EKG II Flashcards
The __________ node is the primary pacemaker of the heart and is located in the upper right atrium.
Sinoatrial (SA) node
The ________ node slows impulses and backs up the pacemaker. It is located in the lower right atrium.
Atrioventricular (AV) node
The ________ ___ ____ goes from the AV node through the ventricular septum.
Bundle of His
The “baseline” of an EKG, from which all defections take off from is called the ______________.
Isoelectric line
The P wave represents what?
atrial depolarization, contraction of both atria
True or False? Sinus means “normal”.
FALSE. Sinus means that the SA node is properly initiating the beat
What should normal P waves look like?Normal Amplitude? Normal Length?
Smooth, round, and usually upright EXCEPT- may be inverted on aVR or V1Up to 2.5mm amplitude< .12 secs / 3 small boxes
The presence of broad, notched (bifid) P waves inlead II or V1 is a sign of ____ ______ ___________.
Left atrial enlargement
The presence of peaked P waves (high amplitude)in leads II and V1 is indicative of ______ ______ ___________.
Right atrial enlargement(caused by pulmonary HTN or chronic lung disease)
If a pt’s EKG shows different/ asymmetrical P waves, it usually indicates what?
That the SA node is not firing correctly and is likely firing from different spots
P waves that do not originate from the SA node are called _________ P Waves and can be positive or negative.
Ectopic
Site of origin high in atria = ________ P waveSite of origin lower or from AV junction =________ Pwave
uprightinverted
The __ interval represents atrial depolarization through the onset of ventricular depolarization or REST.
PR interval
The PR interval is measured from beginning of ________ to onset of ____________.
P Wave QRS complex
What is the normal duration of a PR interval?
< 0.20 secs
The _____ _________ Represents ventriculardepolarization – time from the AV node through the Purkinjie fibers.
QRS Complex
TRUE OR FALSEThe QRS Complex may or may not be composed ofthree individual waves (Q, R, S)
TRUE
Where does the QRS Complex begin and end?
Begins where first wave complexdeviates from baselineEnds where last wave of complexflattens at, above, or below thebaseline
What should a normal QRS complex look like? Normal amplitude? Normal duration?
• Should be narrow andsharply pointed• Amplitude varies from<5 mm to >15 mm• Less than 0.12 sec
The __ Wave is the first NEGATIVE deflection of the QRS Complex
Q wave(If theres no negative deflection then theres no Q wave)
What is the normal amplitude and normal duration of a Q wave?
Should be less than 2 boxes in amplitude and 1 box in duration
A Q wave is considered pathological if it is what?
Deeper than 2 small squares (0.2mV) and/orWider than 1 small square (0.04s)
What might a pathological Q wave indicate for a patient?
Past or current MI
The __ Wave is the first POSITIVE deflection in the QRS complex and arises from ___________.
R waveventricular activation
The ___ Wave is the negative deflection following the R wave, which represents _________.
S wave Represents ventricular depolarization