The Ultimate and Complete Baylor Scott & White EKG Study Guide 2025–2026,
Covering Electrocardiography Fundamentals, Cardiac Electrical Conduction System
and ECG Lead Placement, Standard 12-Lead EKG Acquisition and Interpretation, P
Waves QRS Complexes and T Waves, PR QRS and QT Interval Measurement, Normal
Sinus Rhythm and Common Cardiac Arrhythmias, Atrial Fibrillation and Atrial Flutter,
Supraventricular and Ventricular Tachycardias, Bradycardias and Heart Block
Recognition, Premature Atrial and Ventricular Contractions, ST-Segment and T-Wave
Changes, Myocardial Ischemia and Infarction Patterns, Electrolyte-Related EKG
Changes, Artifact Recognition and Troubleshooting, EKG Monitoring and Patient
Safety, Clinical Rhythm Interpretation, Practice Questions with Verified Answers and
Detailed Rationales, Realistic Cardiac Rhythm Scenarios, Step-by-Step EKG
Interpretation Frameworks, and Proven Strategies to Successfully Prepare for
Baylor Scott & White EKG Competency Assessments
Question 1: A 65-year-old male patient in the telemetry unit has a continuous EKG strip
showing a regular rhythm with a heart rate of 72 beats per minute, a PR interval of 0.16
seconds, and a QRS duration of 0.08 seconds. The P waves are upright and uniform in lead II.
Which of the following best describes this rhythm and the most appropriate nursing action?
A. Sinus bradycardia; administer atropine immediately. B. Normal sinus rhythm; continue
routine monitoring and document findings. C. First-degree AV block; prepare for
transcutaneous pacing. D. Junctional rhythm; administer intravenous epinephrine.
CORRECT ANSWER: B. Normal sinus rhythm; continue routine monitoring and document
findings. Rationale: The EKG findings indicate a normal sinus rhythm (NSR) because the rate is
between 60-100 bpm, the rhythm is regular, P waves are upright and precede every QRS
complex, the PR interval is within normal limits (0.12-0.20 seconds), and the QRS complex is
narrow (0.04-0.10 seconds). Since the patient is stable and the rhythm is normal, routine
monitoring and documentation are appropriate.
Question 2: A patient on the medical-surgical unit complains of dizziness. The telemetry
monitor displays a regular rhythm with a heart rate of 42 bpm, a normal PR interval, and a
narrow QRS complex. The patient's blood pressure is 88/54 mmHg. What is the priority
nursing intervention? A. Administer a beta-blocker to control the heart rate. B. Administer
atropine sulfate intravenously as prescribed. C. Perform immediate synchronized cardioversion.
D. Instruct the patient to bear down (Valsalva maneuver).
CORRECT ANSWER: B. Administer atropine sulfate intravenously as prescribed. Rationale: The
patient is experiencing symptomatic sinus bradycardia (heart rate < 60 bpm with hypotension
and dizziness). According to ACLS guidelines, the first-line medication for symptomatic
bradycardia is Atropine. Beta-blockers would worsen the bradycardia, cardioversion is not
indicated for bradycardia, and vagal maneuvers are used for tachyarrhythmias like SVT.
,Question 3: A 45-year-old female presents to the ER with palpitations. The EKG shows a
regular rhythm with a heart rate of 165 bpm. P waves are absent, and the QRS complexes are
narrow. The patient is stable and awake. Which initial intervention is most appropriate? A.
Administer IV amiodarone. B. Perform unsynchronized defibrillation. C. Attempt vagal
maneuvers. D. Administer IV epinephrine.
CORRECT ANSWER: C. Attempt vagal maneuvers. Rationale: The rhythm is likely Paroxysmal
Supraventricular Tachycardia (PSVT) due to the regular, narrow-complex tachycardia with
absent P waves. For a stable patient with PSVT, the initial interventions are vagal maneuvers
(e.g., Valsalva, carotid sinus massage). If unsuccessful, adenosine is the next step. Defibrillation
is for pulseless VT/VF.
Question 4: A patient with chronic obstructive pulmonary disease (COPD) is admitted with
pneumonia. The EKG shows an irregularly irregular rhythm with no discernible P waves and a
ventricular rate of 110 bpm. What is a major complication the nurse must monitor for in this
patient? A. Third-degree AV block. B. Embolic stroke. C. Ventricular fibrillation. D. Asystole.
CORRECT ANSWER: B. Embolic stroke. Rationale: The EKG describes Atrial Fibrillation (AFib),
characterized by an irregularly irregular rhythm and absent P waves. Blood pools in the atria,
leading to thrombus formation. If a thrombus dislodges, it can travel to the brain, causing an
embolic stroke. Anticoagulation therapy is often required to mitigate this risk.
Question 5: While reviewing an EKG strip, the nurse notes a heart rate of 50 bpm. The PR
interval is 0.28 seconds and remains constant before every QRS complex. The QRS duration is
0.08 seconds. What rhythm is this? A. Second-degree AV block, Type I. B. Second-degree AV
block, Type II. C. First-degree AV block. D. Third-degree AV block.
CORRECT ANSWER: C. First-degree AV block. Rationale: First-degree AV block is characterized
by a prolonged PR interval (> 0.20 seconds) that remains constant before every QRS complex.
Every P wave is followed by a QRS complex. It is usually asymptomatic and requires no specific
treatment unless accompanied by severe bradycardia.
Question 6: A patient in the ICU has an EKG strip showing a progressive prolongation of the
PR interval until a P wave is completely blocked and no QRS complex follows. After the
dropped beat, the PR interval resets and the cycle repeats. What is this rhythm? A. First-
degree AV block. B. Second-degree AV block, Type I (Wenckebach). C. Second-degree AV block,
Type II. D. Third-degree AV block.
CORRECT ANSWER: B. Second-degree AV block, Type I (Wenckebach). Rationale: Second-
degree AV block, Type I (Wenckebach or Mobitz I), is identified by a progressive lengthening of
the PR interval until a beat is dropped (a P wave without a subsequent QRS). This is typically a
benign rhythm originating in the AV node and may not require treatment unless the patient is
symptomatic.
,Question 7: An EKG strip shows a regular atrial rate of 300 bpm and a ventricular rate of 150
bpm. The baseline between QRS complexes shows a "sawtooth" pattern. Which rhythm is
present? A. Atrial fibrillation. B. Atrial flutter. C. Ventricular tachycardia. D. Sinus tachycardia.
CORRECT ANSWER: B. Atrial flutter. Rationale: Atrial flutter is characterized by a rapid, regular
atrial rate (typically 250-350 bpm) with a classic "sawtooth" appearance of the flutter waves (F
waves). The ventricular rate is often a fraction of the atrial rate (e.g., 2:1 conduction resulting in
a ventricular rate of 150 bpm).
Question 8: A patient on telemetry suddenly develops a wide-complex tachycardia with a
heart rate of 180 bpm. The patient is unresponsive, pulseless, and apneic. What is the
immediate priority action? A. Administer IV amiodarone. B. Perform synchronized
cardioversion. C. Initiate high-quality CPR and prepare for defibrillation. D. Administer IV
epinephrine.
CORRECT ANSWER: C. Initiate high-quality CPR and prepare for defibrillation. Rationale: The
patient is in pulseless Ventricular Tachycardia (pVT). According to ACLS guidelines, the
immediate treatment for pulseless VT or VF is high-quality CPR and early defibrillation
(unsynchronized shock). Medications like epinephrine and amiodarone are given during CPR
but do not replace the immediate need for chest compressions and defibrillation.
Question 9: A patient with a history of myocardial infarction is being monitored on telemetry.
The EKG shows a wide QRS complex (>0.12 seconds) occurring earlier than expected, followed
by a compensatory pause. The T wave is directed opposite to the QRS complex. What is this
ectopic beat? A. Premature Atrial Contraction (PAC). B. Premature Junctional Contraction (PJC).
C. Premature Ventricular Contraction (PVC). D. Supraventricular Tachycardia (SVT).
CORRECT ANSWER: C. Premature Ventricular Contraction (PVC). Rationale: PVCs are
characterized by wide, bizarre QRS complexes (>0.12 seconds) that occur earlier than expected,
without a preceding P wave. The T wave is typically deflected in the opposite direction of the
QRS complex. PVCs are often followed by a full compensatory pause.
Question 10: A patient is admitted with severe hypokalemia (potassium level of 2.5 mEq/L).
Which EKG change is the nurse most likely to observe on the telemetry monitor? A. Peaked T
waves and widened QRS complexes. B. Prominent U waves and ST segment depression. C.
Shortened QT interval and absent P waves. D. ST segment elevation and deep Q waves.
CORRECT ANSWER: B. Prominent U waves and ST segment depression. Rationale:
Hypokalemia commonly presents on an EKG with ST segment depression, flattened or inverted
T waves, and prominent U waves. Severe hypokalemia can lead to dangerous arrhythmias like
PVCs, VT, or VF. Peaked T waves are associated with hyperkalemia.
Question 11: A patient with a serum potassium level of 6.8 mEq/L is admitted to the cardiac
unit. Which EKG finding is most concerning and indicative of severe hyperkalemia? A.
, Prominent U waves. B. Shortened PR interval. C. Peaked T waves and widened QRS complexes.
D. ST segment elevation in leads V1-V3.
CORRECT ANSWER: C. Peaked T waves and widened QRS complexes. Rationale: Hyperkalemia
initially presents with tall, peaked T waves. As potassium levels rise, the PR interval prolongs, P
waves flatten or disappear, and the QRS complex widens. A widened QRS can merge with the T
wave to form a sine-wave pattern, which can rapidly degenerate into ventricular fibrillation or
asystole.
Question 12: A 55-year-old male presents with crushing chest pain. A 12-lead EKG shows ST-
segment elevation in leads II, III, and aVF. Which area of the myocardium is most likely
experiencing an acute infarction? A. Anterior wall. B. Lateral wall. C. Inferior wall. D. Posterior
wall.
CORRECT ANSWER: C. Inferior wall. Rationale: ST-segment elevation in leads II, III, and aVF
indicates an acute inferior wall myocardial infarction. These leads look at the inferior surface of
the heart, which is typically supplied by the right coronary artery (RCA). Anterior MI shows
changes in V1-V4, lateral in I, aVL, V5, V6.
Question 13: During a code blue, the monitor shows a chaotic, irregular waveform with no
identifiable P waves, QRS complexes, or T waves. The patient has no pulse. What is this
rhythm and the definitive treatment? A. Pulseless Electrical Activity (PEA); administer
epinephrine. B. Asystole; perform transcutaneous pacing. C. Ventricular Fibrillation (VF);
perform defibrillation. D. Agonal rhythm; administer atropine.
CORRECT ANSWER: C. Ventricular Fibrillation (VF); perform defibrillation. Rationale: The
rhythm described is Ventricular Fibrillation (VF), a chaotic rhythm with no effective cardiac
output. The definitive treatment for VF is immediate unsynchronized defibrillation combined
with high-quality CPR. Epinephrine is given to improve coronary perfusion pressure but does
not convert the rhythm.
Question 14: A patient with a permanent ventricular pacemaker has an EKG showing a pacing
spike that is not followed by a QRS complex. What is this pacemaker malfunction called? A.
Failure to pace. B. Failure to capture. C. Failure to sense. D. Undersensing.
CORRECT ANSWER: B. Failure to capture. Rationale: Failure to capture occurs when the
pacemaker generates an electrical impulse (seen as a pacing spike), but the myocardium does
not depolarize in response (no subsequent P wave or QRS complex). Causes include lead
dislodgement, myocardial ischemia, electrolyte imbalances, or increased pacing threshold.
Question 15: A patient's EKG shows a pacing spike occurring immediately after a patient's
intrinsic QRS complex. What type of pacemaker malfunction is this? A. Failure to pace. B.
Failure to capture. C. Failure to sense (Undersensing). D. Oversensing.
Covering Electrocardiography Fundamentals, Cardiac Electrical Conduction System
and ECG Lead Placement, Standard 12-Lead EKG Acquisition and Interpretation, P
Waves QRS Complexes and T Waves, PR QRS and QT Interval Measurement, Normal
Sinus Rhythm and Common Cardiac Arrhythmias, Atrial Fibrillation and Atrial Flutter,
Supraventricular and Ventricular Tachycardias, Bradycardias and Heart Block
Recognition, Premature Atrial and Ventricular Contractions, ST-Segment and T-Wave
Changes, Myocardial Ischemia and Infarction Patterns, Electrolyte-Related EKG
Changes, Artifact Recognition and Troubleshooting, EKG Monitoring and Patient
Safety, Clinical Rhythm Interpretation, Practice Questions with Verified Answers and
Detailed Rationales, Realistic Cardiac Rhythm Scenarios, Step-by-Step EKG
Interpretation Frameworks, and Proven Strategies to Successfully Prepare for
Baylor Scott & White EKG Competency Assessments
Question 1: A 65-year-old male patient in the telemetry unit has a continuous EKG strip
showing a regular rhythm with a heart rate of 72 beats per minute, a PR interval of 0.16
seconds, and a QRS duration of 0.08 seconds. The P waves are upright and uniform in lead II.
Which of the following best describes this rhythm and the most appropriate nursing action?
A. Sinus bradycardia; administer atropine immediately. B. Normal sinus rhythm; continue
routine monitoring and document findings. C. First-degree AV block; prepare for
transcutaneous pacing. D. Junctional rhythm; administer intravenous epinephrine.
CORRECT ANSWER: B. Normal sinus rhythm; continue routine monitoring and document
findings. Rationale: The EKG findings indicate a normal sinus rhythm (NSR) because the rate is
between 60-100 bpm, the rhythm is regular, P waves are upright and precede every QRS
complex, the PR interval is within normal limits (0.12-0.20 seconds), and the QRS complex is
narrow (0.04-0.10 seconds). Since the patient is stable and the rhythm is normal, routine
monitoring and documentation are appropriate.
Question 2: A patient on the medical-surgical unit complains of dizziness. The telemetry
monitor displays a regular rhythm with a heart rate of 42 bpm, a normal PR interval, and a
narrow QRS complex. The patient's blood pressure is 88/54 mmHg. What is the priority
nursing intervention? A. Administer a beta-blocker to control the heart rate. B. Administer
atropine sulfate intravenously as prescribed. C. Perform immediate synchronized cardioversion.
D. Instruct the patient to bear down (Valsalva maneuver).
CORRECT ANSWER: B. Administer atropine sulfate intravenously as prescribed. Rationale: The
patient is experiencing symptomatic sinus bradycardia (heart rate < 60 bpm with hypotension
and dizziness). According to ACLS guidelines, the first-line medication for symptomatic
bradycardia is Atropine. Beta-blockers would worsen the bradycardia, cardioversion is not
indicated for bradycardia, and vagal maneuvers are used for tachyarrhythmias like SVT.
,Question 3: A 45-year-old female presents to the ER with palpitations. The EKG shows a
regular rhythm with a heart rate of 165 bpm. P waves are absent, and the QRS complexes are
narrow. The patient is stable and awake. Which initial intervention is most appropriate? A.
Administer IV amiodarone. B. Perform unsynchronized defibrillation. C. Attempt vagal
maneuvers. D. Administer IV epinephrine.
CORRECT ANSWER: C. Attempt vagal maneuvers. Rationale: The rhythm is likely Paroxysmal
Supraventricular Tachycardia (PSVT) due to the regular, narrow-complex tachycardia with
absent P waves. For a stable patient with PSVT, the initial interventions are vagal maneuvers
(e.g., Valsalva, carotid sinus massage). If unsuccessful, adenosine is the next step. Defibrillation
is for pulseless VT/VF.
Question 4: A patient with chronic obstructive pulmonary disease (COPD) is admitted with
pneumonia. The EKG shows an irregularly irregular rhythm with no discernible P waves and a
ventricular rate of 110 bpm. What is a major complication the nurse must monitor for in this
patient? A. Third-degree AV block. B. Embolic stroke. C. Ventricular fibrillation. D. Asystole.
CORRECT ANSWER: B. Embolic stroke. Rationale: The EKG describes Atrial Fibrillation (AFib),
characterized by an irregularly irregular rhythm and absent P waves. Blood pools in the atria,
leading to thrombus formation. If a thrombus dislodges, it can travel to the brain, causing an
embolic stroke. Anticoagulation therapy is often required to mitigate this risk.
Question 5: While reviewing an EKG strip, the nurse notes a heart rate of 50 bpm. The PR
interval is 0.28 seconds and remains constant before every QRS complex. The QRS duration is
0.08 seconds. What rhythm is this? A. Second-degree AV block, Type I. B. Second-degree AV
block, Type II. C. First-degree AV block. D. Third-degree AV block.
CORRECT ANSWER: C. First-degree AV block. Rationale: First-degree AV block is characterized
by a prolonged PR interval (> 0.20 seconds) that remains constant before every QRS complex.
Every P wave is followed by a QRS complex. It is usually asymptomatic and requires no specific
treatment unless accompanied by severe bradycardia.
Question 6: A patient in the ICU has an EKG strip showing a progressive prolongation of the
PR interval until a P wave is completely blocked and no QRS complex follows. After the
dropped beat, the PR interval resets and the cycle repeats. What is this rhythm? A. First-
degree AV block. B. Second-degree AV block, Type I (Wenckebach). C. Second-degree AV block,
Type II. D. Third-degree AV block.
CORRECT ANSWER: B. Second-degree AV block, Type I (Wenckebach). Rationale: Second-
degree AV block, Type I (Wenckebach or Mobitz I), is identified by a progressive lengthening of
the PR interval until a beat is dropped (a P wave without a subsequent QRS). This is typically a
benign rhythm originating in the AV node and may not require treatment unless the patient is
symptomatic.
,Question 7: An EKG strip shows a regular atrial rate of 300 bpm and a ventricular rate of 150
bpm. The baseline between QRS complexes shows a "sawtooth" pattern. Which rhythm is
present? A. Atrial fibrillation. B. Atrial flutter. C. Ventricular tachycardia. D. Sinus tachycardia.
CORRECT ANSWER: B. Atrial flutter. Rationale: Atrial flutter is characterized by a rapid, regular
atrial rate (typically 250-350 bpm) with a classic "sawtooth" appearance of the flutter waves (F
waves). The ventricular rate is often a fraction of the atrial rate (e.g., 2:1 conduction resulting in
a ventricular rate of 150 bpm).
Question 8: A patient on telemetry suddenly develops a wide-complex tachycardia with a
heart rate of 180 bpm. The patient is unresponsive, pulseless, and apneic. What is the
immediate priority action? A. Administer IV amiodarone. B. Perform synchronized
cardioversion. C. Initiate high-quality CPR and prepare for defibrillation. D. Administer IV
epinephrine.
CORRECT ANSWER: C. Initiate high-quality CPR and prepare for defibrillation. Rationale: The
patient is in pulseless Ventricular Tachycardia (pVT). According to ACLS guidelines, the
immediate treatment for pulseless VT or VF is high-quality CPR and early defibrillation
(unsynchronized shock). Medications like epinephrine and amiodarone are given during CPR
but do not replace the immediate need for chest compressions and defibrillation.
Question 9: A patient with a history of myocardial infarction is being monitored on telemetry.
The EKG shows a wide QRS complex (>0.12 seconds) occurring earlier than expected, followed
by a compensatory pause. The T wave is directed opposite to the QRS complex. What is this
ectopic beat? A. Premature Atrial Contraction (PAC). B. Premature Junctional Contraction (PJC).
C. Premature Ventricular Contraction (PVC). D. Supraventricular Tachycardia (SVT).
CORRECT ANSWER: C. Premature Ventricular Contraction (PVC). Rationale: PVCs are
characterized by wide, bizarre QRS complexes (>0.12 seconds) that occur earlier than expected,
without a preceding P wave. The T wave is typically deflected in the opposite direction of the
QRS complex. PVCs are often followed by a full compensatory pause.
Question 10: A patient is admitted with severe hypokalemia (potassium level of 2.5 mEq/L).
Which EKG change is the nurse most likely to observe on the telemetry monitor? A. Peaked T
waves and widened QRS complexes. B. Prominent U waves and ST segment depression. C.
Shortened QT interval and absent P waves. D. ST segment elevation and deep Q waves.
CORRECT ANSWER: B. Prominent U waves and ST segment depression. Rationale:
Hypokalemia commonly presents on an EKG with ST segment depression, flattened or inverted
T waves, and prominent U waves. Severe hypokalemia can lead to dangerous arrhythmias like
PVCs, VT, or VF. Peaked T waves are associated with hyperkalemia.
Question 11: A patient with a serum potassium level of 6.8 mEq/L is admitted to the cardiac
unit. Which EKG finding is most concerning and indicative of severe hyperkalemia? A.
, Prominent U waves. B. Shortened PR interval. C. Peaked T waves and widened QRS complexes.
D. ST segment elevation in leads V1-V3.
CORRECT ANSWER: C. Peaked T waves and widened QRS complexes. Rationale: Hyperkalemia
initially presents with tall, peaked T waves. As potassium levels rise, the PR interval prolongs, P
waves flatten or disappear, and the QRS complex widens. A widened QRS can merge with the T
wave to form a sine-wave pattern, which can rapidly degenerate into ventricular fibrillation or
asystole.
Question 12: A 55-year-old male presents with crushing chest pain. A 12-lead EKG shows ST-
segment elevation in leads II, III, and aVF. Which area of the myocardium is most likely
experiencing an acute infarction? A. Anterior wall. B. Lateral wall. C. Inferior wall. D. Posterior
wall.
CORRECT ANSWER: C. Inferior wall. Rationale: ST-segment elevation in leads II, III, and aVF
indicates an acute inferior wall myocardial infarction. These leads look at the inferior surface of
the heart, which is typically supplied by the right coronary artery (RCA). Anterior MI shows
changes in V1-V4, lateral in I, aVL, V5, V6.
Question 13: During a code blue, the monitor shows a chaotic, irregular waveform with no
identifiable P waves, QRS complexes, or T waves. The patient has no pulse. What is this
rhythm and the definitive treatment? A. Pulseless Electrical Activity (PEA); administer
epinephrine. B. Asystole; perform transcutaneous pacing. C. Ventricular Fibrillation (VF);
perform defibrillation. D. Agonal rhythm; administer atropine.
CORRECT ANSWER: C. Ventricular Fibrillation (VF); perform defibrillation. Rationale: The
rhythm described is Ventricular Fibrillation (VF), a chaotic rhythm with no effective cardiac
output. The definitive treatment for VF is immediate unsynchronized defibrillation combined
with high-quality CPR. Epinephrine is given to improve coronary perfusion pressure but does
not convert the rhythm.
Question 14: A patient with a permanent ventricular pacemaker has an EKG showing a pacing
spike that is not followed by a QRS complex. What is this pacemaker malfunction called? A.
Failure to pace. B. Failure to capture. C. Failure to sense. D. Undersensing.
CORRECT ANSWER: B. Failure to capture. Rationale: Failure to capture occurs when the
pacemaker generates an electrical impulse (seen as a pacing spike), but the myocardium does
not depolarize in response (no subsequent P wave or QRS complex). Causes include lead
dislodgement, myocardial ischemia, electrolyte imbalances, or increased pacing threshold.
Question 15: A patient's EKG shows a pacing spike occurring immediately after a patient's
intrinsic QRS complex. What type of pacemaker malfunction is this? A. Failure to pace. B.
Failure to capture. C. Failure to sense (Undersensing). D. Oversensing.
