Question 1
Normal QRS intervals should be
◦ less than 0.12 seconds wide.
◦ less than 0.20 seconds wide.
◦ between 0.12 and 0.20 seconds wide.
◦ alternately narrow and wide.
Question 2
The normal rhythm originating in the sinus node should have a heart rate that is
◦ greater than 100.
◦ between 60 and 100.
◦ between 40 and 60.
◦ less than 60.