ECG Basics

What is the main function of the cardiac conduction system?

• Digest food

• Control body temperature

• Regulate blood pressure

• Regulate the heart's rhythm and coordinate the contraction of heart chambers.

Which part of the heart is known as the pacemaker?

• sinoatrial (SA) node

• ventricles node

• heartstrings

• atrioventricular (AV) node

What does the P wave represent in an ECG waveform?

• Atrial depolarization

• Ventricular depolarization

• Atrial repolarization

• Ventricular repolarization

What does the QRS complex represent in an ECG waveform?

• AV node delay

• Atrial repolarization

• Ventricular depolarization

• SA node firing

Which lead is commonly used to monitor the heart's electrical activity?

• Lead III

• Lead IV

• Lead V

• Lead II

Where is the positive electrode placed in Lead I?

• Left leg (LL)

• Right leg (RL)

• Right arm (RA)

• Left arm (LA)

What does a prolonged PR interval indicate in an ECG?

• Delayed conduction through the AV node

• Normal heart conduction

• Increased heart rate

• Low blood pressure

How many leads are used in a standard 12-lead ECG?

• 10 leads

• 6 leads

• 8 leads

• 14 leads

What is the normal duration of the QT interval?

• 0.20 to 0.30 seconds

• 1.00 to 1.20 seconds

• 0.36 to 0.44 seconds

• 0.50 to 0.60 seconds

What does ST segment elevation indicate in an ECG?

• Atrial fibrillation

• Myocardial infarction

• Pulmonary embolism

• Hypertension