Dysrhythmia & ACLS Study Guide 2025
Comprehensive Exam Preparation with 100 Questions and Verified
Answers
Introduction
This study guide follows the latest American Heart Association (AHA)
guidelines for Advanced Cardiovascular Life Support (ACLS) and
dysrhythmia management. All answers are verified according to 2025
standards.
SECTION 1: BASIC RHYTHM RECOGNITION (Questions 1-20)
1. Q: What is the normal heart rate range for adults? A: 60-100 beats
per minute. Rates below 60 are bradycardia, above 100 are tachycardia.
2. Q: What are the characteristics of normal sinus rhythm? A: Rate 60-
100 bpm, regular rhythm, P wave before each QRS, PR interval 0.12-
0.20 seconds, QRS width <0.12 seconds.
3. Q: How do you calculate heart rate from an ECG strip? A: Count the
number of QRS complexes in 6 seconds and multiply by 10, or use the
300 rule (300 divided by number of large boxes between R waves).
4. Q: What defines sinus bradycardia? A: Heart rate less than 60 bpm
with normal sinus rhythm characteristics (P wave before each QRS,
regular rhythm).
5. Q: What are the criteria for sinus tachycardia? A: Heart rate greater
than 100 bpm with normal sinus rhythm characteristics, gradual onset
and termination.
, 6. Q: How can you differentiate between atrial flutter and atrial
fibrillation? A: Atrial flutter has organized "sawtooth" flutter waves at
250-350 bpm; atrial fibrillation has chaotic, irregular atrial activity with
no identifiable P waves.
7. Q: What is the typical ventricular response rate in untreated atrial
fibrillation? A: 120-180 beats per minute, irregularly irregular rhythm.
8. Q: What characterizes first-degree AV block? A: PR interval greater
than 0.20 seconds (5 small boxes) with all P waves conducted to
ventricles.
9. Q: Describe Mobitz Type I (Wenckebach) second-degree AV block. A:
Progressive PR interval lengthening until a P wave is not conducted,
then the cycle repeats.
10. Q: What is the hallmark of Mobitz Type II second-degree AV block?
A: Constant PR intervals with intermittent non-conducted P waves,
often with wide QRS complexes.
11. Q: How do you identify third-degree (complete) heart block? A:
Complete AV dissociation with independent atrial and ventricular
rhythms, more P waves than QRS complexes.
12. Q: What defines ventricular tachycardia? A: Three or more
consecutive ventricular beats at a rate >100 bpm, wide QRS complexes
(>0.12 seconds).
13. Q: How do you differentiate VT from SVT with aberrancy? A: VT
typically has AV dissociation, capture beats, fusion beats, and
concordance in precordial leads.
Comprehensive Exam Preparation with 100 Questions and Verified
Answers
Introduction
This study guide follows the latest American Heart Association (AHA)
guidelines for Advanced Cardiovascular Life Support (ACLS) and
dysrhythmia management. All answers are verified according to 2025
standards.
SECTION 1: BASIC RHYTHM RECOGNITION (Questions 1-20)
1. Q: What is the normal heart rate range for adults? A: 60-100 beats
per minute. Rates below 60 are bradycardia, above 100 are tachycardia.
2. Q: What are the characteristics of normal sinus rhythm? A: Rate 60-
100 bpm, regular rhythm, P wave before each QRS, PR interval 0.12-
0.20 seconds, QRS width <0.12 seconds.
3. Q: How do you calculate heart rate from an ECG strip? A: Count the
number of QRS complexes in 6 seconds and multiply by 10, or use the
300 rule (300 divided by number of large boxes between R waves).
4. Q: What defines sinus bradycardia? A: Heart rate less than 60 bpm
with normal sinus rhythm characteristics (P wave before each QRS,
regular rhythm).
5. Q: What are the criteria for sinus tachycardia? A: Heart rate greater
than 100 bpm with normal sinus rhythm characteristics, gradual onset
and termination.
, 6. Q: How can you differentiate between atrial flutter and atrial
fibrillation? A: Atrial flutter has organized "sawtooth" flutter waves at
250-350 bpm; atrial fibrillation has chaotic, irregular atrial activity with
no identifiable P waves.
7. Q: What is the typical ventricular response rate in untreated atrial
fibrillation? A: 120-180 beats per minute, irregularly irregular rhythm.
8. Q: What characterizes first-degree AV block? A: PR interval greater
than 0.20 seconds (5 small boxes) with all P waves conducted to
ventricles.
9. Q: Describe Mobitz Type I (Wenckebach) second-degree AV block. A:
Progressive PR interval lengthening until a P wave is not conducted,
then the cycle repeats.
10. Q: What is the hallmark of Mobitz Type II second-degree AV block?
A: Constant PR intervals with intermittent non-conducted P waves,
often with wide QRS complexes.
11. Q: How do you identify third-degree (complete) heart block? A:
Complete AV dissociation with independent atrial and ventricular
rhythms, more P waves than QRS complexes.
12. Q: What defines ventricular tachycardia? A: Three or more
consecutive ventricular beats at a rate >100 bpm, wide QRS complexes
(>0.12 seconds).
13. Q: How do you differentiate VT from SVT with aberrancy? A: VT
typically has AV dissociation, capture beats, fusion beats, and
concordance in precordial leads.
