CCT ACTUAL TEST FULL QUESTIONS AND
CORRECT ANSWERS EXAMPREP STUDY
SHEET
●● 2. Which lead is the most affected by respiration?
a. V2
b. V4
c. Lead III
d. Lead I
Answer: 2. C: Lead III is the most affected by respiration, and therefore
the waveforms may look different depending on the respiratory cycle.
Because of this, a Q wave that only appears in lead III and is not
associated with other corresponding changes in other leads is not
significant.
●● 3. Which of the following is the correct sequence by which action
potentials are conducted through the heart?"
a. SA node → AV node → bundle branches → Purkinje fibers
b. Bundle branches → Purkinje fibers → SA node → AV node
c. Purkinje fibers → SA node → bundle branches → AV node
d. AV node → SA node → bundle branches → Purkinje fibers
,Answer: 3. A: The sequence by which an action potential is conducted
through the heart is from the sinoatrial (SA) node to the atrioventricular
(AV) node to the bundle branches and then to the Purkinje fibers.
●● 4. What type of heart block is seen 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 pictured ECG is a second-degree heart block, type 1.
This rhythm is also called Mobitz I or Wenckebach. With this heart
block the PR interval gets longer with each beat until eventually a P
wave occurs, but a QRS does not follow (a beat is skipped). After the
skipped beat, the pattern starts over again. A first-degree heart block
occurs when the PR interval is longer than 0.2 seconds, but the PR
interval generally remains constant and the QRS is not dropped. A
second-degree heart block, type 2, also called Mobitz II, is apparent
when the QRS suddenly fails to show up after a P wave. A fairly
consistent ratio of P waves to QRS complexes is common, and this
rhythm lacks the increasing PR interval that is seen in the Mobitz I
block. A third-degree heart block is also called a complete heart block
and the atria and ventricles beat independently of one another.
, ●● 5. When calibrating an ECG machine, what is the standard size of
the calibration mark representing the sensitivity of the ECG machine?
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 representing the sensitivity of the
ECG should be 10 mm in height (two large squares). This mark is
usually found on the left side of the page at the beginning of each line of
the ECG. When this is set correctly it means that for every millivolt
measured from the patient, a deflection of 10 mm will be recorded on
the trace.
●● 6. Which of the following is the mechanism of action of nitrates?
a. Decrease the responsiveness of heart to the sympathetic nervous
system
b. Lower the heart rate
c. Decrease cardiac contractility
d. Dilation of coronary arteries
Answer: 6. D: Nitrates are useful for the prevention and treatment of
angina. They work by dilating the coronary arteries and thus increasing
the blood flow to the heart. They dilate peripheral veins, and, in higher
doses, other peripheral arteries, which decreases preload and afterload.
Beta-blockers decrease the responsiveness of the heart to the
sympathetic nervous system. Calcium channel blockers, beta-blockers,
CORRECT ANSWERS EXAMPREP STUDY
SHEET
●● 2. Which lead is the most affected by respiration?
a. V2
b. V4
c. Lead III
d. Lead I
Answer: 2. C: Lead III is the most affected by respiration, and therefore
the waveforms may look different depending on the respiratory cycle.
Because of this, a Q wave that only appears in lead III and is not
associated with other corresponding changes in other leads is not
significant.
●● 3. Which of the following is the correct sequence by which action
potentials are conducted through the heart?"
a. SA node → AV node → bundle branches → Purkinje fibers
b. Bundle branches → Purkinje fibers → SA node → AV node
c. Purkinje fibers → SA node → bundle branches → AV node
d. AV node → SA node → bundle branches → Purkinje fibers
,Answer: 3. A: The sequence by which an action potential is conducted
through the heart is from the sinoatrial (SA) node to the atrioventricular
(AV) node to the bundle branches and then to the Purkinje fibers.
●● 4. What type of heart block is seen 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 pictured ECG is a second-degree heart block, type 1.
This rhythm is also called Mobitz I or Wenckebach. With this heart
block the PR interval gets longer with each beat until eventually a P
wave occurs, but a QRS does not follow (a beat is skipped). After the
skipped beat, the pattern starts over again. A first-degree heart block
occurs when the PR interval is longer than 0.2 seconds, but the PR
interval generally remains constant and the QRS is not dropped. A
second-degree heart block, type 2, also called Mobitz II, is apparent
when the QRS suddenly fails to show up after a P wave. A fairly
consistent ratio of P waves to QRS complexes is common, and this
rhythm lacks the increasing PR interval that is seen in the Mobitz I
block. A third-degree heart block is also called a complete heart block
and the atria and ventricles beat independently of one another.
, ●● 5. When calibrating an ECG machine, what is the standard size of
the calibration mark representing the sensitivity of the ECG machine?
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 representing the sensitivity of the
ECG should be 10 mm in height (two large squares). This mark is
usually found on the left side of the page at the beginning of each line of
the ECG. When this is set correctly it means that for every millivolt
measured from the patient, a deflection of 10 mm will be recorded on
the trace.
●● 6. Which of the following is the mechanism of action of nitrates?
a. Decrease the responsiveness of heart to the sympathetic nervous
system
b. Lower the heart rate
c. Decrease cardiac contractility
d. Dilation of coronary arteries
Answer: 6. D: Nitrates are useful for the prevention and treatment of
angina. They work by dilating the coronary arteries and thus increasing
the blood flow to the heart. They dilate peripheral veins, and, in higher
doses, other peripheral arteries, which decreases preload and afterload.
Beta-blockers decrease the responsiveness of the heart to the
sympathetic nervous system. Calcium channel blockers, beta-blockers,
