EKGs Flashcards
(22 cards)
Heart Rate
1 small box: .04 sec: 1mm 1 large box: .2 sec
How to determine rate (regular rhythm)
Count QRS complexes in 30 large boxes (6 sec) and multiply by 10 Count QRS on whole strip (10 sec) and multiply by 6 Can also use 60 Divided by the space between QRS complexes (R) or between P waves Rough estimate would be to divide 300 by the number of Large boxes between two QRS complexes
Where do you measure the heart rate intervals?
The frontal leads (I, II, III, aVF, aVL, aVR)
What is the initial downward reflection?
Q wave
What are negative deflections after the first one?
S waves
What is the positive deflection?
R wave
How can two R waves be present?
There must be a S wave between them
How can two S waves be present?
There must be an R wave between them
Lead I see?
Lateral view of heart
Lead II sees?
The apex of the heart
Lead III sees
The inferior right aspect of heart (usually perpendicular to the septum)
Lead aVF
Inferior aspect of heart
Lead aVR
(weird one) also looks at apical region of heart
Lead aVL
Looks at
What is the usual first step in reading an EKG?
Looks at the QRS Duration - Normal is <.12msec (3 small boxes)
What do you read after finding the QRS interval?
You determine the PR interval
What is the normal PR interval?
Normal is .12-.2 sec
What will you see in WPW syndrome?
A QRS duration longer than .12 sec and a PR interval less than .12 sec Delta Waves: Slow slurred upstrokes to QRS complex Secondary ST and T wave changes (due to abnormal repolarization Kent bundles (bundles that bypass the AV node
What will you consider if the PR interval is >.12 (normal), but the QRS is >.12?
If see a terminal R V1: RBBB If see midQRS notches in R waves: LBBB Non specific LVCD
What do you look for after determining the normal duration of intervals?
Find the axis of the QRS complex
What is the consequence of WPW syndrome?
It makes reading EKGs for other diseases unreliable (STOP analysis) Makes people susceptible to Supraventricular tachycardia also
