ECG Flashcards
What won’t an ECG tell you?
CO, hemodynamic status, pulse
What is a positive deflection?
impulse is heading toward the recording electrode
How do you place 3-lead electrodes?
white on right, smoke over fire (black over red on left)
What does each tiny box represent?
0.04 seconds
What does each larger box represent?
0.2 seconds
What is P wave representing?
atrial depolarization
What is QRS complex representing?
ventricular depolarization
What is T wave representing?
ventricular repolarization
What are the steps to reach ECG?
- rhythm
- rate
- waves
- intervals
- axis
- hypertrophy
- ST changers
- blocks
What is normal intrinsic rate from SA node?
60-100 bpm
What is normal intrinsic rate from AV node?
40-60 bpm
What is normal intrinsic rate from ventricular?
20-40 bpm
What is a normal P wave length and amplitude?
less than 0.12 sec and less than 2 mm
What is a normal QRS interval?
<0.12 seconds
What is a normal PR interval?
0.12 to 0.2 s
What does a short QT interval indicate?
increased Ca and Mg
What does a long QT interval indicate?
dec Ca, Mg or MI
What does a longer QRS interval indicate?
BBB, V fib or hyperkalemia
Positive Deflection
Impulse headed toward recording electrode
Negative Deflection
Impulse headed away from recording electrode
Small box length
0.04 seconds, 1mm
Large box length
0.2 seconds
P wave represents
Atrial depolarization
QRS represents
Ventricular depolarization
T wave
Ventricular repolarization
Normal Sinus Rhythm
Rate: 60-99 Rhythm: regular P waves: present P-R interval: 0.12-0.20 seconds QRS complex: <0.12 seconds
Sinus Tachycardia
Rate: >100 Rhythm: regular P waves: present P-R interval: 0.12-0.20 seconds QRS complex: <0.12 seconds
Sinus Bradycardia
Rate: <60 Rhythm: regular P waves: present P-R interval: 0.12-0.20 seconds QRS complex: <0.12 seconds Why: meds, athletes
Sinus Arrhythmia
Rate: 60-100 Rhythm: regularly irregular P waves: present P-R interval: 0.12-0.20 seconds QRS complex: <0.12 seconds
Junctional Escape Rhythm
Rate: 40-60 Rhythm: regular P waves: none P-R interval: N/A QRS complex: <0.12 seconds
Ventricular Escape Rhythm
Rate: 20-40 Rhythm: regular P waves: none P-R interval: N/A QRS complex: >0.12 seconds Ventricles beat at own pace (not paced by SA or AV)
Premature Atrial Contractions (PACs)
Rate: 60-100 Rhythm: irregularly irregular P waves: present (can’t always be seen) P-R interval: 0.12-0.2 seconds QRS complex: <0.12 seconds Why: increased epinephrine, caffeine, cocaine, hyperthyroidism
Premature Ventricular Contraction
Rate: any
Rhythm: irregular
P waves: none
P-R interval: N/A
QRS complex: <0.12 seconds in normal QRS but PVC is wider
Why: Low O2 levels, hypokalemia, injury to heart muscle, MI
3+ in a row is ventricular tachycardia
Supraventricular Tachycardia (SVT)
Rate: >150-180 Rhythm: regular P waves: present (may not be visible) P-R interval: normal if visible QRS complex: <0.12 seconds
Ventricular Tachycardia
Rate: >100 Rhythm: regular P waves: none visible P-R interval: N/A QRS complex: >0.12 seconds Why: heart disease, MI scar
Torsades de Pointes
Rate: >100 (usually 250-350) Rhythm: regular P waves: none P-R interval: N/A QRS complex: >0.12 seconds Causes: hypokalemia, hypomagnesemia, hypocalcemia, meds
Atrial Flutter
Rate: 250-360 Rhythm: regular P waves: sawtooth waves P-R interval: N/A QRS complex: <0.12 seconds