| Flap 1 | Flap 2 |
| P wave | atrial DEpolarization |
| PR interval | time required for impulse to travel from atria through conduction system to Purkinje fibers |
| QRS wave | ventricular DEpolarization |
| ST segment | beginning of ventricular REpolarization |
| T wave | ventricular REpolarization |
| QT interval | time for electrical systole |
| Heart Rate | # of intervals between QRS complexes in a 6-second strip multiplied by 10 |
| Ventricular arrhythmias | originate from an ectopic focus in the ventricles (outside normal conduction system) |
| Ventricular fibrillation | pulseless, emergency situation requiring EMT: CPR, defibrillation, medications |
| Premature ventricular contractions (PVCs) | NO P wave, bizarre & wide QRS that is premature, followed by a long compensatory pulse |
| Serious PVCs | >6 per minute, paired or in sequential runs, multifocal, very early PVC (R on T Phenomena) |
| Ventricular tachycardia | 3 or more PVCs occuring sequentially; very rapid rate (150-200 bpm) |
| Ventricular tachycardia | wide, bizarre QRS waves, NO P waves, seriously compromised cardiac output |
| Ventricular fibrillation | chaotic activity of ventricle originating from multiple foci; unable to determine rate |
| Ventricular fibrillation | bizarre, erratic activity without QRS complex |
| Ventricular fibrillation | No effective cardiac output; clinical death within 4-6 mins |
| Atrial arrhythmias (supraventricular) | Rapid & repetitive firing of 1 or more ectopic foci in the atria |
| Atrial arrhythmias (supraventricular) | P waves abnormal (variable in shape) or not identifiable (atrial fibrillation) |
| Atrial tachycardia | 140-250 bpm |
| Atrial flutter | 250-350 bpm |
| Atrial fibrillation | >300 bpm |
| Atrioventricular blocks | ab(N) delays or failure to conduct through (N) conductiong system |
| If ventricular rate is slowed, | Cardiac output is decreased |
| 3rd degree AV block | life threatening, requires meds (ATROPHINE), pacemaker |
| ST depression | impaired coronary perfusion (ischemia or injury) |
| MI central zone of infarction | Ab(N) Q waves |
| MI zone of injury | ST elevation |
| MI zone of ischemia | T wave inversion |
| Hyperkalemia | wide QRS, flat P wave, peaked T wave |
| Hypokalemia | flat T wave (or inverted), produces U wave |
| Hypercalcemia | wide QRS, short QT interval |
| Hypocalcemia | prolonged QT interval |
| Hypothermia | ST segment elevation; slow rhythm |
| Digitalis | ST segment depression, flattened T wave (or inverted), shortened QT |
| Quinidine | long QT, T flat/inverted, QRS long |
| BetaBlockers (Propranolol/Inderal) | decreased heart rate, blunts HR response to exercise |
| Nitrates (nitoglycerin) | Inc HR |
| Antiarrhythmic agents | may prolong QRS & QT intervals |
