#1
What does the P wave represent in an ECG?
Atrial depolarization
ExplanationInitial electrical impulse causing atrial contraction.
#2
Which lead is often used as the standard lead in ECG interpretation?
Lead I
ExplanationElectrode placed on the right arm, with the left arm being the reference electrode.
#3
What does the T wave represent in an ECG?
Ventricular repolarization
ExplanationRecovery of ventricular muscle cells, preparing for the next contraction.
#4
Which ECG lead is used to primarily evaluate the lateral wall of the heart?
Lead V6
ExplanationElectrode placement to view the left lateral side of the heart.
#5
Which ECG lead is commonly used to evaluate the septal wall of the heart?
Lead V1
ExplanationElectrode placement to view the septal area of the heart.
#6
Which lead on an ECG is positioned at the 4th intercostal space, right sternal border?
Lead V1
ExplanationElectrode placement to view the right side of the heart.
#7
What does the QRS complex represent in an ECG?
Ventricular depolarization
ExplanationSpread of electrical activity through the ventricles, leading to their contraction.
#8
Which of the following conditions is associated with a prolonged QT interval on an ECG?
Hyperkalemia
ExplanationIncreased potassium levels affecting cardiac repolarization.
#9
Which of the following arrhythmias is characterized by an irregularly irregular rhythm on an ECG?
Atrial fibrillation
ExplanationChaotic electrical signals in the atria, leading to irregular heartbeat.
#10
What is the normal duration range for the PR interval on an ECG?
0.04-0.10 seconds
ExplanationTime taken for electrical impulse to travel from the atria to the ventricles.
#11
Which electrolyte imbalance is commonly associated with a prolonged QT interval on an ECG?
Hypokalemia
ExplanationDecreased potassium levels affecting cardiac repolarization.
#12
What is the typical heart rate range for sinus rhythm on an ECG?
60-100 beats per minute
ExplanationNormal heart rhythm originating from the sinoatrial node.
#13
What does the term 'ST segment elevation' typically indicate on an ECG?
Myocardial infarction
ExplanationSignificant myocardial damage, often indicative of a heart attack.
#14
Which lead placement is commonly used to assess for inferior myocardial infarction?
Lead III
ExplanationElectrode placement to view the inferior wall of the heart.
#15
What is the most common cause of tall, peaked T waves on an ECG?
Hyperkalemia
ExplanationPotassium imbalance affecting ventricular repolarization.
#16
Which segment of the ECG represents the time between ventricular depolarization and repolarization?
ST segment
ExplanationPeriod of time when ventricles are electrically active but not contracting.
#17
In which leads would you primarily observe changes indicating anterior myocardial infarction?
Lead V3, V4
ExplanationElectrode placement to view the anterior wall of the heart.
#18
Which part of the ECG represents ventricular depolarization?
QRS complex
ExplanationPeriod when ventricles are electrically stimulated to contract.