CCRN AACN Exam Questions with Correct
Answers
atrial fibrillation adverse consequences
1. decreased cardiac output due to loss of atrial kick, rapid ventricular rate, irregular
ventricular rhythm
2. tachycardia induced cardiomyopathy - in rapid afib for prolonged period of time
3. thromboembolism
right bundle branch
-right side of the interventricular septum and right ventricle
-impulse travels slower as the right ventricle is smaller/thinner
left bundle branch
two main divisions: anterior fascicle and posterior fascicle carrying impulses to the left
ventricle
PR interval
delay of AV node to allow filling of ventricles
QRS complex
ventricular depolarization
shape depends on the lead that is being monitored and the ventricular activation device
T wave
,ventricular repolarization
normally in the same direction as the QRS
upright, flat, inverted
pathologies of T wave
MI, E/L levels, drug effect, myocardial disease, and lead being recorded
u wave
repolarization of the purkinje fibers
SHOULD BE POSITIVE especially when T wave is positive
large u waves can be seen when repolarization is abnormally prolonged - E/L imbalances like
hypokalemia, hypocalcemia, hypomagnesemia, IICP, LVH, certain medications
ST segment
early ventricular repolarization
should be at isoelectric line
J point
where QRS complex ends and ST segment begins
QT interval
,ventricular depolarization and repolarization varies with age, gender, and heart rate
beginning of the QRS to the end of the T wave
QT must be corrected to a HR of 60 bpm
QTc
corrected QT interval =
QT/(square root of R-R interval)
normalizes for HR
long QTc --> torsades, ventricular arrhythmia, Vfib
vertical axis
each small box is 1mm or 0.1 mV
each large box is 5mm or 0.5 mV
most common complication of ischemic heart disease and MI
dysrhythmias
best leads for differentiating wide QRS rhythms
v1 and v6
v1 and v6
helps to differentiate VTACH from SVT with aberrant intraventricular conduction
, helps to recognize right and left bundle branch blocks
differentiates between right and left ventricular ectopy
differentiates between right and left ventricular pacing
v1 and v6 placement
v1 - fourth intercostal space at the right sternal border
v6 - left midaxillary line at the v4 level (fifth intercostal space midclavicular line)
primary dysrhythmia monitoring lead
V1
what is lead II used for?
used to identify atrial activity if unclear in other leads or for visualization of R waves during
synchronized cardioversion
rhythms with a short PR interval
may indicate presence of accessory pathway
lead III or avF
assists in diagnosis of hemiblock
allows identification of retrograde P waves
allows identification of atrial flutter waves
Answers
atrial fibrillation adverse consequences
1. decreased cardiac output due to loss of atrial kick, rapid ventricular rate, irregular
ventricular rhythm
2. tachycardia induced cardiomyopathy - in rapid afib for prolonged period of time
3. thromboembolism
right bundle branch
-right side of the interventricular septum and right ventricle
-impulse travels slower as the right ventricle is smaller/thinner
left bundle branch
two main divisions: anterior fascicle and posterior fascicle carrying impulses to the left
ventricle
PR interval
delay of AV node to allow filling of ventricles
QRS complex
ventricular depolarization
shape depends on the lead that is being monitored and the ventricular activation device
T wave
,ventricular repolarization
normally in the same direction as the QRS
upright, flat, inverted
pathologies of T wave
MI, E/L levels, drug effect, myocardial disease, and lead being recorded
u wave
repolarization of the purkinje fibers
SHOULD BE POSITIVE especially when T wave is positive
large u waves can be seen when repolarization is abnormally prolonged - E/L imbalances like
hypokalemia, hypocalcemia, hypomagnesemia, IICP, LVH, certain medications
ST segment
early ventricular repolarization
should be at isoelectric line
J point
where QRS complex ends and ST segment begins
QT interval
,ventricular depolarization and repolarization varies with age, gender, and heart rate
beginning of the QRS to the end of the T wave
QT must be corrected to a HR of 60 bpm
QTc
corrected QT interval =
QT/(square root of R-R interval)
normalizes for HR
long QTc --> torsades, ventricular arrhythmia, Vfib
vertical axis
each small box is 1mm or 0.1 mV
each large box is 5mm or 0.5 mV
most common complication of ischemic heart disease and MI
dysrhythmias
best leads for differentiating wide QRS rhythms
v1 and v6
v1 and v6
helps to differentiate VTACH from SVT with aberrant intraventricular conduction
, helps to recognize right and left bundle branch blocks
differentiates between right and left ventricular ectopy
differentiates between right and left ventricular pacing
v1 and v6 placement
v1 - fourth intercostal space at the right sternal border
v6 - left midaxillary line at the v4 level (fifth intercostal space midclavicular line)
primary dysrhythmia monitoring lead
V1
what is lead II used for?
used to identify atrial activity if unclear in other leads or for visualization of R waves during
synchronized cardioversion
rhythms with a short PR interval
may indicate presence of accessory pathway
lead III or avF
assists in diagnosis of hemiblock
allows identification of retrograde P waves
allows identification of atrial flutter waves
