Dysrythmias ( questions) Answered Correctly Latest Update 2025-2026
PR interval.
Rationale: The PR interval represents depolarization of the atria, AV node, bundle of His, bundle
branches, and the Purkinje fibers, up to the point of depolarization of the ventricular cells. -
Answers In analyzing a patient's electrocardiographic (ECG) rhythm strip, the nurse uses the
knowledge that the time of the conduction of an impulse through the Purkinje fibers is
represented by the
use the 3-second markers to count the number of QRS complexes in 6 seconds and multiply by
10.
Rationale: This is the quickest way to determine the ventricular rate for a patient with a regular
rhythm. - Answers When needing to estimate the ventricular rate quickly for a patient with a
regular heart rhythm using an ECG strip, the nurse will
40-60
If the SA node fails to discharge, the junction will automatically discharge at the normal
junctional rate of 40 to 60. - Answers A patient has a junctional escape rhythm on the monitor.
The nurse would expect the patient to have a pulse rate of ____ beats/min.
Obtain further information about possible causes for the heart rate.
Rationale: The patient has sinus tachycardia, which may be caused by multiple stressors such
as pain, dehydration, or myocardial ischemia; further assessment is needed before determining
the treatment. - Answers A patient who is complaining of a "racing" heart and nervousness
comes to the emergency department. The patient's blood pressure (BP) is 102/68. The nurse
places the patient on a cardiac monitor and obtains the following ECG tracing.
Which action should the nurse take next?
MCL1
Rationale: Leads II and MCL1 are the best leads for visualization of P waves, which reflect atrial
activity. - Answers A patient has a dysrhythmia that requires careful monitoring of atrial activity.
Which lead will be best to use for continuous monitoring?
ventricular tachycardia.
Rationale: The absence of P waves, wide QRS, rate >150, and the regularity of the rhythm
indicate ventricular tachycardia. - Answers The nurse obtains a monitor strip on a patient
admitted to the coronary care unit with a myocardial infarction and makes the following analysis:
P wave not apparent; ventricular rate 162, R-R interval regular; PR interval not measurable; and
QRS complex wide and distorted, QRS duration 0.18 second. The nurse interprets the patient's
,cardiac rhythm as
every other QRS complex is wide and starts prematurely.
Rationale: Ventricular bigeminy describes a rhythm in which every other QRS complex is wide
and bizarre looking. - Answers The nurse determines that a patient has ventricular bigeminy
when the rhythm strip indicates that
document the finding and continue to monitor the patient
.Rationale: First-degree atrioventricular (AV) block is asymptomatic and requires ongoing
monitoring because it may progress to more serious forms of heart block. - Answers A patient
has a normal cardiac rhythm strip except that the PR interval is 0.34 seconds. The appropriate
intervention by the nurse is to
hypokalemia.
Rationale: Hypokalemia increases the risk for ventricular dysrhythmias such as PVCs,
ventricular tachycardia, and ventricular fibrillation. - Answers A patient with diabetes mellitus is
admitted unresponsive to the emergency department (ED). Initial laboratory findings are serum
potassium 2.8 mEq/L (2.8 mmol/L), serum sodium 138 mEq/L (138 mmol/L), serum chloride 90
mEq/L (90 mmol/L), and blood glucose 628 mg/dl (34.9 mmol/L). Cardiac monitoring shows
multifocal PVCs. The nurse understands that the patient's PVCs are most likely caused by
administer IV antidysrhythmic drugs per protocol.
Rationale: The burst of sustained ventricular tachycardia indicates that the patient has
significant ventricular irritability, and antidysrhythmic medication administration is needed to
prevent further episodes. - Answers The nurse reviews data from the cardiac monitor indicating
that a patient with a myocardial infarction experienced a 50-second episode of ventricular
tachycardia before a sinus rhythm and a heart rate of 98 were re-established. The most
appropriate initial action by the nurse is to
third-degree AV block.
Rationale: The inconsistency between the atrial and ventricular rates and the variable PR interval
indicate that the rhythm is third-degree AV block. - Answers A patient experiences dizziness and
shortness of breath for several days. During cardiac monitoring in the ED, the nurse obtains the
following ECG tracing. The nurse interprets this cardiac rhythm as
increase in the patient's heart rate.
Rationale: Atropine will increase the heart rate and conduction through the AV node. - Answers
A patient with myocardial infarction develops symptomatic hypotension. The monitor shows a
type 1, second-degree AV block with a heart rate of 30. The nurse administers IV atropine as
prescribed. The nurse determines that the drug has been effective on finding a(n)
, anticoagulant therapy with warfarin (Coumadin).
Rationale: Atrial fibrillation therapy that has persisted for more than 48 hours requires
anticoagulant treatment for 3 to 4 weeks before attempting cardioversion; this is done to
prevent embolization of clots from the atria - Answers A patient with dilated cardiomyopathy
has an atrial fibrillation that has been unresponsive to drug therapy for several days. The nurse
anticipates that further treatment of the patient will require
start basic cardiopulmonary resuscitation (CPR).
Rationale: The patient's rhythm and assessment indicate ventricular fibrillation and cardiac
arrest; therefore, the initial actions include calling for help, and initiating CPR until defibrillation
is possible. - Answers The nurse hears the cardiac monitor alarm and notes that the patient has
a cardiac pattern of undulations of varying contours and amplitude with no measurable ECG
pattern. The patient is unconscious with no pulse or respirations. After calling for assistance,
the nurse should
apical radial heart rate.
Rationale: It is important to assess the patient's apical-radial pulse rate because PVCs often do
not generate a sufficient ventricular contraction to result in a peripheral pulse, which can lead to
a pulse deficit. - Answers During change-of-shift report, the nurse learns that a patient with a
large myocardial infarction has been having frequent PVCs. When monitoring the patient for the
effects of PVCs, the nurse will check the patient's
"You had a serious abnormal heart rhythm, which treatment was able to reverse."
Rationale: This response honestly describes what happened to the patient while avoiding
unnecessarily increasing the patient's anxiety level. More information may be given by the nurse
if the patient asks further questions. - Answers A patient who has been successfully
resuscitated after developing ventricular fibrillation asks the nurse about what happened. The
most appropriate response by the nurse is,
stimulate a heart beat if the patient's own heart rate drops too low.
Rationale: The permanent pacemaker will discharge when the ventricular rate drops below the
set rate. - Answers A patient has a permanent pacemaker inserted for treatment of chronic
atrial fibrillation with slow ventricular response. The nurse teaches the patient that the
pacemaker will
"I won't lift the arm on the pacemaker side up very high until I see the doctor."
Rationale: The patient is instructed to avoid lifting the arm on the pacemaker side above the
shoulder to avoid displacing the pacemaker leads. - Answers A patient has received instruction
on the management of a new permanent pacemaker before discharge from the hospital. The
PR interval.
Rationale: The PR interval represents depolarization of the atria, AV node, bundle of His, bundle
branches, and the Purkinje fibers, up to the point of depolarization of the ventricular cells. -
Answers In analyzing a patient's electrocardiographic (ECG) rhythm strip, the nurse uses the
knowledge that the time of the conduction of an impulse through the Purkinje fibers is
represented by the
use the 3-second markers to count the number of QRS complexes in 6 seconds and multiply by
10.
Rationale: This is the quickest way to determine the ventricular rate for a patient with a regular
rhythm. - Answers When needing to estimate the ventricular rate quickly for a patient with a
regular heart rhythm using an ECG strip, the nurse will
40-60
If the SA node fails to discharge, the junction will automatically discharge at the normal
junctional rate of 40 to 60. - Answers A patient has a junctional escape rhythm on the monitor.
The nurse would expect the patient to have a pulse rate of ____ beats/min.
Obtain further information about possible causes for the heart rate.
Rationale: The patient has sinus tachycardia, which may be caused by multiple stressors such
as pain, dehydration, or myocardial ischemia; further assessment is needed before determining
the treatment. - Answers A patient who is complaining of a "racing" heart and nervousness
comes to the emergency department. The patient's blood pressure (BP) is 102/68. The nurse
places the patient on a cardiac monitor and obtains the following ECG tracing.
Which action should the nurse take next?
MCL1
Rationale: Leads II and MCL1 are the best leads for visualization of P waves, which reflect atrial
activity. - Answers A patient has a dysrhythmia that requires careful monitoring of atrial activity.
Which lead will be best to use for continuous monitoring?
ventricular tachycardia.
Rationale: The absence of P waves, wide QRS, rate >150, and the regularity of the rhythm
indicate ventricular tachycardia. - Answers The nurse obtains a monitor strip on a patient
admitted to the coronary care unit with a myocardial infarction and makes the following analysis:
P wave not apparent; ventricular rate 162, R-R interval regular; PR interval not measurable; and
QRS complex wide and distorted, QRS duration 0.18 second. The nurse interprets the patient's
,cardiac rhythm as
every other QRS complex is wide and starts prematurely.
Rationale: Ventricular bigeminy describes a rhythm in which every other QRS complex is wide
and bizarre looking. - Answers The nurse determines that a patient has ventricular bigeminy
when the rhythm strip indicates that
document the finding and continue to monitor the patient
.Rationale: First-degree atrioventricular (AV) block is asymptomatic and requires ongoing
monitoring because it may progress to more serious forms of heart block. - Answers A patient
has a normal cardiac rhythm strip except that the PR interval is 0.34 seconds. The appropriate
intervention by the nurse is to
hypokalemia.
Rationale: Hypokalemia increases the risk for ventricular dysrhythmias such as PVCs,
ventricular tachycardia, and ventricular fibrillation. - Answers A patient with diabetes mellitus is
admitted unresponsive to the emergency department (ED). Initial laboratory findings are serum
potassium 2.8 mEq/L (2.8 mmol/L), serum sodium 138 mEq/L (138 mmol/L), serum chloride 90
mEq/L (90 mmol/L), and blood glucose 628 mg/dl (34.9 mmol/L). Cardiac monitoring shows
multifocal PVCs. The nurse understands that the patient's PVCs are most likely caused by
administer IV antidysrhythmic drugs per protocol.
Rationale: The burst of sustained ventricular tachycardia indicates that the patient has
significant ventricular irritability, and antidysrhythmic medication administration is needed to
prevent further episodes. - Answers The nurse reviews data from the cardiac monitor indicating
that a patient with a myocardial infarction experienced a 50-second episode of ventricular
tachycardia before a sinus rhythm and a heart rate of 98 were re-established. The most
appropriate initial action by the nurse is to
third-degree AV block.
Rationale: The inconsistency between the atrial and ventricular rates and the variable PR interval
indicate that the rhythm is third-degree AV block. - Answers A patient experiences dizziness and
shortness of breath for several days. During cardiac monitoring in the ED, the nurse obtains the
following ECG tracing. The nurse interprets this cardiac rhythm as
increase in the patient's heart rate.
Rationale: Atropine will increase the heart rate and conduction through the AV node. - Answers
A patient with myocardial infarction develops symptomatic hypotension. The monitor shows a
type 1, second-degree AV block with a heart rate of 30. The nurse administers IV atropine as
prescribed. The nurse determines that the drug has been effective on finding a(n)
, anticoagulant therapy with warfarin (Coumadin).
Rationale: Atrial fibrillation therapy that has persisted for more than 48 hours requires
anticoagulant treatment for 3 to 4 weeks before attempting cardioversion; this is done to
prevent embolization of clots from the atria - Answers A patient with dilated cardiomyopathy
has an atrial fibrillation that has been unresponsive to drug therapy for several days. The nurse
anticipates that further treatment of the patient will require
start basic cardiopulmonary resuscitation (CPR).
Rationale: The patient's rhythm and assessment indicate ventricular fibrillation and cardiac
arrest; therefore, the initial actions include calling for help, and initiating CPR until defibrillation
is possible. - Answers The nurse hears the cardiac monitor alarm and notes that the patient has
a cardiac pattern of undulations of varying contours and amplitude with no measurable ECG
pattern. The patient is unconscious with no pulse or respirations. After calling for assistance,
the nurse should
apical radial heart rate.
Rationale: It is important to assess the patient's apical-radial pulse rate because PVCs often do
not generate a sufficient ventricular contraction to result in a peripheral pulse, which can lead to
a pulse deficit. - Answers During change-of-shift report, the nurse learns that a patient with a
large myocardial infarction has been having frequent PVCs. When monitoring the patient for the
effects of PVCs, the nurse will check the patient's
"You had a serious abnormal heart rhythm, which treatment was able to reverse."
Rationale: This response honestly describes what happened to the patient while avoiding
unnecessarily increasing the patient's anxiety level. More information may be given by the nurse
if the patient asks further questions. - Answers A patient who has been successfully
resuscitated after developing ventricular fibrillation asks the nurse about what happened. The
most appropriate response by the nurse is,
stimulate a heart beat if the patient's own heart rate drops too low.
Rationale: The permanent pacemaker will discharge when the ventricular rate drops below the
set rate. - Answers A patient has a permanent pacemaker inserted for treatment of chronic
atrial fibrillation with slow ventricular response. The nurse teaches the patient that the
pacemaker will
"I won't lift the arm on the pacemaker side up very high until I see the doctor."
Rationale: The patient is instructed to avoid lifting the arm on the pacemaker side above the
shoulder to avoid displacing the pacemaker leads. - Answers A patient has received instruction
on the management of a new permanent pacemaker before discharge from the hospital. The
