Advanced – Dysrhythmias Exam Test with Verified Answers
Graded A+
1. Excitability the ability of non-pacemaker heart cells
to respond to an electrical impulse that
begins in pacemaker cells.
2. Depolarization occurs when the normally negatively
charged cells within the heart muscle de-
velop a positive charge.
3. Conductivity 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 depolar-
ization causes the deflections in the ECG
waveforms that are recognized as the P
wave and QRS complex.
4. Contractility the ability of atrial and ventricular muscle
cells to shorten their fiber length in re-
sponse to electrical stimulation, causing
sufficient pressure to push blood forward
through the heart. In other words, this is
the mechanical activity of the heart.
5. AV Node 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.
6. SA Node 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 great-
est degree of automaticity.
7. Purkinje Cells composed of the bundle of HIS, bundle
branches, and these fibers. Responsible
,Advanced – Dysrhythmias Exam Test with Verified Answers
Graded A+
for the rapid conduction of electrical im-
pulses throughout the ventricles, leading
to ventricular depolarization and the sub-
sequent ventricular muscle contraction.
8. Semi-Reclined While obtaining a 12-lead ECG, remind
the patient be as as still as possible in
a position,
breathing normally.
9. Clea, Dry, Moist 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.
10. P Wave a deflection on an ECG representing atri-
al depolarization. When the electrical im-
pulse is consistently generated form the
SA node, this wave has a consistent shape
in a given lead. If an impulse is then gener-
ated from a different (ectopic) focus, such
as atrial tissue, the shape of this wave
changes in the lead, indicating that an ec-
topic focus has fired.
11. PR Segment the isoelectric line from the end of the P
wave to the beginning of the QRS com-
plex, when the electrical impulse is travel-
ing through the AV node, where it is de-
layed.
12. PR Interval measured form the beginning of the P
wave to the end of the PR segment. Rep-
resents the time required for atrial depolar-
ization, the impulse delay in the AV node,
and the travel time to the Purkinje files.
Normally measures from 0.12-0.20 sec-
onds (five small blocks).
, 13. QRS Complex represents ventricular depolarization on
ECG lead.
14. ST Segment an isoelectric line and represents early
ventricular repolarization. Changes may
be a result of myocardial injury, ischemia,
infarction, conduction abnormalities or
medications.
15. T wave ventricular repolarization, usually positive,
rounded, and slightly asymmetric. May
change as a result of myocardial ischemia,
potassium/calcium imbalances, medica-
tions, or ANS effects.
16. U wave 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 abnor-
mality (Hypokalemia).
17. QT Interval represent the total time required for ven-
tricular 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 slow-
er heart rates and shortening with faster
rates.
18. Artifact an interference seen on the monitor or
rhythm strip, which may look like a wan-
dering 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 dysrhyth-
mias such as ventricular tachycardia or
ventricular fibrillation. ASSESS PATIENT
Graded A+
1. Excitability the ability of non-pacemaker heart cells
to respond to an electrical impulse that
begins in pacemaker cells.
2. Depolarization occurs when the normally negatively
charged cells within the heart muscle de-
velop a positive charge.
3. Conductivity 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 depolar-
ization causes the deflections in the ECG
waveforms that are recognized as the P
wave and QRS complex.
4. Contractility the ability of atrial and ventricular muscle
cells to shorten their fiber length in re-
sponse to electrical stimulation, causing
sufficient pressure to push blood forward
through the heart. In other words, this is
the mechanical activity of the heart.
5. AV Node 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.
6. SA Node 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 great-
est degree of automaticity.
7. Purkinje Cells composed of the bundle of HIS, bundle
branches, and these fibers. Responsible
,Advanced – Dysrhythmias Exam Test with Verified Answers
Graded A+
for the rapid conduction of electrical im-
pulses throughout the ventricles, leading
to ventricular depolarization and the sub-
sequent ventricular muscle contraction.
8. Semi-Reclined While obtaining a 12-lead ECG, remind
the patient be as as still as possible in
a position,
breathing normally.
9. Clea, Dry, Moist 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.
10. P Wave a deflection on an ECG representing atri-
al depolarization. When the electrical im-
pulse is consistently generated form the
SA node, this wave has a consistent shape
in a given lead. If an impulse is then gener-
ated from a different (ectopic) focus, such
as atrial tissue, the shape of this wave
changes in the lead, indicating that an ec-
topic focus has fired.
11. PR Segment the isoelectric line from the end of the P
wave to the beginning of the QRS com-
plex, when the electrical impulse is travel-
ing through the AV node, where it is de-
layed.
12. PR Interval measured form the beginning of the P
wave to the end of the PR segment. Rep-
resents the time required for atrial depolar-
ization, the impulse delay in the AV node,
and the travel time to the Purkinje files.
Normally measures from 0.12-0.20 sec-
onds (five small blocks).
, 13. QRS Complex represents ventricular depolarization on
ECG lead.
14. ST Segment an isoelectric line and represents early
ventricular repolarization. Changes may
be a result of myocardial injury, ischemia,
infarction, conduction abnormalities or
medications.
15. T wave ventricular repolarization, usually positive,
rounded, and slightly asymmetric. May
change as a result of myocardial ischemia,
potassium/calcium imbalances, medica-
tions, or ANS effects.
16. U wave 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 abnor-
mality (Hypokalemia).
17. QT Interval represent the total time required for ven-
tricular 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 slow-
er heart rates and shortening with faster
rates.
18. Artifact an interference seen on the monitor or
rhythm strip, which may look like a wan-
dering 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 dysrhyth-
mias such as ventricular tachycardia or
ventricular fibrillation. ASSESS PATIENT
