EKG book week 1 Flashcards
The vertical axis measures voltage. The distance along one small square represents ______ mV, and along one large square, ______ mV.
0.1; 0.5
What structure slows conduction between the atria and ventricles?
AV node
List the parts of the QRS complex
1) If the first deflection is downward, that part of the QRS complex is
called a Q wave.
2) The first upward deflection is called an R wave.
3) If there is a second upward deflection, it is called R′ (“R-prime”).
4) The first downward deflection following an upward deflection is called an S wave. Therefore, if the first wave of the complex is an R wave, the ensuing downward deflection is called an S wave, not a Q wave. A downward deflection can only be called a Q wave if it is the first wave of the complex. Any other downward deflection is called
an S wave.
5) If the entire configuration consists solely of one downward deflection, the wave is called a QS wave.
The initial part of the QRS complex represents ________
depolarization
septal
Ventricular repolarization inscribes a third wave on the EKG, the _____ wave.
T
What differentiates a segment from an interval?
A segment is a straight line connecting two waves, whereas an interval encompasses at least one wave plus, in most instances, the connecting straight line.
Each cycle of cardiac contraction and relaxation is initiated by spontaneous depolarization of the sinus node. Is this seen on an EKG, and if so, how?
(from recap on pg 47 of pdf)
It’s not seen
The effects of repolarization on the EKG are similar to those of
depolarization, except that the charges are reversed. Explain
A wave of repolarization moving toward a positive electrode inscribes a negative
deflection on the EKG. A wave of repolarization moving away from a positive electrode produces a positive deflection on the EKG.
A perpendicular wave produces a biphasic wave; however, the negative deflection of the biphasic wave now precedes the positive deflection.
