Echelon ECG & Cardiac Monitoring
ELON ECG & CARDIAC MONITORING | EXAM QUESTIONS
AND CORRECT ANSWERS | 2026/2027
ECHELON ECG & CARDIAC MONITORING
1. Stimulation of the sympathetic nerve fibers to the heart produces
which effect on heart rate?
A. Heart rate decreases
B. Heart rate increases
C. Heart rate is unchanged
D. Heart rate becomes irregular only
ANSWER : B. Heart rate increases
Sympathetic stimulation releases norepinephrine, which speeds SA node
firing and AV conduction (positive chronotropy).
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, Echelon ECG & Cardiac Monitoring
2. Which heart valves are classified as atrioventricular valves?
A. Aortic and pulmonic
B. Mitral and tricuspid
C. Tricuspid and pulmonic
D. Mitral and aortic
ANSWER : B. Mitral and tricuspid
The tricuspid (right) and mitral (left) valves sit between the atria and
ventricles.
3. Preload is most directly determined by:
A. The force of ventricular contraction
B. The resistance the left ventricle pumps against
C. The heart rate
D. The volume of blood returning to the ventricles at end-diastole
ANSWER : D. The volume of blood returning to the ventricles at end-
diastole
Preload is the stretch on ventricular fibers at end-diastole, governed
largely by venous return.
4. Afterload refers to:
A. The degree of myocardial fiber stretch
B. The amount of blood ejected per beat
C. The resistance the ventricle must overcome to eject blood
D. The volume of blood in the atria
ANSWER : C. The resistance the ventricle must overcome to eject
blood
Afterload is the pressure or resistance against which the ventricle pumps,
mainly systemic vascular resistance for the left ventricle.
5. Which coronary artery most commonly supplies the SA and AV
nodes?
A. Left circumflex artery
B. Left anterior descending artery
C. Right coronary artery
D. Left main coronary artery
ANSWER : C. Right coronary artery
In most people the RCA supplies both nodes, which is why inferior MIs
often cause bradycardia and AV block.
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, Echelon ECG & Cardiac Monitoring
6. The left anterior descending artery primarily supplies the:
A. Anterior wall of the left ventricle and anterior septum
B. Inferior wall of the left ventricle
C. Right ventricle
D. Posterior wall of the left atrium
ANSWER : A. Anterior wall of the left ventricle and anterior septum
The LAD perfuses the anterior LV and much of the septum; occlusion
produces changes in V1–V4.
7. The coronary arteries fill primarily during:
A. Ventricular systole
B. Ventricular diastole
C. Atrial systole only
D. Isovolumetric contraction
ANSWER : B. Ventricular diastole
During systole the contracting myocardium compresses the coronary
vessels, so most perfusion occurs in diastole.
8. Starling's law of the heart states that:
A. Greater myocardial stretch produces a stronger contraction, up to a
limit
B. Heart rate rises in response to low blood pressure
C. Afterload determines stroke volume exclusively
D. Stroke volume falls as preload rises
ANSWER : A. Greater myocardial stretch produces a stronger
contraction, up to a limit
Within physiologic limits, increased end-diastolic stretch increases the
force of contraction.
9. The property of cardiac cells to generate an impulse spontaneously is
called:
A. Excitability
B. Conductivity
C. Contractility
D. Automaticity
ANSWER : D. Automaticity
Automaticity allows pacemaker cells to depolarize without external
stimulation.
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, Echelon ECG & Cardiac Monitoring
10. The ability of cardiac cells to respond to a stimulus is called:
A. Automaticity
B. Conductivity
C. Excitability
D. Refractoriness
ANSWER : C. Excitability
Excitability (irritability) is the capacity of a cell to respond to an electrical
stimulus.
11. Depolarization of ventricular myocardial cells is triggered mainly
by the rapid influx of:
A. Magnesium
B. Potassium
C. Sodium
D. Chloride
ANSWER : C. Sodium
Phase 0 of the ventricular action potential is caused by fast sodium
channel opening.
12. The plateau phase (phase 2) of the ventricular action potential is
maintained largely by:
A. Sodium-potassium pump failure
B. Slow inward calcium current
C. Rapid sodium influx
D. Chloride efflux
ANSWER : B. Slow inward calcium current
Calcium entry balances potassium exit, prolonging the plateau and
supporting contraction.
13. The relative refractory period corresponds to which part of the
ECG?
A. The ST segment beginning
B. The downslope of the T wave
C. The PR segment
D. The P wave
ANSWER : B. The downslope of the T wave
A strong stimulus during the downslope of the T wave may depolarize
cells, which is the basis for R-on-T phenomenon.
Page 4 of 52
ELON ECG & CARDIAC MONITORING | EXAM QUESTIONS
AND CORRECT ANSWERS | 2026/2027
ECHELON ECG & CARDIAC MONITORING
1. Stimulation of the sympathetic nerve fibers to the heart produces
which effect on heart rate?
A. Heart rate decreases
B. Heart rate increases
C. Heart rate is unchanged
D. Heart rate becomes irregular only
ANSWER : B. Heart rate increases
Sympathetic stimulation releases norepinephrine, which speeds SA node
firing and AV conduction (positive chronotropy).
Page 1 of 52
, Echelon ECG & Cardiac Monitoring
2. Which heart valves are classified as atrioventricular valves?
A. Aortic and pulmonic
B. Mitral and tricuspid
C. Tricuspid and pulmonic
D. Mitral and aortic
ANSWER : B. Mitral and tricuspid
The tricuspid (right) and mitral (left) valves sit between the atria and
ventricles.
3. Preload is most directly determined by:
A. The force of ventricular contraction
B. The resistance the left ventricle pumps against
C. The heart rate
D. The volume of blood returning to the ventricles at end-diastole
ANSWER : D. The volume of blood returning to the ventricles at end-
diastole
Preload is the stretch on ventricular fibers at end-diastole, governed
largely by venous return.
4. Afterload refers to:
A. The degree of myocardial fiber stretch
B. The amount of blood ejected per beat
C. The resistance the ventricle must overcome to eject blood
D. The volume of blood in the atria
ANSWER : C. The resistance the ventricle must overcome to eject
blood
Afterload is the pressure or resistance against which the ventricle pumps,
mainly systemic vascular resistance for the left ventricle.
5. Which coronary artery most commonly supplies the SA and AV
nodes?
A. Left circumflex artery
B. Left anterior descending artery
C. Right coronary artery
D. Left main coronary artery
ANSWER : C. Right coronary artery
In most people the RCA supplies both nodes, which is why inferior MIs
often cause bradycardia and AV block.
Page 2 of 52
, Echelon ECG & Cardiac Monitoring
6. The left anterior descending artery primarily supplies the:
A. Anterior wall of the left ventricle and anterior septum
B. Inferior wall of the left ventricle
C. Right ventricle
D. Posterior wall of the left atrium
ANSWER : A. Anterior wall of the left ventricle and anterior septum
The LAD perfuses the anterior LV and much of the septum; occlusion
produces changes in V1–V4.
7. The coronary arteries fill primarily during:
A. Ventricular systole
B. Ventricular diastole
C. Atrial systole only
D. Isovolumetric contraction
ANSWER : B. Ventricular diastole
During systole the contracting myocardium compresses the coronary
vessels, so most perfusion occurs in diastole.
8. Starling's law of the heart states that:
A. Greater myocardial stretch produces a stronger contraction, up to a
limit
B. Heart rate rises in response to low blood pressure
C. Afterload determines stroke volume exclusively
D. Stroke volume falls as preload rises
ANSWER : A. Greater myocardial stretch produces a stronger
contraction, up to a limit
Within physiologic limits, increased end-diastolic stretch increases the
force of contraction.
9. The property of cardiac cells to generate an impulse spontaneously is
called:
A. Excitability
B. Conductivity
C. Contractility
D. Automaticity
ANSWER : D. Automaticity
Automaticity allows pacemaker cells to depolarize without external
stimulation.
Page 3 of 52
, Echelon ECG & Cardiac Monitoring
10. The ability of cardiac cells to respond to a stimulus is called:
A. Automaticity
B. Conductivity
C. Excitability
D. Refractoriness
ANSWER : C. Excitability
Excitability (irritability) is the capacity of a cell to respond to an electrical
stimulus.
11. Depolarization of ventricular myocardial cells is triggered mainly
by the rapid influx of:
A. Magnesium
B. Potassium
C. Sodium
D. Chloride
ANSWER : C. Sodium
Phase 0 of the ventricular action potential is caused by fast sodium
channel opening.
12. The plateau phase (phase 2) of the ventricular action potential is
maintained largely by:
A. Sodium-potassium pump failure
B. Slow inward calcium current
C. Rapid sodium influx
D. Chloride efflux
ANSWER : B. Slow inward calcium current
Calcium entry balances potassium exit, prolonging the plateau and
supporting contraction.
13. The relative refractory period corresponds to which part of the
ECG?
A. The ST segment beginning
B. The downslope of the T wave
C. The PR segment
D. The P wave
ANSWER : B. The downslope of the T wave
A strong stimulus during the downslope of the T wave may depolarize
cells, which is the basis for R-on-T phenomenon.
Page 4 of 52
