Basic ECG Flashcards
What is the inherent pacemaker of the heart?
SA node.
At a rate of 60-100
Any cell in the heart an initiate an impulse.
The fastest pacer will always control the pace of the heart.
SA node may be working fine, but it may not be the fastest.
What does the P wave indicate?
All P waves must be?
Atrial depolarization (does not tell about contraction)
Identical in size, shape, and position (this is what distinguishes from a U wave)
What does the QRS wave indicate?
Ventricular depolarization
What does the T wave indicate?
Ventricular repolarization
What is the appropriate time measurement for the PR interval?
.12 - .2 sec.
What is the appropriate time measurement for the QRS interval?
less than .12 seconds
What is the time measurement for one SMALL box on the EKG paper?
.04 sec
What is the time measurement of one LARGE box on the EKG paper?
.20 sec
How do you calculate heart rate?
Take a pulse
Rapid rate calculation
Precise rate calculation
What are the RULES for Normal Sinus Rhythm?
Determine the regularity of R waves Calculate the heart rate Identify and examine P waves Measure the PR Interval Measure the QRS complex
Important Measurements
PR interval - .12 - .20 sec.
QRS complex – less than .10 seconds
P – P – Regular
R – R - Regular
Analyzing a Rhythm StripStep – by - step
Determine the regularity of R waves Calculate the heart rate Identify and examine P waves Measure the PR Interval Measure the QRS complex
Calculate the heart rate
Rapid rate calculation-
Count the number of R waves in a 6 sec strip
Multiply by 10
Do not include premature beats in calculating
Precise rate calculation-
Count the number of small squares between two consecutive R waves
Divide the number of small squares into 1500 or use a conversion chart
Only accurate for REGULAR RHYTHMS
Identify and Examine P waves
One P wave preceding each QRS
All P waves identical in shape, size, and position
P to P interval should be regular
Examine the ST Segment
Normal ST segment is:
Elevation or depression measuring ____ above or below is abnormal
Elevation =
Depression =
flat and at the isoelectric line
1mm
acute myocardial injury
myocardial ischemia, hypokalemia, digitalis