CCT PRACTICE TEST WITH QUESTIONS AND
ANSWERS
1. Which cardiac chamber pumps deoxygenated blood to the lungs?
a. Right atrium
b. Right ventricle.
c. Left atrium
d. Left ventricle - ANSWER 1. B: The right ventricle sends the deoxygenated
blood it receives from the right atrium to the lungs. The right atrium circulates
deoxygenated blood from the body to the right ventricle. The left atrium transports
oxygenated blood from the lungs into the left ventricle. The left ventricle
distributes oxygenated blood throughout the body.
2. Which lead is most influenced by respiration?
a. V2
b. V4
c. Lead III
d. Lead I: ANSWER 2. C: Lead III is the most impacted by respiration, hence the
waveforms may vary based on the respiratory cycle. As a result, a Q wave that
arises just in lead III and is not accompanied by other similar changes in other leads
is insignificant.
3. Which of the following is the right order in which action potentials are
transmitted through the heart?"
a. SA node to AV node, then bundle branches to Purkinje fibers.
b. Bundle branches lead to Purkinje fibers, which lead to the SA node and then the
AV node.
,c. Purkinje fibers connect to the SA node, then to the bundle branches, and finally
to the AV node.
d. AV node → SA node → bundle branches → Purkinje fibers - ANSWER 3. A: An
action potential travels through the heart from the sinoatrial (SA) node to the
atrioventricular (AV) node, the bundle branches, and finally the Purkinje fibers.
4. What form of heart block is visible in the following electrocardiogram (ECG)
strip?"
a. First-degree heart block.
b. Second-degree heart block, type 1.
c. Second-degree heart block (type 2)
d. Third-degree heart block - ANSWER 4. B: The ECG shown shows a
second-degree heart block, type 1. This rhythm is also known as Mobitz I or
Wenckebach. With this heart block, the PR interval grows longer with each beat,
finally resulting in a P wave but no QRS. After the skipped beat, the rhythm begins
again. A first-degree heart block occurs when the PR interval exceeds 0.2 seconds
but remains constant and the QRS does not decline. A second-degree heart block,
also known as Mobitz II, occurs when the QRS fails to appear following a P wave.
The ratio of P waves to QRS complexes is generally stable, and this rhythm lacks
the growing PR interval seen in the Mobitz I block. A third-degree heart block,
sometimes known as a complete heart block, occurs when the atria and ventricles
beat independently of each other.
5. When calibrating an ECG machine, what is the standard size of the calibration
mark denoting the equipment's sensitivity?
a. 5 mm in height.
b. 10 mm in height.
c. 15 mm in height.
, d. 20 mm in height - ANSWER 5. B: The calibration mark denoting the sensitivity
of the ECG should be 10 mm tall (two huge squares). This indicator is typically
visible on the left side of the page, at the start of each line of the ECG. When
adjusted appropriately, the trace will show a 10 mm deflection for every millivolt
measured from the patient.
6. Which of the following describes the mechanism of action of nitrates?
a. Reduce the reactivity of the heart to the sympathetic nervous system.
b. Lower your heart rate.
c. Reduces cardiac contractility.
d. ANSWER 6: Dilation of coronary arteries. D: Nitrates are effective in the
prevention and treatment of angina. They function by dilating the coronary arteries,
boosting blood flow to the heart. They dilate peripheral veins and, in higher doses,
other peripheral arteries, therefore lowering preload and afterload. Beta-blockers
reduce the heart's reactivity to the sympathetic nervous system. Calcium channel
blockers, beta-blockers, and other drugs reduce cardiac contractility and heart rate.
7. Which phase of the action potential in fast ANSWER cardiac tissues involves
rapid depolarization and bringing the resting cell to the threshold?
a. Phase 0
b. Phase 1
c. Phase 2
d. Phase 3: ANSWER 7. A: Phase 0 involves fast depolarization of the cell to
threshold, which activates voltage-dependent sodium channels. Phase 1 consists of
a minor "notch" of repolarization induced mostly by the activation of transitory
potassium currents (potassium leaving the cell) and a subsequent quick reduction in
the sodium current. Phase 2 is a plateau phase in which "late" calcium and, to a
lesser extent, sodium currents counteract the influence of potassium currents,
briefly stabilizing the membrane potential. Repolarization and restoration to resting
ANSWERS
1. Which cardiac chamber pumps deoxygenated blood to the lungs?
a. Right atrium
b. Right ventricle.
c. Left atrium
d. Left ventricle - ANSWER 1. B: The right ventricle sends the deoxygenated
blood it receives from the right atrium to the lungs. The right atrium circulates
deoxygenated blood from the body to the right ventricle. The left atrium transports
oxygenated blood from the lungs into the left ventricle. The left ventricle
distributes oxygenated blood throughout the body.
2. Which lead is most influenced by respiration?
a. V2
b. V4
c. Lead III
d. Lead I: ANSWER 2. C: Lead III is the most impacted by respiration, hence the
waveforms may vary based on the respiratory cycle. As a result, a Q wave that
arises just in lead III and is not accompanied by other similar changes in other leads
is insignificant.
3. Which of the following is the right order in which action potentials are
transmitted through the heart?"
a. SA node to AV node, then bundle branches to Purkinje fibers.
b. Bundle branches lead to Purkinje fibers, which lead to the SA node and then the
AV node.
,c. Purkinje fibers connect to the SA node, then to the bundle branches, and finally
to the AV node.
d. AV node → SA node → bundle branches → Purkinje fibers - ANSWER 3. A: An
action potential travels through the heart from the sinoatrial (SA) node to the
atrioventricular (AV) node, the bundle branches, and finally the Purkinje fibers.
4. What form of heart block is visible in the following electrocardiogram (ECG)
strip?"
a. First-degree heart block.
b. Second-degree heart block, type 1.
c. Second-degree heart block (type 2)
d. Third-degree heart block - ANSWER 4. B: The ECG shown shows a
second-degree heart block, type 1. This rhythm is also known as Mobitz I or
Wenckebach. With this heart block, the PR interval grows longer with each beat,
finally resulting in a P wave but no QRS. After the skipped beat, the rhythm begins
again. A first-degree heart block occurs when the PR interval exceeds 0.2 seconds
but remains constant and the QRS does not decline. A second-degree heart block,
also known as Mobitz II, occurs when the QRS fails to appear following a P wave.
The ratio of P waves to QRS complexes is generally stable, and this rhythm lacks
the growing PR interval seen in the Mobitz I block. A third-degree heart block,
sometimes known as a complete heart block, occurs when the atria and ventricles
beat independently of each other.
5. When calibrating an ECG machine, what is the standard size of the calibration
mark denoting the equipment's sensitivity?
a. 5 mm in height.
b. 10 mm in height.
c. 15 mm in height.
, d. 20 mm in height - ANSWER 5. B: The calibration mark denoting the sensitivity
of the ECG should be 10 mm tall (two huge squares). This indicator is typically
visible on the left side of the page, at the start of each line of the ECG. When
adjusted appropriately, the trace will show a 10 mm deflection for every millivolt
measured from the patient.
6. Which of the following describes the mechanism of action of nitrates?
a. Reduce the reactivity of the heart to the sympathetic nervous system.
b. Lower your heart rate.
c. Reduces cardiac contractility.
d. ANSWER 6: Dilation of coronary arteries. D: Nitrates are effective in the
prevention and treatment of angina. They function by dilating the coronary arteries,
boosting blood flow to the heart. They dilate peripheral veins and, in higher doses,
other peripheral arteries, therefore lowering preload and afterload. Beta-blockers
reduce the heart's reactivity to the sympathetic nervous system. Calcium channel
blockers, beta-blockers, and other drugs reduce cardiac contractility and heart rate.
7. Which phase of the action potential in fast ANSWER cardiac tissues involves
rapid depolarization and bringing the resting cell to the threshold?
a. Phase 0
b. Phase 1
c. Phase 2
d. Phase 3: ANSWER 7. A: Phase 0 involves fast depolarization of the cell to
threshold, which activates voltage-dependent sodium channels. Phase 1 consists of
a minor "notch" of repolarization induced mostly by the activation of transitory
potassium currents (potassium leaving the cell) and a subsequent quick reduction in
the sodium current. Phase 2 is a plateau phase in which "late" calcium and, to a
lesser extent, sodium currents counteract the influence of potassium currents,
briefly stabilizing the membrane potential. Repolarization and restoration to resting
