#1
In lead II of a standard ECG, the positive electrode is placed on which part of the body?
Left arm
ExplanationPositive electrode is on the left arm, negative on the right leg.
#2
In lead aVR, the positive electrode is placed on which part of the body?
Right arm
ExplanationPositive electrode is on the right arm, negative on the left arm and left leg.
#3
What is the primary purpose of the ECG electrode gel?
Enhance electrical conductivity
ExplanationImproves the conduction of electrical signals between the skin and electrodes.
#4
In lead III of a standard ECG, the positive electrode is placed on which part of the body?
Left leg
ExplanationPositive electrode is on the left leg, negative on the right arm and left arm.
#5
Which limb leads are included in the standard 12-lead ECG?
All of the above
ExplanationInclude leads I, II, III, aVR, aVL, and aVF.
#6
What is the significance of the P wave in an ECG?
Represents atrial depolarization
ExplanationIndicates the electrical activity of atrial contraction.
#7
Which precordial lead is commonly used to assess the anterior wall of the heart?
V4
ExplanationPositioned to capture electrical activity from the front of the heart.
#8
Which lead is used to evaluate the lateral wall of the heart in a standard 12-lead ECG?
aVL
ExplanationProvides a lateral view of the heart's electrical activity.
#9
Which lead provides a view of the inferior wall of the heart in a standard 12-lead ECG?
II
ExplanationCaptures electrical activity from the bottom of the heart.
#10
Which lead is commonly used to assess the lateral wall of the left ventricle?
aVL
ExplanationProvides a lateral view of the left ventricle's electrical activity.
#11
What does the QRS complex represent in an ECG tracing?
Ventricular depolarization
ExplanationDepicts electrical activity during ventricular contraction.
#12
What is the normal duration of the PR interval in an ECG?
0.12 - 0.20 seconds
ExplanationTime for atrial depolarization to ventricular depolarization.
#13
In an ECG, what does the term 'ST segment' represent?
Isoelectric period between ventricular depolarization and repolarization
ExplanationRepresents the resting period after ventricular contraction.
#14
What does the T wave represent in an ECG tracing?
Ventricular repolarization
ExplanationIndicates the recovery phase of the ventricles.
#15
What is the primary function of the AV node in the cardiac conduction system?
Coordinate atrial and ventricular contractions
ExplanationEnsures synchronized contraction between atria and ventricles.
#16
What does the term 'QT interval' represent in an ECG?
Time from the start of the QRS complex to the end of the T wave
ExplanationDuration of ventricular depolarization and repolarization.