Cardiac Rhythm Assessment ECG
Interpretation Exam Questions With
Complete Solutions
What is the SA node - ANSWER - It is the heart's pacemaker cell and forms the sinus rhythm of the heart.
It is automatic
What are unique characteristics of the myocytes of the heart? - ANSWER - They can automatically send
electrical current without stimulation from the NS. Conductivity transmitts impulses rapidly to other
cells--> heart contracts as a unit
How do myocytes participate in depolarization and repolarization? - ANSWER - they do it by having a
negative IC at rest and then it becoming positive at it depolarizes and cells contract. Repolariztoin is
phase when it goes back to becoming negative.
What is dysrhythmia? - ANSWER - it is a disturbance of transmission or discharge of electrical impulse in
the heart (so it can be conductance or automaticity)
How do we increase stroke volume? - ANSWER - decrease after load, increased contractility, and
increased preload
What is the time scale on an ECG? - ANSWER - each small box is .04 seconds and each big section is .2
seconds
Why is the QRS complex is so large on an ECG? - ANSWER - because of location of lead II which is going
from R shoulder to L LE and so L ventricle is larger so going towards that will have a positive deflection
on lead II
What is the difference between segment and interval? - ANSWER - Segment is only baseline while
interval includes waves and intervals.
Interpretation Exam Questions With
Complete Solutions
What is the SA node - ANSWER - It is the heart's pacemaker cell and forms the sinus rhythm of the heart.
It is automatic
What are unique characteristics of the myocytes of the heart? - ANSWER - They can automatically send
electrical current without stimulation from the NS. Conductivity transmitts impulses rapidly to other
cells--> heart contracts as a unit
How do myocytes participate in depolarization and repolarization? - ANSWER - they do it by having a
negative IC at rest and then it becoming positive at it depolarizes and cells contract. Repolariztoin is
phase when it goes back to becoming negative.
What is dysrhythmia? - ANSWER - it is a disturbance of transmission or discharge of electrical impulse in
the heart (so it can be conductance or automaticity)
How do we increase stroke volume? - ANSWER - decrease after load, increased contractility, and
increased preload
What is the time scale on an ECG? - ANSWER - each small box is .04 seconds and each big section is .2
seconds
Why is the QRS complex is so large on an ECG? - ANSWER - because of location of lead II which is going
from R shoulder to L LE and so L ventricle is larger so going towards that will have a positive deflection
on lead II
What is the difference between segment and interval? - ANSWER - Segment is only baseline while
interval includes waves and intervals.
