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Section 1: Basic Principles & Sinus Rhythms (Questions 1-50)
1. The normal rate for a sinus rhythm is:
• A) 40-60 bpm
• B) 60-100 bpm
• C) 100-150 bpm
• D) 60-100 bpm
Rationale: Normal sinus rhythm is defined by a rate of 60-100 beats per minute with a
regular rhythm and normal P waves.
2. A patient has a heart rate of 52 bpm, regular rhythm, and normal P waves.
This rhythm is best described as:
• A) Normal Sinus Rhythm
• B) Sinus Bradycardia
• C) Sinus Tachycardia
• D) First-Degree AV Block
Rationale: Sinus bradycardia is characterized by a sinus rate of less than 60 bpm.
3. The normal PR interval duration is:
• A) 0.04 - 0.10 seconds
• B) 0.12 - 0.20 seconds
• C) 0.20 - 0.30 seconds
• D) >0.30 seconds
Rationale: The normal PR interval, measured from the start of the P wave to the start of
the QRS, is 0.12 to 0.20 seconds (3 to 5 small boxes).
, 4. In sinus tachycardia, the rate typically does not exceed which value in a
healthy adult?
• A) 100 bpm
• B) 120 bpm
• C) 150 bpm
• D) 180 bpm
Rationale: Sinus tachycardia is generally defined as a sinus rhythm between 100 and
150 bpm, though it can be higher with extreme stress or in children.
5. To determine ventricular rate for a regular rhythm, you should count the
number of:
• A) P waves in a 6-second strip and multiply by 10
• B) R waves in a 6-second strip and multiply by 10
• C) Large squares between two R waves and divide 300 by that number
• D) Small squares between two P waves and divide 1500 by that number
Rationale: For regular rhythms, the "300 method" is accurate. Count the number of
large boxes between two R waves and divide 300 by that number.
6. A patient is anxious, has a HR of 130 bpm, and a regular rhythm. The ECG
shows normal P waves. What is the most likely rhythm?
• A) Atrial Fibrillation
• B) Ventricular Tachycardia
• C) Sinus Tachycardia
• D) SVT
Rationale: Sinus tachycardia is a fast rhythm originating from the sinus node. The
presence of normal P waves before each QRS confirms this.
7. What is the normal duration for a QRS complex?
• A) 0.04 - 0.10 seconds
• B) 0.08 - 0.12 seconds
• C) 0.12 - 0.20 seconds
, • D) >0.12 seconds
Rationale: A narrow QRS complex is less than 0.12 seconds (3 small boxes), indicating
the impulse traveled through the normal conduction pathway.
8. If the R-R intervals on a rhythm strip are all equal, the rhythm is considered:
• A) Regular
• B) Irregular
• C) Irregularly irregular
• D) Normal
Rationale: Regularity is determined by measuring the R-R intervals. If they are
consistent, the rhythm is regular.
9. A patient's monitor shows a HR of 110 bpm and a regular rhythm. The P
waves are upright and consistent. This is:
• A) Junctional Tachycardia
• B) Atrial Tachycardia
• C) Sinus Bradycardia
• D) Sinus Tachycardia
Rationale: The rhythm fits all criteria for a sinus rhythm (upright P waves, normal PR,
narrow QRS) but the rate is >100 bpm, making it sinus tachycardia.
10. Which of the following is NOT a characteristic of Sinus Arrhythmia?
• A) Irregular rhythm
• B) Rate between 60-100 bpm
• C) P waves present and upright
• D) Rate changes with the respiratory cycle
Rationale: A sinus arrhythmia is an irregularity in the sinus rhythm that often varies
with respiration. The rate itself remains within normal limits.
11. On a standard ECG paper, the horizontal axis measures:
• A) Amplitude (voltage)
• B) Time (duration)