ECG or Electrocardiograph is a test that is used to assess the muscular and electrical functionalities of the heart. It is a painless test which can be conducted in a few minutes and results can also be read instantly. An electrocardiograph is basically a graph of voltage plotted against time of electrical activity of the heart.
The electrical activity of the heart - The electrical system is the power source that makes the working of the heart possible in a nutshell. The electrical impulses trigger the heartbeat that travels down a pathway through the heart. These pathways are conduction pathways and they are responsible for causing ventricles of the heart to contract and pump out blood. The human heart has a natural pacemaker which produces these electrical impulses all by itself. These electrical impulses generate an electrical current that spreads over our body. An electrocardiogram measures these currents in the form of wave graphs on a paper.
The electrodes of the electrocardiogram are placed on the skin to note the normal working conditions of the heart. These electrodes detect the electrical impulses occurring during each heartbeat. The impulses are picked up from the changes in an electrical path on the skin. These changes arise from the heart muscles and the electrophysiologic patterns of the depolarizing.
Let’s have a look at some solved Multiple-choice questions on ECG
1. Who developed an Electrocardiogram?
2.In case of a normal Heartbeat, Depolarization stimulus arises in which of the following?
Sinoatrial Node (SA node)
Atrioventricular Node (AV node)
3. What does the P wave represent?
Depolarization of the atria
Depolarization of the ventricles
Represents the repolarization of the ventricles
Depolarization of the atria and ventricles
4. Which of these cannot be detected by an Electrocardiogram?
The rate and rhythm of Heartbeats
The size and position of the Heart chambers
The function of implanted Pacemakers
Presence of asymptomatic blockages in the atria of the Heart
5. Which of the following indicates Ventricular Muscle Depolarization?
6. What does the T wave represent in an ECG?
7. What does the Depolarization of Ventricles initiate?
8. Counting the number of QRS complexes, which of the following can be interpreted?
Rate of heart beat
Rate of breathing
9. What do Depolarization and Repolarization initiate in different chambers of the Heart?
Contraction and relaxation
Relaxation and contraction
Thickening and thinning
Contraction and thickening
10. Which of the following waves of ECG represent Repolarization?
11. In a single circulation the Heart Pumps?
Only blood nutrients
12. The Depolarization Stimulus for the normal Heartbeat originates in the
Atrioventricular (AV) nodal
Sinoatrial (SA) node
13. A shortened PR interval, slurring (called a delta wave) of the initial QRS deflection, and prolonged QRS duration are characteristics of
Wolff-Parkinson-White (WPW) syndrome
B. Atrial tachycardia
C. Left bundle branch block
D. Myocardial ischemia
14. The classic ECG changes in Myocardial Infarction (MI) are
Development of an abnormal Q wave
All of the above
15. ECG depicts the Depolarisation and Repolarisation processes during the Cardiac Cycle. In the ECG of a normal healthy individual one of the following waves is not represented, which one is that?
Depolarization of atria
Repolarization of atria
Depolarization of ventricles
Repolarization of ventricles
16. Which of the following correctly explains a phase/ event in cardiac cycle in a standard Electrocardiogram?
QRS complex indicates atrial contraction.
QRS complex indicates ventricular contraction.
Time between S and T represents atrial systole.
P-wave indicates beginning of ventricular contraction.
17. In a normal individual, the heart rate can be determined by the ___________ in an ECG
Interval between two QRS complexes
Number of P waves
Interval between the P and T waves
Number of T waves
18. This is the classic ECG change in MI (Myocardial Infarction)
Development of an abnormal Q wave
All of these
19. In which of these conditions can widened QRS and Tall-tented T waves be observed
20. A particular ECG change observed in Hypokalemia is
ST segment elevation
U wave, which is a position deflection after the T wave
Tall peaked T waves
Widening of the QRS complex and increased amplitude
21. ECG identified by the PR interval tends to become longer with every succeeding ECG complex until there is a P wave not followed by a QRS is observed in
Third-Degree Atrioventricular Block
Second-Degree Atrioventricular Block, Type II
Second-Degree Atrioventricular Block, Type I
First-Degree Atrioventricular Block, Type II