Normal Sinus Rhythm - MissingLink正常窦性心律missinglink.pptVIP

EKG Rhythm Interpretation ECG Rhythm Interpretation Module IIINormal Sinus Rhythm Course Objectives To recognize the normal rhythm of the heart - “Normal Sinus Rhythm.” To recognize the 13 most common rhythm disturbances. To recognize an acute myocardial infarction on a 12-lead ECG. Learning Modules ECG Basics How to Analyze a Rhythm Normal Sinus Rhythm Heart Arrhythmias Diagnosing a Myocardial Infarction Advanced 12-Lead Interpretation Normal Sinus Rhythm (NSR) Etiology: the electrical impulse is formed in the SA node and conducted normally. This is the normal rhythm of the heart; other rhythms that do not conduct via the typical pathway are called arrhythmias. NSR Parameters Rate 60 - 100 bpm Regularity regular P waves normal PR interval 0.12 - 0.20 s QRS duration 0.04 - 0.12 s Any deviation from above is sinus tachycardia, sinus bradycardia or an arrhythmia Arrhythmia Formation Arrhythmias can arise from problems in the: Sinus node Atrial cells AV junction Ventricular cells SA Node Problems The SA Node can: fire too slow fire too fast Sinus Bradycardia Sinus Tachycardia Atrial Cell Problems Atrial cells can: fire occasionally from a focus fire continuously due to a looping re-entrant circuit Premature Atrial Contractions (PACs) Atrial Flutter Teaching Moment A re-entrant pathway occurs when an impulse loops and results in self-perpetuating impulse formation. Atrial Cell Problems Teaching Moment AV Junctional Problems The AV junction can: fire continuously due to a looping re-entrant circuit block impulses coming from the SA Node Paroxysmal Supraventricular Tachycardia AV Junctional Blocks Ventricular Cell Problems Ventricular cells can: fire occasionally from 1 or more foci fire continuously from multiple foci fire continuously due to a looping re-entrant circuit Premature Ventricular Contractions (PVCs) Ventricular Fibrillation Ventricular Tachycardia End of Module IIINormal Sinus Rhythm Proceed to Module III Practice