L11: ECG

Question 1

electrocardiogram (ECG ) does not give direct information about contractile function of the heart , what technique would be best to attain that information ?

Answer 1

echocardiography

Question 2

What does the P wave represent on an ECG ?

Answer 2

atrial depolarization (0.08-0.12 sec.)

Question 3

what does the QRS complex represent on an ECG ?

Answer 3

ventricular depolarization

Question 4

what does the T wave represent on an ECG ?

Answer 4

ventricular repolarization

Question 5

why is the atrial depolarization not visible on an ECG ?

Answer 5

because it is masked by the QRS complex / ventricular depolarization

Question 6

what is the p wave followed by ?

Answer 6

atrial contraction

Question 7

what is the QRS complex followed by ?

Answer 7

ventricular contraction (systole )

Question 8

what is the P-R interval ?

Answer 8

from start of p wave to start of QRS complex . it represents the time it takes for action potential to reach ventricles

Question 9

what is the Q-T interval ?

Answer 9

it is measured from the start of QRS complex to the END of T wave . it indicates the duration of ventricular systole

Question 10

what is the S-T segment ?

Answer 10

it is measured from the end of QRS complex to the start of T wave ( elevated in case of myocardial infraction)