bizarre at PVC
Name those rhythms
Couplets and Runs
Name that rhythm
Ventricular Tachycardia
Rate: 100–250 bpm
Rhythm: regular
P waves: absent
PR interval: absent
QRS complex: wide and bizarre
Can be stable or unstable
Name that rhythm
Ventricular Fibrillation
Rate: absent
Rhythm: absent
P waves: absent
PR interval: absent
QRS complex: absent
Fatal if not treated immediately: defibrillation
Name that rhythm
First-Degree Heart Block
Lengthening of the PR interval (over 0.20 sec)
Rate/rhythm depend on underlying rhythm
P waves and QRS are normal
Generally asymptomatic and not treated
Name that rhythm
Second-Degree (Type I) HB
Wenckebach’s/Mobitz type I
Progressive lengthening of PR interval until a QRS complex is dropped
Cycle repeats
longer, longer with a drop — that’s what we ca wenckebach
Name that rhythm
Second-Degree (Type II) HB
Mobitz type II
Consistent drop of a QRS complexes
Often multiple P waves for one QRS
Name that rhythm
Third-Degree (Complete) HB
No conduction between atria and ventricles
Atrial rate and ventricular rate are separate QRS over .12 seconds
Requires pacemaker
