IBHRE國際心律失?？脊傥瘑T會英文資料：Electrocardiography_plus_interestingECGs

1、VI. Electrocardiology (8%) VI. Electrocardiography (16 Questions) A. Normal Electrocardiogram, Recognition B. Transesophageal Electrocrdiography C. Recognition of Arrhythmia, ECG Abnormalities D. Recognition of Pacemaker ECG Anatomy of the 12 Lead EKG LIMB LEADS StandardAugmented EKGs are events on

2、a timeline Surface electrograms are a summation of cardiac electrical activity measured outside of the cardiac cell. 1.Amplitude mass, strength, healthy vs-disease tissue 2.Velocity speed of conduction measured by slope (dV/dT) 3.Directionality vector or path of conduction Einthovens Theory: An impu

3、lse traveling toward a positive recording electrode generates a positive deflection. Therefore, an impulse traveling away from a positive recording electrode generates a _deflection qAmplitude mass, strength, healthy vs-disease tissue qVelocity speed of conduction measured by slope (dV/dT) qDirectio

4、nality vector or path of conduction Einthovens Theory: An impulse traveling toward a positive recording electrode generates a positive deflection. Therefore, an impulse traveling away from a positive recording electrode generates a _deflection Negative Relationship of BPM and CL in Milliseconds CL m

5、sec = 60,000/bpm BPM = 60,000/CL (ms) EKG QRS Vector q Normal conduction is right to left, high to low (superior to inferior). ECG GRPAH & RATE CALCULATION EKG Axis / Morphology Figure A EKG Axis / Morphology Figure A Normal EKG Axis Morphology Figure B EKG Axis Morphology Figure B Low to high, abno

6、rmal ECG Rhythm Analysis: Systematic Approach to ECGs qRhythm - Regular or Irregular qHeart Rate slow, normal or fast qP Wave - Normal, Long, Short PR interval qAssociated with QRS - In front or behind qDisorder ECG OF THE HEALTHY HEART 1:1 AV synchrony (one atrial event for each ventricular event)

7、Stable rhythm with repeating patterns Morphologies of beats should be similar from complex to complex Rate should be appropriatenot too fast, not too slow ZONE OF TRANSITION: THE KEY TO THE MECHANISM The onset of tachycardia warm up, abrupt, pause/jump The termination of tachycardia slow down, abrup

8、t Change to an alternate QRS morphology Rate change with morphology change Irregularities in cycle length Ectopic cycles DIFFERENTIAL DIAGNOSIS OF WIDE QRS TACHYCARDIA SVT tachycardia with aberrancy Ventricular tachycardia Pre-excited tachycardia SIGNS OF ARRHYTHMIC ACTIVITY ON AN ECG Abnormally sha

9、ped waves Lack of 1:1 AV synchrony Rapid cardiac activity, even if otherwise stable Very slow cardiac activity, even if otherwise stable Irregular cardiac activity Variability in PR interval “Missing” cardiac events Pauses Premature beats (oddly timed events) REVIEW OF PQRST NOW I KNOW MY EKGS P wav

10、e: the sequential activation (depolarization) of the right and left atria QRS complex: right and left ventricular depolarization (normally the ventricles are activated simultaneously) ST-T wave: ventricular repolarization U wave: origin for this wave is not clear - but probably represents after depo

11、larizations in the ventricles PR interval: time interval from onset of atrial depolarization (P wave) to onset of ventricular depolarization (QRS complex) QRS duration: duration of ventricular muscle depolarization QT interval: duration of ventricular depolarization and repolarization RR interval: d

12、uration of ventricular cardiac cycle (an indicator of ventricular rate) PP interval: duration of atrial cycle (an indicator of atrial rate) ANATOMY OF AN ECG 12 Leads NSR Atrial Tachycardia Atrial Flutter Atrial Fibrillation WPW (AVRT) AVNRT VT Brugada Rule of 300 E. Transesophageal Electrocardiogra

13、phy 1. Electrode placement a. Atrial pacing 1) 7-11 cm above gastroesophageal junction b. Ventricular pacing 1) 2-4 cm above gastroesophageal junction c. Quadripolar electrodes maybe used d. Current levels 1) 25 mA effective 2) Greater than 60 mA causes injury in animals 3) Need esophageal pacemaker

14、 E. Transesophageal Electrocardiography Cont 2. Indications a. Initiate and terminate various supraventricular tachycardias b. Distinguish between different types of supraventricular tachycardias, atrial flutter and sinus tachycardia c. Test sinoatrial conduction d. Test AV node function e. Unmask a

15、ccessory bypass tracts AVNRT CONCLUSION You only see what you look for and you only look for what you know! Systematic approach Understanding of common (and not-so-common) arrhythmias Not all rhythm disorders produce symptoms View the rhythm in the context of the patients overall condition: treat the patient, not the tracing! AFIB AH J