Myocardium vs pericardium?●Myocardium - middle layer of heart wall consisting of cardiac muscle fibers that enable contractions of the heart●Pericardium - Outer membrane that encloses the heart consisting of an external fibrous layer and an inner double layer of serous membraneDepolarization vs repolarization (what each is?)●Depolarization - Contraction●Repolarization - relaxationElectrical activity of the heart, What cells are activated?●Pacemaker cellsElectrical activity of the heart is influenced by what?●Electrolytes?What is the primary pacemaker, gatekeeper?●Primary - SA node●Gatekeeper - AV nodeWhat is hypokalemia, hyperkalemia, hyponatremia, hypernatremia? (definition)●If one increases or decreases what could it cause (signs/symptoms and how it changes ekg)○Hypokalemia: Flat T waves/Depressed P waves/U-waves■Signs: Supraventricular arrhythmias, muscle weakness, Cardiac arrest○Hyperkalemia: Tall peaked T-waves/Wide QRS/Prolonged PR int./Flat P wave■Signs: Ventricular arrhythmias, Cardiac Arrest○Hyponatremia: No EKG changes■Causes: Tachycardia, Orthostatic Hypertension, weakness○Hypernatremia: No EKG changes■Tremors, irritability, coma, seizures,What can cause hyponatremia and what could hyponatremia cause as it relates to the heart?●Caused by:○Excessive fluid intake○Sodium depletion without replacement○Diuretic therapy●Heart arrhythmias??Intrinsic rate for SA node and AV node/purkinje fibers, bundle of hiss.●SA Node: 60-100 bpm●AV node: 40-60 bpm●Bundle of His: 40-60 bpm●Purkinje System: 20-40 bpm
Most common lead placement?●III Lead placement, view IIWhy would you look at view 1 and 3?●To locate a specific area/problem of the heartWhat does the P wave and QRS complex represent?