ECG ARTIFACTS AND PITFALLS

HOW TO DIAGNOSE AND AVOID THESE COMMON ERRORS WHILE DOING AND INTERPRETING ECG

1. ECG ARTIFACTS AND PITFALLS DR PADMANABH KAMATH ADDITIONAL PROFESSSOR DEPT OF CARDIOLOGY KMC MANGALORE

2. STANDARD POSITION OF LEADS

3. 10 COMMANDMENTS YOU SHALL NOT REVERSE THE ARM ELECTRODES YOU SHALL NOT TREAT THE ECG,TREAT PATIENT SHALL NOT REVERSE LG ELECTRODES SHALL NOT REVERSE PRECORDIAL ELECTRODES PATIENT CALM AND QUIET TURN OFF MOBILE PHONE DO NOT PLACE ELECTRODE ON TORSO DO NOT PLACE TELEMETRY ELECTRODES ON ECG ELECTRODES DO NOT REVERSE ARM AND LEG ELECTRODES PATIENT SHOULD BE LYING DOWN

4. CLASSIFICAION OF ARTIFACTS INTERNAL( PHYSIOLOGICAL ) MUSCULAR MOTION EXTERNAL( NON PHYSIOLOGICAL ) ELECTROMAGNETIC INTERFERENCE Light Electrocautery Electrical devices CABLE AND ELECTRODE MALFUNCTION Insufficient gel Inappropriate filter Loose connection Misplaced leads Accumulation of static energy

5. LIMB LEAD REVERSAL

6. RA LA LEAD REVERSAL(COMMONEST ) ( T echnical D extrocardia )

7. TECHNICAL DEXTROCARDIA R wave positive in lead avR Extreme axis eviation Reverse polarity in all normal deflection in lead I and avL DIFFERENTIAL IS DEXTROCARDIA In dextrocardia precordial R wave progression is reversed In technical dextrocardia it is normal.

8. RA AND RL REVERSAL ( pseudoasystole pattern )

9. LEFT ARM AND LEFT LEG REVERSAL ( abdollah sign )

10. REVERSAL OF PRECORDIAL LEADS ( Tall R in V1and deep S in V6 )

11. TREMOR ARTIFACT ( Pseudo flutter waves ) When in doubt look at lead II

12. ERROR OF COMPUTER AVERAGING ( HI TECH ARRHYTHMIAS )

13. PSEUDO VENTRICULA TACHYCARDIA ( SINUS SIGN,SPIKE SIGN,NOTCH SIGN )

14. Differentiating an Artifact from Ventricular tachycardia Huang et al also described 3 signs that may help in differentiating a tremor-induced pseudo-ventricular tachycardia from true ventricular tachycardia. Presence of any of these signs is suggestive of pseudo-ventricular tachycardia : "Sinus" sign: One of the frontal leads (I, II and III) may present with sinus rhythm showing normal P, QRS, and T waves. The reason is that one of the upper limbs may be free off tremor . "Spike" sign: Presence of regular or irregular tiny spikes among wide-QRS complexes . "Notch" sign: Notches superimposed in the wide-QRS-like complex artifact, coinciding with the cycle length when sinus rhythm was recorded.

15. WANDERING BASELINE ECG

16. WANDERING BASELINE CAUSES: EXAGGERATED RESPIRATORY MOVEMENTS USUALLY SEEN IN PATIENTS IN RESPIRATORY DISTRESS . SOLUTION: AVOID PLACING ELECTRODE IN AREAS WHERE MOVEMENTS OF THE ACCESSORY MUSCLES ARE MOST EXAGGERATED . PLACE THE ELECTRODES ON THE TOP OF THE SHOULDERS.

17. Baseline drift The amplifier in the ECG machine has to re-find the 'mean '. This often occurs right after lead connection and after electric cardioversion.

18. ELECTROMAGNETIC INTERFERENCE ( CELL PHONES )

19. Differentiating an Artifact from Ventricular tachycardia Sometimes, EKG changes may mimic specific arrhythmias like ventricular tachycardia and atrial flutter or fibrillation. It is important to differentiate these, as misdiagnosis can lead to inadvertent use of medications and procedures in such a patient. Characteristics that can help in differentiate an artifact from ventricular tachycardia include: Absence of hemodynamic deterioration during the event. Normal QRS complexes within the artifact. An unstable baseline on the EKG before the event, after the event, or both. Association with bodily movement.

20. ELECTRICAL INTERFERENCE

21. ELECTRICAL INTERFERENCE CAUSES: PATIENT USING ELECTRICAL EQUIPMENT IMPROPERLY GROUNDED EQUIPMENT LOOSE ELECTRICAL CONNECTIONS OR EXPOSED WIRING. SOLUTIONS: (A) IF PATIENT IS USING ELECTRICAL EQUIPMENT, TO PUT OFF THE EQUIPMENT.PROBLEM IS TRANSIENT AND WILL CORRECT ITSELF. (B) IF PATIENT IS NOT USING ELECTRICAL EQUIPMENT UNPLUG ALL EQUIPMENT NOT IN CONTINOUS USE REMOVE FROM SERVICE AND USE BATTERY CONNECTION ASK THE ELECTRICAL ENGINEER TO CHECK THE WIRING.

22. CALM PATIENT!!!!!!

23. THANK YOU