Part 1: EKG Basics Flashcards
How if voltage measured
1 small box = 0.1mV
Inferior leads
II, III, aVF
Anterior leads
V1, V2, V3
Posterior leads
V1, V2 (inverted view)
Lateral (left) leads
I, aVL, V4-V6
Right leads
aVR, V1
Normal P-wave measurements
<0.25mV
<120msec
Normal PR interval
120-200msec
QRS duration
<120msec
Normal QTc
250-450msec
How to determine axis via isoelectric lead
90 from isoelectric, then look at aVF to determine positive or negative
What is isoelectric in multiple leads?
then indeterminate axis
Look for atrial enlargement in which leads
II, V1
Why V1 in atrial enlargement?
biphasic, able to tell which is hypertrophied
Atrial enlargement measurements
right: >25mV
left: more than 120msec
Right ventricle enlargement signs
right axis deviation
early R wave progression
LVH criteria
R wave in aVL >11mm OR
S in V1 or V2 + R in V5 or V6 >35mm
Ventricular strain pattern
inverted T-waves or asymmetric ST-depressions
in areas over where problem is–often precordial leads
