CRAT Study

CRAT Study Normal PRI interval - ANSWER 0.12-0.20 Normal QRS interval - ANSWER 0.11 or less What does the P wave represent? - ANSWER Atrial depolarization What does the QRS complex represent? - ANSWER Atrial repolarization and ventricular depolarization Q wave indicates what? - ANSWER Dead myocardial tissue. Always a negative deflection What is the natural pacemaker of the heart? - ANSWER SA node 3 types of pacemakers - ANSWER 1) 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? - ANSWER First-degree AV block (prolonged PRI 0.20 seconds) Define intrinsic beats - ANSWER The patient's own heart beat What is sensing? - ANSWER The ability for the heart to sense and respond to the electrical activity of the heart What is capture? - ANSWER The pacemaker sends a stimulus to the heart which causes the heart to depolarize Failure to sense - ANSWER Lack of pacemaker spikes where they should have been. Battery can be dead. Failure to capture (loss of capture) - ANSWER No P or QRS after the pacemaker spike Undersensing - ANSWER Pacemaker spikes in areas where they should not be (i.e. in the T wave, an ST segment, or on top of another QRS