CRAT Study Guide
Normal PRI interval - answer0.12-0.20
Normal QRS interval - answer0.11 or less
What does the P wave represent? - answerAtrial depolarization
What does the QRS complex represent? - answerAtrial repolarization and ventricular
depolarization
Q wave indicates what? - answerDead myocardial tissue. Always a negative deflection
What is the natural pacemaker of the heart? - answerSA node
3 types of pacemakers - answer1) single (either RA or RV)
2) dual chamber (RA and LV)
3) bi-ventricular (RV and LV --> Congestive Heart Failure)
Which HB would you NOT need a pacemaker for? - answerFirst-degree AV block
(prolonged PRI >0.20 seconds)
Define intrinsic beats - answerThe patient's own heart beat
What is sensing? - answerThe ability for the heart to sense and respond to the electrical
activity of the heart
What is capture? - answerThe pacemaker sends a stimulus to the heart which causes
the heart to depolarize
Failure to sense - answerLack of pacemaker spikes where they should have been.
Battery can be dead.
Failure to capture (loss of capture) - answerNo P or QRS after the pacemaker spike
Undersensing - answerPacemaker spikes in areas where they should not be (i.e. in the
T wave, an ST segment, or on top of another QRS)
Normal PRI interval - answer0.12-0.20
Normal QRS interval - answer0.11 or less
What does the P wave represent? - answerAtrial depolarization
What does the QRS complex represent? - answerAtrial repolarization and ventricular
depolarization
Q wave indicates what? - answerDead myocardial tissue. Always a negative deflection
What is the natural pacemaker of the heart? - answerSA node
3 types of pacemakers - answer1) single (either RA or RV)
2) dual chamber (RA and LV)
3) bi-ventricular (RV and LV --> Congestive Heart Failure)
Which HB would you NOT need a pacemaker for? - answerFirst-degree AV block
(prolonged PRI >0.20 seconds)
Define intrinsic beats - answerThe patient's own heart beat
What is sensing? - answerThe ability for the heart to sense and respond to the electrical
activity of the heart
What is capture? - answerThe pacemaker sends a stimulus to the heart which causes
the heart to depolarize
Failure to sense - answerLack of pacemaker spikes where they should have been.
Battery can be dead.
Failure to capture (loss of capture) - answerNo P or QRS after the pacemaker spike
Undersensing - answerPacemaker spikes in areas where they should not be (i.e. in the
T wave, an ST segment, or on top of another QRS)
