EKG stuff- Exam 2 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 V1
Up to 2.5mm amplitude
< .12 secs / 3 small boxes
The presence of broad, notched (bifid) P waves in
lead 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 wave
Site of origin lower or from AV junction =________ P
wave
upright
inverted
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 ventricular
depolarization – time from the AV node through the Purkinjie fibers.
QRS Complex
TRUE OR FALSE
The QRS Complex may or may not be composed of
three individual waves (Q, R, S)
TRUE
Where does the QRS Complex begin and end?
Begins where first wave complex deviates from baseline Ends where last wave of complex flattens at, above, or below the baseline
What should a normal QRS complex look like? Normal amplitude? Normal duration?
• Should be narrow and sharply 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/or
Wider 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 wave
ventricular activation
The ___ Wave is the negative deflection following the R wave, which represents _________.
S wave
Represents ventricular depolarization
The __ ______ is from the end of the QRS
complex to the beginning of the T wave and represents ___________________.
ST interval
the time between ventricular depolarization to
repolarization
The point where the QRS complex ends and the ST
segment begins is the ____________. This point represents the end of ventricular depolarization.
J point (May not be evident or May indicate early repolarization, ischemia/infarction, or pericarditis)
ELEVATION of the ST segment (greater than 2 small boxes) can mean several things including ___________.
Infarction
Pericarditis – diffuse elevation in all/most leads
Early repolarization
DEPRESSION of the ST segment (greater than 2 small boxes) can mean several things including ___________.
- Ischemia
* After Digitalis administration (ionotropic med given to some CHF pts)
The __ Wave represents ventricular repolarization.
T wave
TRUE OR FALSE? The T wave should only be above the isoelectric line.
FALSE. The T wave can be above or below the isoelectric line.
What do we look for in a normal T wave? What about duration/amplitude?
Normal T waves should be Slightly rounded and slightly asymmetrical.
We do not measure T waves, we are only concerned if they are “inverted” or “peaked”.
Why would you be concerned about an inverted T wave?
Inverted T waves may suggest cardiac ischemia,
left ventricular hypertrophy, CNS injury, Digitalis
administration, and hypokalemia
TRUE OR FALSE.
T wave amplitude more than half the height of QRS
complex (peaked T wave) may indicate
myocardial ischemia or hyperkalemia.
TRUE.
However, this is not common.
The QT interval begins at the onset of ______ and ends at the end of ________.
QRS
T wave
The QT interval represents ___________ and _____________.
Ventricular depolarization and repolarization
How long does a normal QT interval last?
Normal 0.33 sec - 0.47 sec
A QT interval greater than ____ is always abnormal!!
500
In the QT interval, Prolonged and shortened both increase risk of _________ __________.
ventricular tachycardia - Torsades
Prolonged QT can be genetic or caused by
___________________________.
Shortening of QT can by due to _____________.
prolonged- medications, hypothyroidism, hypocalcemia
shortened- hypercalcemia
The __ Wave is not always present, but is most often seen in young athletes or bradycardia.
U Wave
If the U wave is large, may represent _________, __________ or _____________.
hypokalemia, thyroid disease, medication effect
The U wave is thought to represent repolarization of the ______ ______.
papillary muscles/ Purkenje Fibers
The R-R interval is used to measure ____________.
the regularity of the rhythm
same throughout= regular rhythm
How would you calculate an approximate heartrate on an EKG using the 6-second methond?
Count number of QRS complexes in a 6-second
interval and multiply number by 10
To calculate a heartrate on an EKG using the Triplicate method, you would do what?
Start at a QRS (preferably on dark line, to help you see it, but if no R hits dark line you can start on any line) and count over 5 boxes, beginning at 300 on first line, then 150, then 100, then 75, 60, 50, stopping at next QRS. Where this QRS falls gives you the heartrate.
When determining the AXIS of an EKG, Imagine that your left thumb is ______ and right thumb is ____, then look at the QRS complexes in those leads, if majority are positive, thumb is ___, if majority are negative, thumb is _____.
If both thumbs are up, the axis is ________. If right thumb up, but left thumb is down, the EKG has __________. If left thumb is up, but right thumb is down, the EKG has _________. If both thumbs are down, this is an ____________ axis.
Lead I (left) aVF (right)
up
down
normal
right axis deviation (RAD)
left axis deviation (LAD)
indeterminate
If you have an indeterminate axis, you would then refer to which lead?
If lead II is positive, you would have a ______ axis.
If lead II is negative, you would have a ______ axis deviation.
Lead II
Normal
Left
What might an indeterminate axis indicate?
emphysema, hyperkalemia, improper lead placement
What types of disorders could a LAD be indicative of?
What about a RAD?
LAD: left ventricular hypertrophy (LVH), emphysema,
hyperkalemia, ASD (atrial septal defect), obesity
RAD: RVH (right ventricular hypertrophy), chronic lung dz, PE
(**left usu cardiac issues, right usu lung issues)
A _____ axis deviation can be normal in kids and tall thin adults
right
What would you call a heart RHYTHM that has patterned irregularity or “group beating“?
Regularly Irregular
What would you call a heart RHYTHM that has only one or two R-R intervals are unequal to the others?
Occasionally irregular
common in PAC’s or PVC’s
What would you call a heart RHYTHM that has totally irregularity; no relationship between R-R intervals? What condition is this rhythm usually indicative of?
Irregularly irregular
AFIB
What would you evaluate the P wave for when interpreting an EKG ?
peaked, absent, inverted, biphasic
Is there one P wave before every QRS? One QRS for
every P?
Normal duration? <0.12sec
Are P waves present and uniform in appearance?
What would you evaluate the PR interval for when interpreting an EKG ?
shortened or prolonged
Is the PR interval within normal limits?
Is the PR interval normal? 0.12 - 0.20sec
Is the PR interval constant or does is vary?
(Dont measure just one-measure multiple in running lead!)
What would you evaluate the Q wave for when interpreting an EKG ?
Abnormally deep? Should be less than 2 boxes in
amplitude and 1 box in duration
What would you evaluate the QT interval for when interpreting an EKG ?
short or prolonged?
Duration? (Also varies by source) 0.33-0.47 sec
What would you evaluate the R wave for when interpreting an EKG ?
tall? look at QRS complex- wide?
Do they all look the same and normal?
What would you evaluate the ST segment for when interpreting an EKG ?
elevation or depression
What would you evaluate the T wave for when interpreting an EKG ?
Upright or inverted?
Peaked or flat?
U wave?
What would you evaluate the QRS Complex for when interpreting an EKG ?
Is the QRS duration normal?
• Duration tends to vary by source, < 0.12sec
• >0.12 second (wide), something is slowing the electrical current through the ventricles (Purkinje fibers)
• Do the QRS’s look alike?
How could you tell someone has LEFT VENTRICULAR HYPERTROPHY by looking at their EKG?
S in V1 or V2 (whichever is bigger) ≥ 30 mm (6 large boxes)
-OR
R in V5 or V6 ≥ 35 mm (7 large boxes)
