Clinical approach to common electrocardiography.pptx

A presentation on how to approach ecgs and interpret them.

1. Approach to Common ECGs

2. Electrocardiography Is transthoracic interpretation of the electrical activity of the heart over time captured and externally recorded by skin electrodes for diagnostic or research purposes on human hearts.

3. The graph paper recording produced by the machine is termed an electrocardiogram, It is usually called ECG or EKG

4. Normal segments, intervals and mechanism

5. Rate Rhythm Cardiac Axis P – wave PR - interval QRS Complex ST Segment Other ECG signs Interpret ECG in a step wise manner:

6. RATE

7. As a general interpretation, look at lead II at the bottom part of the ECG strip. This lead is the rhythm strip which shows the rhythm for the whole time the ECG is recorded. Look at the number of square between one R-R interval. To calculate rate, use any of the following formulas: CALCULATING RATE

8. FOR EXAMPLE:

9. If you think that the rhythm is not regular , count the number of electrical beats in a 6-second strip and multiply that number by 10. Example below: There are 8 waves in this 6-seconds strip.

10. RHYTHM

11. Look at p waves and their relationship to QRS complexes. Lead II is commonly used Regular or irregular? If in doubt, use a paper strip to map out consecutive beats and see whether the rate is the same further along the ECG. Measure ventricular rhythm by measuring the R-R interval and atrial rhythm by measuring P-P interval.

12. Tachyarrhythmias

13. Common Ones

14. Cardiac Axis

15. To determine cardiac axis look at QRS complexes of lead , II, III. Remember, positive(upgoing) QRS complex means the impulse travels towards the lead. Negative means moving away.

16. Normal Axis

17. Left Axis Deviation

18. Right Axis Deviation

19. P wave

20. The P wave is the first positive deflection on the ECG It represents  atrial depolarisation Normal duration: < 0.12 s (< 120ms or 3 small squares) P wave

21. Common P Wave Abnormalities: P  mitrale  (bifid P waves), seen with left atrial enlargement P  pulmonale  (peaked P waves), seen with right atrial enlargement P wave inversion, seen with ectopic atrial and junctional rhythms Variable P wave morphology, seen in multifocal atrial rhythms

22. PR Interval

23. First Degree Heart Block

24. Second Degree Heart Block

25. Second Degree Heart Block

26. Third Degree Heart Block (Complete)

27. QRS Complex

28. QRS Complex Naming Convention

29. ST SEGMENT

30. For simplicity 2020 ESC Guidelines

31. Antero- Lateral Wall MI

32. Inferior Wall MI

33. NSTE-ACS

34. To determine LVH, use one of the following Criteria: Left Ventricular Hypertrophy S (V1) + R(V5) = 15 + 25 = 40mm S(V3) + R (aVL)= 15 + 14 = 29mm R( aVL ) = 14 mm Hence is LVH !!!

35. Tall R waves in V4 and V5 with down sloping ST segment depression and T wave inversion. Suggestive of left ventricular hypertrophy ( LVH) with strain pattern. LVH with strain pattern usually occurs in pressure overload of the left ventricle as in systemic hypertension or aortic stenosis.

36. Diagnostic criteria Right axis deviation of +110° or more. Dominant R wave in V1 (> 7mm tall or R/S ratio > 1). Dominant S wave in V5 or V6 (> 7mm deep or R/S ratio < 1). QRS duration < 120ms (i.e. changes not due to RBBB). Right Ventricular Hypertrophy

37. Other common ECG signs

38. Hyperkalemia Hypokalemia

39. Hyper/Hypocalcemia

40. M/C is Sinus Tachycardia Very specific: S1Q3T3 Pattern Signs of RV Strain and Ischemia ie T wave inversions in V1-V4 Pulmonary Embolism

41. Thankyou