ECG basics Flashcards
Leads 1-3 are ______ leads
Limb
Leads aVR, aVL, aVF are _____ leads
Augmented limb
Leads V1-V2 view what part of the heart?
Septum
Leads V3-V4 view what part of the heart?
Anterior (front) wall of the left ventricle
Leads V5-V6 view what part of the heart?
Lateral (side) wall of the left ventricle
aVL Lead views what part of the heart?
Lateral surface of the left ventricle
aVF Lead views what part of the heart?
Inferior surface of the left ventricle
Lead 1 views what part of the heart?
Lateral surface of the LV
Lead 2 views what part of the heart?
Inferior surface of the LV
ECG paper, 1 small/big box = seconds
Small: 0.04 seconds
Big: 0.20 seconds
What two leads are reflections
Leads 2 & aVR
P wave: happening, time, amp
Atrial depolarization, <0.11 sec, <2.5 mm
Time AV node delays impulse, ECG segment
0.12-0.20 seconds
PR interval
QRS complex: happening, time,
Ventricular depolarization
0.11 seconds
Q wave: happening, time, amp
Conduction through intraventricular septum
< or equal 0.04 seconds
< or equal 1/3 overall hight
Negative deflection
R wave
Positive deflection after Q wave
Ventricular depolarization
S wave
Any negative deflection after R wave
Ventricular depolarization
J point
Where QRS segment ends and ST segment begins
End depolarization, start Repolarization
ST segment, happening, elevated vs depressed
Early ventricular repolarization
Elevated - myocardial injury
Depressed - ischemia
T wave, happening, amp
Ventricular Repolarization
Half overall QRS hight & oriented same direction
Two halves of T wave
First half represents absolute refractory period (ARP)
Second half represents relative refractory period (RRP)
Tall, pointed T waves
Depressed ST segment
Hyperkalemia
Deep, inverted T waves,
Acute CNS event (ex intracranial hemorrhage, stroke)
Dulled u + n waves (T wave)
Hypokalemia or cardiomyopathy
QT interval: happening, time
Ventricular depolarization and Repolarization
0.39 sec to 0.46 sec
Ectopic
Impulse/rhythm that originated from a site other than the SA node
