Ch. 35: cardiac monitoring, rhythm recognition Flashcards
What does a polarized state mean?
-cell is at rest
-negative charge
What does depolarization mean?
-inside of cell is positive
-contraction
What does repolarization mean?
slow movement of ions across the membrane restores the cell to the polarized states
What does the P wave represent?
time for passage of electrical impulse thru the atrium causing ATRIAL DEPOLARIZATION (contraction)
What does the PR interval represent?
time for impulse to spread thru atria, AV node, and bundle of His and Purkinje fibers to a point immediately preceding ventricular contraction
What does the QRS complex represent?
It represents the time taken for depolarization (contraction) of both ventricles (systole)
How many large boxes represents 1 second on an EKG strip?
5
What does one small square represent vertically?
0.1 millivolt
How do you calculate the atrial rate with the 10-times method?
1) get a 6 second strip
2) count # of p waves
3) multiply by 10
How do you calculate the atrial rate with the 10-times method?
1) get a 6-second strip
2) count # of p waves
3) multiply by 10
How do you calculate the ventricular rate with the 10-times method?
1) get a 6-second strip
2) count # of r waves
3) multiply by 10
How long should a P wave last?
0.06-0.12 sec
How long should a PR interval last?
0.12-0.20 sec
How long should a QRS complex last?
0.06-0.12 sec
How long should a ST segment last?
0.12 sec
How long should a QT interval last?
0.34-0.43 sec
How long should a T wave last?
0.16 sec
What is a normal sinus rhythm?
-starts in sinus node and progresses to ventricles through a normal conduction pathway
-sinus node > atria > AV node> bundle of His > bundle branches > Purkinje fibers