ECG

Question 1

What does an elevated ST segment on an ECG indicate?
A. Atrial fibrillation
B. Ventricular tachycardia
C. Myocardial infarction
D. Hypertension

Answer 1

C. Myocardial infarction

ST-segment elevation suggests acute myocardial infarction (heart attack) due to lack of oxygen in heart tissue, leading to cell death.

Question 2

What does the P wave on an ECG represent?
A. Atrial depolarization
B. Ventricular depolarization
C. Ventricular repolarization
D. Atrial repolarisation

Answer 2

A. Atrial depolarization

The P wave represents atrial depolarisation, meaning the atria contract to push blood into the ventricles. Ventricular depolarization is represented by the QRS complex.

Question 3

What does the QRS complex on an electrocardiogram (ECG) represent?
A. Atrial depolarization
B. Ventricular depolarization
C. Ventricular repolarization
D. Atrial repolarisation

Answer 3

B. Ventricular depolarisation

The QRS complex represents the electrical activity that leads to ventricular contraction. The P wave corresponds to atrial depolarization, and the T wave represents ventricular repolarization. A prolonged or abnormal QRS complex may indicate ventricular dysfunction, heart block, or myocardial infarction.