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Cardiac Terms
Medical-Surgical Nursing Fifth Edition
| Question | Answer |
|---|---|
| Automaticity | ability of the pacemaker cell to spontaneously initiate an electrical |
| Conductivity | the ablility of a cell to transmit an impulse from cell to cell |
| Contractility | the natural ability of myocardial fibers to shorten in response to an electrical stimulus |
| Depolarization | the change in a membrane potential from a negative to a positive state |
| Excitability | myocardial cells that contract in response to an impulse |
| Myocardial working cells | the ability of a cardiac working cell to respond to an electrical impulse |
| Pacemaker cells | cells that spontaneously generate an electrical impulse |
| Polarized | the condition of a cell in the resting state with positive and negative ions aligned on either side of the cell membrane |
| Refractory period | the stage in which a cell is resistant to stimulation |
| Sarcomere | portion of myocardial cell where calcium ions act on actin and myosin, causing myocardial contraction |
| P wave | represents atrial depolarization |
| PR interval | represents time need for sinus impulse to reach the AV node |
| QRS complex | represents ventricular depolarization |
| QT interval | total time for ventricular depolarization and repolarization |
| ST segment | represents the beginning of ventricular repolarization |
| Primary pacemaker of the heart | sinus (SA) node |
| Atrial Flutter | the saw-tooth or picket fence appearance of the P wave on an ECG |
| Cardiac dysrhythmia | is a disturbance or irregularity in the electrical system of the heart |