CSCT EXAM ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+
GRADED 100% VERIFIED) LATEST VERSION 2025!!
Question 1
Which of the following ECG changes is a definitive indicator of an absolute contraindication to
immediately stop an Exercise Tolerance Test (ETT)?
A) Development of non-sustained ventricular tachycardia (NSVT).
B) ST-segment depression of 2.0 mm at a heart rate of 130 bpm.
C) A drop in systolic blood pressure (SBP) of more than 10 mmHg from baseline, accompanied
by other signs of ischemia.
D) Patient reporting moderate (Level 3) angina (typical chest pain).
E) T-wave inversion in leads V5 and V6.
Correct Answer: C) A drop in systolic blood pressure (SBP) of more than 10 mmHg from
baseline, accompanied by other signs of ischemia.
Rationale: A drop in SBP of
≥
10 mmHg below baseline SBP (or below the previous stage's SBP) that occurs despite an
increase in workload, especially when accompanied by other evidence of ischemia (like
severe chest pain or syncope), is an absolute indication for terminating an ETT. This
signifies profound ventricular dysfunction and inadequate cardiac output, presenting an
immediate safety risk to the patient. While NSVT (A) or 2.0 mm ST depression (B) are
significant, the SBP drop is considered a more critical and absolute stop point by most
guidelines. Severe Angina (D) is also an absolute indication, but the SBP drop is another
key physiological marker.
Question 2
What is the standard formula used to calculate the Corrected QT Interval (QTc) on an ECG, as
referenced in CSCT guidelines?
A) QTc = QT interval
÷
√𝑅𝑅
(Bazett's Formula)
B) QTc = QT interval
÷
(RR interval
×
, 2
1.1
)
C) QTc = QT interval
÷
(RR interval
÷
1.05
)
D) QTc = QT interval
÷
3
√𝑅𝑅
(Fridericia's Formula)
E) QTc = QT interval
÷
(RR interval +
0.07
)
Correct Answer: A) QTc = QT interval
÷
√𝑅𝑅
(Bazett's Formula)
Rationale: Bazett's Formula (
𝑄𝑇𝑐 = 𝑄𝑇/√𝑅𝑅
, 3
) is the most widely recognized and historically used formula for heart rate correction of
the QT interval in clinical and examination settings, including those outlined by CSCT
guidelines for normal ECG measurements. A QTc value greater than 450 ms in men and
460 ms in women is generally considered prolonged and is a risk factor for Torsades de
Pointes.
Question 3
In the context of standard 12-lead ECG placement, which electrode is designated as
the neutral/ground electrode and is typically placed on a non-recording limb?
A) Left Arm (LA)
B) Right Arm (RA)
C) Right Leg (RL)
D) Left Leg (LL)
E) V1-V6 chest leads
Correct Answer: C) Right Leg (RL)
Rationale: The Right Leg (RL) electrode serves as the ground or neutral electrode for the
standard 12-lead ECG system. Its purpose is to minimize electrical interference (like 60-
cycle artifact) and serve as a reference point for the machine, ensuring the other leads can
accurately record the heart's electrical activity. It is not used to calculate any of the
standard leads.
Question 4
A patient presents with an ECG showing a regular narrow-complex tachycardia at a rate of 180
bpm. The P waves are not clearly visible but appear to be buried within the QRS complex. This
is most consistent with:
A) Atrial Fibrillation (AF) with Rapid Ventricular Response (RVR)
B) Ventricular Tachycardia (VT)
C) Atrial Flutter with 2:1 conduction
D) AV Nodal Reentrant Tachycardia (AVNRT)
E) Multifocal Atrial Tachycardia (MAT)
Correct Answer: D) AV Nodal Reentrant Tachycardia (AVNRT)
Rationale: AVNRT is a common type of Supraventricular Tachycardia (SVT). It is
characterized by a regular, narrow-complex rhythm (since the ventricles are depolarized
normally) and a rapid rate (typically 150-250 bpm). In the most common "slow-fast" form,
the atrial and ventricular activation occurs nearly simultaneously, resulting in P waves
being obscured, or buried within, the QRS complex (sometimes appearing as "pseudo-R
prime" or "pseudo-S" waves).
Question 5
What is the primary action of a Class I antiarrhythmic drug (e.g., Flecainide) on the cardiac
, 4
action potential?
A) Blocking
Ca2+
(calcium) channels
B) Prolonging the refractory period by blocking
K+
(potassium) channels
C) Blocking
Na+
(sodium) channels in the fast-response cells
D) Acting as a beta-adrenergic receptor antagonist (beta-blocker)
E) Increasing the slope of Phase 4 spontaneous depolarization
Correct Answer: C) Blocking
Na+
(sodium) channels in the fast-response cells
Rationale: Class I antiarrhythmic drugs are membrane-stabilizing agents that selectively
block the fast inward
Na+
current (Phase 0) in the myocardial working cells (ventricular and atrial myocytes). This
slows the rate of depolarization, thus slowing conduction velocity in the atria, ventricles,
and His-Purkinje system. This property makes them useful for treating and preventing fast
arrhythmias, though some subclasses (like Ic) carry a significant proarrhythmic risk.
Question 6
When performing an Exercise Tolerance Test (ETT) on a patient with a baseline Left Bundle
Branch Block (LBBB), the appearance of ST-segment changes for the diagnosis of ischemia is
considered:
A) Highly reliable, as LBBB does not interfere with ST-segment analysis.
B) Reliable only if the ST-segment elevation is
> 2.0
mm.
C) Not reliable for diagnosis of ischemia due to repolarization abnormalities caused by LBBB.
GRADED 100% VERIFIED) LATEST VERSION 2025!!
Question 1
Which of the following ECG changes is a definitive indicator of an absolute contraindication to
immediately stop an Exercise Tolerance Test (ETT)?
A) Development of non-sustained ventricular tachycardia (NSVT).
B) ST-segment depression of 2.0 mm at a heart rate of 130 bpm.
C) A drop in systolic blood pressure (SBP) of more than 10 mmHg from baseline, accompanied
by other signs of ischemia.
D) Patient reporting moderate (Level 3) angina (typical chest pain).
E) T-wave inversion in leads V5 and V6.
Correct Answer: C) A drop in systolic blood pressure (SBP) of more than 10 mmHg from
baseline, accompanied by other signs of ischemia.
Rationale: A drop in SBP of
≥
10 mmHg below baseline SBP (or below the previous stage's SBP) that occurs despite an
increase in workload, especially when accompanied by other evidence of ischemia (like
severe chest pain or syncope), is an absolute indication for terminating an ETT. This
signifies profound ventricular dysfunction and inadequate cardiac output, presenting an
immediate safety risk to the patient. While NSVT (A) or 2.0 mm ST depression (B) are
significant, the SBP drop is considered a more critical and absolute stop point by most
guidelines. Severe Angina (D) is also an absolute indication, but the SBP drop is another
key physiological marker.
Question 2
What is the standard formula used to calculate the Corrected QT Interval (QTc) on an ECG, as
referenced in CSCT guidelines?
A) QTc = QT interval
÷
√𝑅𝑅
(Bazett's Formula)
B) QTc = QT interval
÷
(RR interval
×
, 2
1.1
)
C) QTc = QT interval
÷
(RR interval
÷
1.05
)
D) QTc = QT interval
÷
3
√𝑅𝑅
(Fridericia's Formula)
E) QTc = QT interval
÷
(RR interval +
0.07
)
Correct Answer: A) QTc = QT interval
÷
√𝑅𝑅
(Bazett's Formula)
Rationale: Bazett's Formula (
𝑄𝑇𝑐 = 𝑄𝑇/√𝑅𝑅
, 3
) is the most widely recognized and historically used formula for heart rate correction of
the QT interval in clinical and examination settings, including those outlined by CSCT
guidelines for normal ECG measurements. A QTc value greater than 450 ms in men and
460 ms in women is generally considered prolonged and is a risk factor for Torsades de
Pointes.
Question 3
In the context of standard 12-lead ECG placement, which electrode is designated as
the neutral/ground electrode and is typically placed on a non-recording limb?
A) Left Arm (LA)
B) Right Arm (RA)
C) Right Leg (RL)
D) Left Leg (LL)
E) V1-V6 chest leads
Correct Answer: C) Right Leg (RL)
Rationale: The Right Leg (RL) electrode serves as the ground or neutral electrode for the
standard 12-lead ECG system. Its purpose is to minimize electrical interference (like 60-
cycle artifact) and serve as a reference point for the machine, ensuring the other leads can
accurately record the heart's electrical activity. It is not used to calculate any of the
standard leads.
Question 4
A patient presents with an ECG showing a regular narrow-complex tachycardia at a rate of 180
bpm. The P waves are not clearly visible but appear to be buried within the QRS complex. This
is most consistent with:
A) Atrial Fibrillation (AF) with Rapid Ventricular Response (RVR)
B) Ventricular Tachycardia (VT)
C) Atrial Flutter with 2:1 conduction
D) AV Nodal Reentrant Tachycardia (AVNRT)
E) Multifocal Atrial Tachycardia (MAT)
Correct Answer: D) AV Nodal Reentrant Tachycardia (AVNRT)
Rationale: AVNRT is a common type of Supraventricular Tachycardia (SVT). It is
characterized by a regular, narrow-complex rhythm (since the ventricles are depolarized
normally) and a rapid rate (typically 150-250 bpm). In the most common "slow-fast" form,
the atrial and ventricular activation occurs nearly simultaneously, resulting in P waves
being obscured, or buried within, the QRS complex (sometimes appearing as "pseudo-R
prime" or "pseudo-S" waves).
Question 5
What is the primary action of a Class I antiarrhythmic drug (e.g., Flecainide) on the cardiac
, 4
action potential?
A) Blocking
Ca2+
(calcium) channels
B) Prolonging the refractory period by blocking
K+
(potassium) channels
C) Blocking
Na+
(sodium) channels in the fast-response cells
D) Acting as a beta-adrenergic receptor antagonist (beta-blocker)
E) Increasing the slope of Phase 4 spontaneous depolarization
Correct Answer: C) Blocking
Na+
(sodium) channels in the fast-response cells
Rationale: Class I antiarrhythmic drugs are membrane-stabilizing agents that selectively
block the fast inward
Na+
current (Phase 0) in the myocardial working cells (ventricular and atrial myocytes). This
slows the rate of depolarization, thus slowing conduction velocity in the atria, ventricles,
and His-Purkinje system. This property makes them useful for treating and preventing fast
arrhythmias, though some subclasses (like Ic) carry a significant proarrhythmic risk.
Question 6
When performing an Exercise Tolerance Test (ETT) on a patient with a baseline Left Bundle
Branch Block (LBBB), the appearance of ST-segment changes for the diagnosis of ischemia is
considered:
A) Highly reliable, as LBBB does not interfere with ST-segment analysis.
B) Reliable only if the ST-segment elevation is
> 2.0
mm.
C) Not reliable for diagnosis of ischemia due to repolarization abnormalities caused by LBBB.
