ADVANCED – DYSRHYTHMIAS EXAM
REVIEW QUESTIONS AND ANSWERS
Excitability - Answer-the ability of non-pacemaker heart cells to respond to an electrical
impulse that begins in pacemaker cells.
Depolarization - Answer-occurs when the normally negatively charged cells within the
heart muscle develop a positive charge.
Conductivity - Answer-the ability to send an electrical stimulus from cell membrane to
cell membrane. As a result, excitable cells depolarize in rapid succession from cell to
cell until all cells have depolarized. Ex: the wave of depolarization causes the
deflections in the ECG waveforms that are recognized as the P wave and QRS
complex.
Contractility - Answer-the ability of atrial and ventricular muscle cells to shorten their
fiber length in response to electrical stimulation, causing sufficient pressure to push
blood forward through the heart. In other words, this is the mechanical activity of the
heart.
AV Node - Answer-where impulses slow down or are delayed before proceeding to the
ventricles. This delay is reflected in the PR segment on the ECG. This slow conduction
provides a short delay, allowing the atria to contract and the ventricles to fill.
SA Node - Answer-the heart's primary pacemaker. It can spontaneously and
rhythmically generate electrical impulses at a rate of 60-100 beats per min and therefore
has the greatest degree of automaticity.
Purkinje Cells - Answer-composed of the bundle of HIS, bundle branches, and these
fibers. Responsible for the rapid conduction of electrical impulses throughout the
ventricles, leading to ventricular depolarization and the subsequent ventricular muscle
contraction.
Semi-Reclined - Answer-While obtaining a 12-lead ECG, remind the patient be as as
still as possible in a ________________________ position, breathing normally.
Clea, Dry, Moist - Answer-For continous ECG monitoring, be sure to
__________________ skin and clip hairs/shave. Ensure that the electrode placement is
_____________ and the gel on each electrode is ______________ and fresh.
P Wave - Answer-a deflection on an ECG representing atrial depolarization. When the
electrical impulse is consistently generated form the SA node, this wave has a
consistent shape in a given lead. If an impulse is then generated from a different
(ectopic) focus, such as atrial tissue, the shape of this wave changes in the lead,
indicating that an ectopic focus has fired.
, PR Segment - Answer-the isoelectric line from the end of the P wave to the beginning of
the QRS complex, when the electrical impulse is traveling through the AV node, where it
is delayed.
PR Interval - Answer-measured form the beginning of the P wave to the end of the PR
segment. Represents the time required for atrial depolarization, the impulse delay in the
AV node, and the travel time to the Purkinje files. Normally measures from 0.12-0.20
seconds (five small blocks).
QRS Complex - Answer-represents ventricular depolarization on ECG lead.
ST Segment - Answer-an isoelectric line and represents early ventricular repolarization.
Changes may be a result of myocardial injury, ischemia, infarction, conduction
abnormalities or medications.
T wave - Answer-ventricular repolarization, usually positive, rounded, and slightly
asymmetric. May change as a result of myocardial ischemia, potassium/calcium
imbalances, medications, or ANS effects.
U wave - Answer-if this is present, it follows the T wave a may result from slow
depolarization of ventricular Purkinje fibers. An abnormal U wave may suggest an
electrolyte abnormality (Hypokalemia).
QT Interval - Answer-represent the total time required for ventricular depolarization and
depolarization. Measured from the beginning of the Q wave to the end of the T wave.
Varies with the patient's age and gender and changes with the heart rate, lengthening
with slower heart rates and shortening with faster rates.
Artifact - Answer-an interference seen on the monitor or rhythm strip, which may look
like a wandering or fuzzy baseline. It can be caused by patient movements, loose or
defective electrodes, improper grounding, or faulty ECG equipment such as broken
worse or cables. Some can mimic lethal dysrhythmias such as ventricular tachycardia or
ventricular fibrillation. ASSESS PATIENT TO DIFFERENTIATE ARTIFACT FROM
ACTUAL LETHAL RHYTHMS. DO NOT RELY ONLY ON THE ECG MONITOR.
Normal Sinus Rhythm - Answer-the rhythm originating from the SA node that meets
these ECG criteria:
-Rate: 60-100bpm
-Rhythm: atrial and ventricular rhythms regular
-P waves: present, consistent configuration, one P wave before each QRS complex
-PR Interval: 0.12-0.20 seconds and constant
-QRS Duration: 0.04-0.10 second and constant
60-100, normal, one, 0.12-0.20, .04-.10 - Answer-Normal Sinus Rhythm is the rhythm
originating from the SA node that meets these ECG criteria:
REVIEW QUESTIONS AND ANSWERS
Excitability - Answer-the ability of non-pacemaker heart cells to respond to an electrical
impulse that begins in pacemaker cells.
Depolarization - Answer-occurs when the normally negatively charged cells within the
heart muscle develop a positive charge.
Conductivity - Answer-the ability to send an electrical stimulus from cell membrane to
cell membrane. As a result, excitable cells depolarize in rapid succession from cell to
cell until all cells have depolarized. Ex: the wave of depolarization causes the
deflections in the ECG waveforms that are recognized as the P wave and QRS
complex.
Contractility - Answer-the ability of atrial and ventricular muscle cells to shorten their
fiber length in response to electrical stimulation, causing sufficient pressure to push
blood forward through the heart. In other words, this is the mechanical activity of the
heart.
AV Node - Answer-where impulses slow down or are delayed before proceeding to the
ventricles. This delay is reflected in the PR segment on the ECG. This slow conduction
provides a short delay, allowing the atria to contract and the ventricles to fill.
SA Node - Answer-the heart's primary pacemaker. It can spontaneously and
rhythmically generate electrical impulses at a rate of 60-100 beats per min and therefore
has the greatest degree of automaticity.
Purkinje Cells - Answer-composed of the bundle of HIS, bundle branches, and these
fibers. Responsible for the rapid conduction of electrical impulses throughout the
ventricles, leading to ventricular depolarization and the subsequent ventricular muscle
contraction.
Semi-Reclined - Answer-While obtaining a 12-lead ECG, remind the patient be as as
still as possible in a ________________________ position, breathing normally.
Clea, Dry, Moist - Answer-For continous ECG monitoring, be sure to
__________________ skin and clip hairs/shave. Ensure that the electrode placement is
_____________ and the gel on each electrode is ______________ and fresh.
P Wave - Answer-a deflection on an ECG representing atrial depolarization. When the
electrical impulse is consistently generated form the SA node, this wave has a
consistent shape in a given lead. If an impulse is then generated from a different
(ectopic) focus, such as atrial tissue, the shape of this wave changes in the lead,
indicating that an ectopic focus has fired.
, PR Segment - Answer-the isoelectric line from the end of the P wave to the beginning of
the QRS complex, when the electrical impulse is traveling through the AV node, where it
is delayed.
PR Interval - Answer-measured form the beginning of the P wave to the end of the PR
segment. Represents the time required for atrial depolarization, the impulse delay in the
AV node, and the travel time to the Purkinje files. Normally measures from 0.12-0.20
seconds (five small blocks).
QRS Complex - Answer-represents ventricular depolarization on ECG lead.
ST Segment - Answer-an isoelectric line and represents early ventricular repolarization.
Changes may be a result of myocardial injury, ischemia, infarction, conduction
abnormalities or medications.
T wave - Answer-ventricular repolarization, usually positive, rounded, and slightly
asymmetric. May change as a result of myocardial ischemia, potassium/calcium
imbalances, medications, or ANS effects.
U wave - Answer-if this is present, it follows the T wave a may result from slow
depolarization of ventricular Purkinje fibers. An abnormal U wave may suggest an
electrolyte abnormality (Hypokalemia).
QT Interval - Answer-represent the total time required for ventricular depolarization and
depolarization. Measured from the beginning of the Q wave to the end of the T wave.
Varies with the patient's age and gender and changes with the heart rate, lengthening
with slower heart rates and shortening with faster rates.
Artifact - Answer-an interference seen on the monitor or rhythm strip, which may look
like a wandering or fuzzy baseline. It can be caused by patient movements, loose or
defective electrodes, improper grounding, or faulty ECG equipment such as broken
worse or cables. Some can mimic lethal dysrhythmias such as ventricular tachycardia or
ventricular fibrillation. ASSESS PATIENT TO DIFFERENTIATE ARTIFACT FROM
ACTUAL LETHAL RHYTHMS. DO NOT RELY ONLY ON THE ECG MONITOR.
Normal Sinus Rhythm - Answer-the rhythm originating from the SA node that meets
these ECG criteria:
-Rate: 60-100bpm
-Rhythm: atrial and ventricular rhythms regular
-P waves: present, consistent configuration, one P wave before each QRS complex
-PR Interval: 0.12-0.20 seconds and constant
-QRS Duration: 0.04-0.10 second and constant
60-100, normal, one, 0.12-0.20, .04-.10 - Answer-Normal Sinus Rhythm is the rhythm
originating from the SA node that meets these ECG criteria:
