Q: Which equation would you use to calculate heart rate from an ECG if you know the time interval between two consecutive R waves is $$0.8$$ seconds?

$$\text{Heart Rate} = \frac{60}{\text{Interval (s)}}$$

Question 1

Which part of the ECG corresponds to the depolarization of the ventricles?

Accepted Answer

QRS complex

Question 2

A patient’s ECG shows a heart rate of 50 bpm. Which term best describes this condition?

Accepted Answer

Bradycardia

Question 3

During which phase of the ECG do the atria depolarize?

Accepted Answer

P wave

Question 4

If the PR interval is abnormally prolonged on an ECG, which part of the heart’s conduction system is most likely affected?

Accepted Answer

AV bundle

Question 5

Which of the following best describes the physiological events occurring between the beginning of the QRS complex and the end of the T wave?

Accepted Answer

Ventricular depolarization and repolarization

Question 6

A patient’s ECG shows rapid, uncoordinated electrical activity with no identifiable P waves, QRS complexes, or T waves. Which condition does this most likely indicate?

Accepted Answer

Ventricular fibrillation

Question 7

Which equation would you use to calculate heart rate from an ECG if you know the time interval between two consecutive R waves is $$0.8$$ seconds?

Accepted Answer

$$	ext{Heart Rate} = \frac{60}{	ext{Interval (s)}}$$

Question 8

A varsity athlete’s ECG shows a resting heart rate of 55 bpm, but the doctor is not concerned. Which term best describes this finding?

Accepted Answer

Bradycardia

Question 9

Which of the following is true regarding the T wave on an ECG?

Accepted Answer

It represents ventricular repolarization

Question 10

A patient’s ECG shows a heart rate of 120 bpm. Which term best describes this condition?

Accepted Answer

Tachycardia

Question 11

Which of the following best explains why ventricular fibrillation is immediately life-threatening?

Accepted Answer

It prevents effective pumping of blood to the body

Question 12

If a patient’s ECG shows a disrupted signal with irregular spacing between QRS complexes, which pathology is most likely present?

Accepted Answer

Heart block

Question 13

Which of the following best describes the function of the PR interval on an ECG?

Accepted Answer

It measures the time for atrial depolarization and AV node delay

Question 14

A patient’s ECG shows a normal P wave, but the QRS complex is missing. Which part of the conduction system is most likely failing?

Accepted Answer

AV bundle

Question 15

Which of the following is the correct sequence of electrical events in the heart as seen on a normal ECG?

Accepted Answer

P wave, QRS complex, T wave

Question 16

If the time between two consecutive R waves on an ECG is $$0.5$$ seconds, what is the heart rate?

Accepted Answer

$$120$$ bpm

Question 17

Which of the following best describes the QRS complex on an ECG?

Accepted Answer

Ventricular depolarization

Question 18

A patient’s ECG shows a heart rate of 45 bpm and regular rhythm. Which of the following is the most likely diagnosis?

Accepted Answer

Bradycardia

Question 19

Which of the following is NOT a possible cause of an abnormal ECG?

Accepted Answer

Proper conduction through the AV bundle

Question 20

Which of the following best describes the clinical significance of the ST segment on an ECG?

Accepted Answer

It represents the plateau phase of ventricular contraction

Electrocardiogram (ECG): Principles and Pathologies

Guida di studio - Domande di pratica

Study guide - Flashcard