Normal Sinus Rhythm - UHSM正常窦性心律意义.pptVIP

Segments PR segment measured? ST segment measured? Limb leads Measurements - lead II QRS Axis P wave Axis Chest Leads Progression of R waves throughout the chest leads Transitional Zone Phases of Activation Depolarisation Stages 1 2 3 Typical complexes in the Pre-cordial leads V1 V2 V3 V4 V5 V6 Progression of R waves throughout the chest leads Size of the R wave should increase from V1 to V6. V4 Usually at the Apex (Transitional Zone where the first negative wave appears). R Wave Progression Practical Challenges Sinus Rhythms Sinus Bradycardia Sinus Tachycardia Sinus arrhythmia 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 QT interval not exceed 0.42 seconds. U wave Sinus Bradycardia - Rate 60 b pm Etiology: SA node is depolarizing slower than normal, impulse is conducted normally (i.e. normal PR and QRS interval). Sinus Tachycardia - Rate 100 bpm Etiology: SA node is depolarizing faster than normal, impulse is conducted normally. Remember: sinus tachycardia is a response to physical or psychological stress, not a primary arrhythmia. Sinus arrythmia Rate – variable Etiology: SA node is depolarizing t a variable rate , impulse is conducted normally (i.e. normal PR and QRS interval). Normal Rhythms !!! *Sinus Arrest* Considered a ‘Sinus rhythm’ but is abnormal Rhythm 1 130 bpm Rate? Regularity? regular normal 0.08 s P waves? PR interval? 0.16 s QRS duration? Interpretation? Sinus Tachycardia Rhythm 2 30 bpm Rate? Regularity? regular normal 0.10 s P waves? PR interval? 0.12 s QRS duration? Interpretation? Sinus Bradycardia ECG INTERPRETATION If the normal ECG is known then interpretation of abnormals becomes easier EASY ? References/Bibliography www.RNCEUS.com /thi/arrhythm.html ctmed * 1887 British physiologist Augustus D. Waller of St Marys Medical Scho