Advanced – Dysrhythmias Exams Questions & Answers 100% Correct!!

Excitability - ANSWERthe ability of non-pacemaker heart cells to respond to an electrical impulse that begins in pacemaker cells. Depolarization - ANSWERoccurs when the normally negatively charged cells within the heart muscle develop a positive charge. Conductivity - ANSWERthe ability to send an electrical stimulus from cell membrane to cell membrane. As a result, excitable cells depolarize in rapid succession from cell to cell until all cells have depolarized. Ex: the wave of depolarization causes the deflections in the ECG waveforms that are recognized as the P wave and QRS complex. Contractility - ANSWERthe ability of atrial and ventricular muscle cells to shorten their fiber length in response to electrical stimulation, causing sufficient pressure to push blood forward through the heart. In other words, this is the mechanical activity of the heart. AV Node - ANSWERwhere impulses slow down or are delayed before proceeding to the ventricles. This delay is reflected in the PR segment on the ECG. This slow conduction provides a short delay, allowing the atria to contract and the ventricles to fill. SA Node - ANSWERthe heart's primary pacemaker. It can spontaneously and rhythmically generate electrical impulses at a rate of 60-100 beats per min and therefore has the greatest degree of automaticity. Purkinje Cells - ANSWERcomposed of the bundle of HIS, bundle branches, and these fibers. Responsible for the rapid conduction of electrical impulses throughout the ventricles, leading to ventricular depolarization and the subsequent ventricular muscle contraction. Semi-Reclined - ANSWERWhile obtaining a 12-lead ECG, remind the patient be as as still as possible in a ________________________ position, breathing normally. Clea, Dry, Moist - ANSWERFor continous ECG monitoring, be sure to __________________ skin and clip hairs/shave. Ensure that the electrode placement is _____________ and the gel on each electrode is ______________ and fresh. P Wave - ANSWERa deflection on an ECG representing atrial depolarization. When the electrical impulse is consistently generated form the SA node, this wave has a consistent shape in a given lead. If an impulse is then generated from a different (ectopic) focus, such as atrial tissue, the shape of this wave changes in the lead, indicating that an ectopic focus has fired. PR Segment - ANSWERthe isoelectric line from the end of the P wave to the beginning of the QRS complex, when the electrical impulse is traveling through the AV node, where it is delayed.