EKG Flashcards
(38 cards)
AUTOMATICITY
creation of impulse
EXCITABILITY
response to impulse
CONDUCTIVITY
passing of impulse
CONTRACTILITY
contraction + work of heart
CONDUCTION PATHWAY
SA (sinoatrial) NODE > INTERNODAL TRACT > RT/LT ATRIA > AV (atrioventricular) NODE > BUNDLE OF HIS > BUNDLE BRANCHES > PURKINJE FIBERS > VENTRICLE
how many BPM if SA node is controlling it?
60-100 BPM; normal sinus rhythm
how many BPM if AV node is controlling it?
40-60 BMP
how many BPM if BOH is controlling it?
20-40 BMP
what is the P WAVE responsible for?
atrial contraction/depolarization ; the electrical impulse into atria
what is the PR INTERVAL?
time from atrial depolarization to ventricular contraction (goes from start of P to start of R)
what is the QRS complex?
ventricular contraction/depolarization
what is the ST segment?
beginning of ventricular depolarization (from end of S to beginning of T)
what is the T WAVE?
ventricular repolarization (ending wave); heart is in diastole > rest
what is the QT INTERVAL?
entire depolarization and repolarization of the ventricles
EKG measurements: PR INTERVAL
0.12-.20 seconds - normal
EKG measurements: QRS COMPLEX
0.04-0.12 seconds - normal
EKG measurements: ST SEGMENT
0.12 seconds - normal (ensure there isn’t a 1mm+ height = MI)
EKG measurements: QT INTERVAL
0.34-0.43 seconds - normal
how many seconds is obtained to read an EKG?
SIX SECONDS; 6 SECONDS
how many small squares is a 6 second interval?
150 small squares = 6 seconds
how many large squares is a 6 second interval?
30 large squares = 6 seconds
how many small squares is equal to ONE MINUTE on EKG?
1500 small squares = 1 minute
how many large squares is equal to ONE MINUTE on EKG?
300 large squares = 1 minute
how do you figure out the heartrate on the EKG strip?
#1: obtain 6 second sample: 30 large squares OR 150 small squares #2: count the R intervals (intervals between QRS complex) #3: multiply this number by 10 (7 R intervals x10 = 70 BPM)