1. On a normal ECG, awave for atrial repolarization is not recorded. Why?
a. No repolarizationof the atria occurs normally.
b. It occurs at thesame time as ventricular depolarization and is masked by the QRScomplex.
c. It is too small tobe picked up by the recording electrodes.
2. If the duration ofone cardiac cycle is 0.71 seconds, what is the heart rate?
(68.2 BPM-92.5 BPM-78 BPM-84.5 BPM)
3. Pick the answer which best explains the lag time between thestart of QRS and the start of the thumb pulse.
a. It is the time theblood takes to reach the thumb.
b. It is the time ittakes for the ventricles to empty and the blood to reach thethumb.
c. It is the timewhich includes the duration of QRS, the contraction of theventricles and the time it takes the blood to reach the thumb.