SCST-D1 SCST Diploma in ECG Interpretation Exam – v v v v v v v
Practice Questions And Correct Answers (Verified An
v v v v v v v
swers) Plus Rationales 2026/2027 Q&A | Instant Dow
v v v v v v v
nload Pdf v
1. Which ECG lead is most commonly used to monitor rhythm during clinical
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practice?
A. Lead I v
B. Lead II v
C. Lead III v
D. aVR
Lead II best aligns with the electrical axis of the heart, providing clear P waves and QR
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S complexes.
v
2. The P wave represents:
v v v
A. Ventricular depolarization v
B. Ventricular repolarization v
C. Atrial depolarization v
D. Atrial repolarization v
The P wave corresponds to atrial depolarization.
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3. A normal PR interval is:
v v v v
A. <0.08 sec v
B. 0.12–0.20 sec v
C. 0.20–0.28 sec v
D. >0.28 sec v
Normal PR interval is between 120–200 ms.
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4. The QRS complex width should normally be:
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,A. >0.14 sec v
B. <0.12 sec v
C. 0.12–0.16 sec v
D. >0.20 sec v
A normal QRS is narrow (<120 ms).
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5. Which electrolyte abnormality is most associated with peaked T waves?
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A. Hypocalcemia
B. Hypomagnesemia
C. Hyperkalemia
D. Hypernatremia
Excess potassium causes tall, peaked T waves.
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6. The ST segment elevation is classically associated with:
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A. Pericarditis
B. Ventricular hypertrophy v
C. Myocardial infarction v
D. Atrial fibrillation
v
ST elevation is a hallmark of acute myocardial injury.
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7. The QT interval represents:
v v v
A. Total ventricular depolarization and repolarization
v v v v
B. Atrial depolarization
v
C. PR conduction
v
D. SA node delay
v v
QT interval includes QRS, ST, and T wave—ventricular activity.
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8. Atrial fibrillation is characterized by:
v v v v
A. Sawtooth flutter waves v v
B. Irregularly irregular rhythm with absent P waves
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C. Regular narrow QRS tachycardiav v v
D. Wide QRS complexesv v
AF shows fibrillatory baseline and irregularly irregular ventricular response.
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, 9. Which lead is most useful for detecting atrial activity?
v v v v v v v v
A. aVR
B. V1
C. Lead II v
D. V6
Lead II provides a clear view of atrial activity (P waves).
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10. Mobitz type I AV block is also called:
v v v v v v v
A. High-grade block v
B. Mobitz II block v v
C. Wenckebach block v
D. Bundle branch block v v
Progressive PR prolongation with dropped beat = Wenckebach.
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11. The intrinsic rate of the SA node is:
v v v v v v v
A. 20–40 bpm v
B. 40–60 bpm v
C. 60–100 bpm v
D. 100–120 bpm v
SA node normally fires 60–100 times per minute.
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12. The paper speed on a standard ECG is:
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A. 10 mm/sec
v
B. 25 mm/sec
v
C. 50 mm/sec
v
D. 100 mm/sec
v
Standard ECG is recorded at 25 mm per second.
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13. Which wave represents ventricular repolarization?
v v v v
A. P
B. QRS
Practice Questions And Correct Answers (Verified An
v v v v v v v
swers) Plus Rationales 2026/2027 Q&A | Instant Dow
v v v v v v v
nload Pdf v
1. Which ECG lead is most commonly used to monitor rhythm during clinical
v v v v v v v v v v v v v
practice?
A. Lead I v
B. Lead II v
C. Lead III v
D. aVR
Lead II best aligns with the electrical axis of the heart, providing clear P waves and QR
v v v v v v v v v v v v v v v v
S complexes.
v
2. The P wave represents:
v v v
A. Ventricular depolarization v
B. Ventricular repolarization v
C. Atrial depolarization v
D. Atrial repolarization v
The P wave corresponds to atrial depolarization.
v v v v v v
3. A normal PR interval is:
v v v v
A. <0.08 sec v
B. 0.12–0.20 sec v
C. 0.20–0.28 sec v
D. >0.28 sec v
Normal PR interval is between 120–200 ms.
v v v v v v
4. The QRS complex width should normally be:
v v v v v v
,A. >0.14 sec v
B. <0.12 sec v
C. 0.12–0.16 sec v
D. >0.20 sec v
A normal QRS is narrow (<120 ms).
v v v v v v
5. Which electrolyte abnormality is most associated with peaked T waves?
v v v v v v v v v
A. Hypocalcemia
B. Hypomagnesemia
C. Hyperkalemia
D. Hypernatremia
Excess potassium causes tall, peaked T waves.
v v v v v v
6. The ST segment elevation is classically associated with:
v v v v v v v
A. Pericarditis
B. Ventricular hypertrophy v
C. Myocardial infarction v
D. Atrial fibrillation
v
ST elevation is a hallmark of acute myocardial injury.
v v v v v v v v
7. The QT interval represents:
v v v
A. Total ventricular depolarization and repolarization
v v v v
B. Atrial depolarization
v
C. PR conduction
v
D. SA node delay
v v
QT interval includes QRS, ST, and T wave—ventricular activity.
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8. Atrial fibrillation is characterized by:
v v v v
A. Sawtooth flutter waves v v
B. Irregularly irregular rhythm with absent P waves
v v v v v v
C. Regular narrow QRS tachycardiav v v
D. Wide QRS complexesv v
AF shows fibrillatory baseline and irregularly irregular ventricular response.
v v v v v v v v
, 9. Which lead is most useful for detecting atrial activity?
v v v v v v v v
A. aVR
B. V1
C. Lead II v
D. V6
Lead II provides a clear view of atrial activity (P waves).
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10. Mobitz type I AV block is also called:
v v v v v v v
A. High-grade block v
B. Mobitz II block v v
C. Wenckebach block v
D. Bundle branch block v v
Progressive PR prolongation with dropped beat = Wenckebach.
v v v v v v v
11. The intrinsic rate of the SA node is:
v v v v v v v
A. 20–40 bpm v
B. 40–60 bpm v
C. 60–100 bpm v
D. 100–120 bpm v
SA node normally fires 60–100 times per minute.
v v v v v v v
12. The paper speed on a standard ECG is:
v v v v v v v
A. 10 mm/sec
v
B. 25 mm/sec
v
C. 50 mm/sec
v
D. 100 mm/sec
v
Standard ECG is recorded at 25 mm per second.
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13. Which wave represents ventricular repolarization?
v v v v
A. P
B. QRS
