EKG KAISER EXAM REVIEW
QUESTIONS WITH COMPLETE
ANSWERS
Cardiac Conduction Pathway System - Answer-SA node> AV node> Bundle of His> Left
and Right bundle branches> Purkinjie fibers
Pacemakers of the heart - Answer-♥ Natural: SA Node = 60-100 beats/minute
♥ Backup: AV Node = 40-60 beats/minute
♥ Backup: Purkinje Fibers (ventricles) = 20-40 beats/minute
SA Node - Answer-• Intrinsic Pacemaker of the heart
• Rate 60-100 beats/min
• RA (Right Atrium), close to SVC (Superior Vena Cava)
• Blood supply from RCA (Right Coronary Artery) & LCA (Left Coronary Artery)
Interatrial/Internodal Tracts - Answer-Transmits impulses from the SA node to the AV
node through the RA & LA
AV node - Answer-• Slows conduction (40-60 beats/min)
• Physiologic delay allows atrial kick on floor of RA near tricuspid valve
Bundle of His - Answer-Bundle of cardiac muscle fibers that conducts the electrical
impulses from the AV node in the right atrium to the septum between the ventricles and
then to the left and right ventricles.
bundle branches - Answer-Right and Left (Left anterior & Left posterior fascicles)
Purkinjie Fibers - Answer-Fibers from Bundle Branches imbedded into the ventricle
walls.
Depolarization vs Repolarization - Answer-Depolarization - electrical excitation of the
cell membrane, normally followed by mechanical contraction
Repolarization - return of cell membrane to its resting state, normally followed by
mechanical relaxation
Electrical and mechanical activity of the heart - Answer-♥ The heart has two activities
that are performed rhythmically: electrical activity followed by mechanical activity
♥ Electrical activity always precedes mechanical activity
♥ It is possible to have electrical activity without mechanical response
♥ Always check the patient - Do Not Depend on the Machine!!!
, Measurement of the boxes in the ekg - Answer-♥ A standard ECG is printed at 25mm
per second or 25 small squares per second. Since one second divided by 25 small
boxes, then each 1 mm box = 0.04 seconds. The larger boxes indicated by the heavier
lines are equal to 0.20 seconds.
♥ Voltage is measured along the vertical axis and is expressed in millivolts (mV). The
standard calibration is that a 1 mV signal produces a 10-mm deflection (0.1 mV=1mm).
Simply put 10 small squares vertically is equal to 1 millivolt
EKG waveforms and intervals - Answer-♥ P wave - rounded with upright deflection in
lead II, atrial depolarization
♥ PR interval- delay @ AV junction
• measure from beginning of P wave to beginning of QRS
• Normal duration 0.12 - 0.20 seconds •
S wave - Negative deflection following the R-wave
♥ QRS complex - multiple components, Ventricular depolarization, - 0.06 -0.11
• Q wave - first negative deflection after P wave R wave
• Positive deflection after the Q
♥ J point - marks where the QRS complex ends and the ST segment begins
♥ ST segment - normally isoelectric line between QRS and the beginning of the T wave
♥ QT interval - beginning of the QRS complex to the end of the T wave; changes with
heart rate, usually half of the R to R interval. beginning of vent activation through
Ventricular depolarization. 0.44 -0.48 (Rate dependent)
♥ T wave - follows the QRS; typically, larger than the P wave and slightly asymmetric;
Ventricular repolarization
♥ U wave - not usually seen, may be due to hypokalemia or digitalis toxicity
Isoelectric Line -No perceived electrical current
indication of a flat line at any time in the duration of a series of waves - Answer-
indicates no electrical activity at that particular moment
Nursing Responsibilities when theres changes in ECG rhythm - Answer-♥ Print,
measure, interpret and post rhythm strips per unit standard.
♥ Get a 12 lead ECG for any rhythm changes.
♥ Get a set of vital signs for any rhythm changes.
♥ Know your unit standards and when to notify the MD.
Why is normal conduction and heart rate important? - Answer-critical for adequate filling
& optimum cardiac output (CO)
Mechanism of dysrhythmias: Altered Automaticity - Answer-change in rate of pacer
cells; sympathetic vs. parasympathetic
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller biggdreamer. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $15.49. You're not tied to anything after your purchase.