Understanding ECG Waveforms and Rhythm

What is the normal duration of a P wave on an ECG?

• 0.04 to 0.08 seconds

• 0.08 to 0.12 seconds

• 0.12 to 0.20 seconds

• 0.20 to 0.24 seconds

Which part of the ECG represents ventricular depolarization?

• P wave

• QRS complex

• T wave

• U wave

How many small boxes on an ECG strip represent 1 second?

• 5

• 10

• 20

• 25

What is the normal duration of the QRS complex?

• 0.04 to 0.08 seconds

• 0.08 to 0.12 seconds

• 0.12 to 0.20 seconds

• 0.20 to 0.24 seconds

How do you calculate heart rate using the large box method on an ECG?

• 1500 divided by the number of large boxes between R waves

• 300 divided by the number of large boxes between R waves

• 1500 divided by the number of small boxes between R waves

• 300 divided by the number of small boxes between R waves

Which lead is placed on the right arm in a standard 12-lead ECG?

• Lead I

• Lead II

• Lead III

• Lead aVR

What is the characteristic shape of a normal P wave?

• Upright and rounded

• Inverted and sharp

• Flat and wide

• Biphasic

In a normal sinus rhythm, where does the electrical impulse originate?

• Atrioventricular node

• Sinoatrial node

• Bundle of His

• Purkinje fibers

What is the standard paper speed for an ECG recording?

• 10 mm/s

• 25 mm/s

• 50 mm/s

• 100 mm/s

Which wave on the ECG represents atrial depolarization?

• P wave

• QRS complex

• T wave

• U wave