EKG basics Flashcards
(26 cards)
quick cheat to confirm normal axis
up in 1 and avF
nl HR
60-100
1 small box time
0.04 sec or 40 msec
how many small boxes in a big box?
5
if reg rhythm, equation to calculate rate
300/# of large squares between consecutive R waves
normal axis
-30 to +90
PR interval
0.12-0.20 seconds (3-5 small squares)
A prolonged or changing (esp lengthening) PR interval indicates _________
heart block
QRS interval
normally less than 0.12 seconds (3 small squares)
widened QRS width indicates some sort of conduction defect with ____________________
the left or right bundle branches
what are we looking at with ST segments?
Look for sloping (especially downsloping) or flattening
The PR interval reflects ___
conduction through the AV node.
If PR interval is > 200 ms, what is present
first degree heart block
Consistently prolonged PR interval
first degree heart block
Progressilvely prolonged PR interval followed by dropped QRS
second degree heart block type I
We see shortened PR interval (<120 msec) in ______
Preexcitation syndromes AV nodal (junctional) rhythm
The presence of broad, notched (bifid) P waves in lead II is a sign of ______
left atrial enlargement, classically due to mitral stenosis.
The presence of tall, peaked P waves in lead II is a sign of ______
right atrial enlargement, usually due to pulmonary hypertension (e.g. cor pulmonale from chronic respiratory disease)
Anterior leads
V1, V2, V3, V4
Blood supply to anterior leads
LCA, LAD
Lateral leads
1, aVL, V5, V6
Blood supply to lateral leads
Circumflex
Septal leads
V1, V2
Blood supply to septal leads
LAD
