ECG : a case based discussion
- 1. ECG Basics
- 2. 4 INITIAL FEATURES 4 WAVES 4 WIDTHS HISTORY P PR INTERVAL RATE QRS QRS WIDTH RHYTHM T ST SEGMENT AXIS U QT INTERVAL
- 4. WHAT DO THESE BOXES MEAN? BASIC PARTS OF AN ECG PAPER
- 8. Ecg waves and intervals BASIC PARTS OF AN ECG PAPER
- 13. WHAT DO YOU MEAN BY GROUPED LEADS? ALWAYS LOOK AT GROUPED LEADS TOGETHER – WHEN YOU LOOK AT LEAD 2, ALSO LOOK AT LEAD 3 AND avF AT THE SAME TIME. DON’T FORGET THIS RULE, EVER. NEXT SLIDE SHOWS THE RULE BETTER ALWAYS LOOK AT GROUPED LEADS TOGETHER – WHEN YOU LOOK AT LEAD 2, ALSO LOOK AT LEAD 3 AND avF AT THE SAME TIME. DON’T FORGET THIS RULE, EVER. NEXT SLIDE SHOWS THE RULE BETTER
- 15. ALWAYS LOOK AT GROUPED LEADS TOGETHER – WHEN YOU LOOK AT LEAD 2, ALSO LOOK AT LEAD 3 AND avF AT THE SAME TIME. DON’T FORGET THIS RULE, EVER. NEXT SLIDE SHOWS THE RULE BETTER WHAT DO YOU MEAN BY GROUPED LEADS?
- 17. Axis interpretation The most efficient way to estimate axis is to look at LEAD I and LEAD aVF. Examine the QRS complex in each lead and determine if it is Positive, Isoelectric (Equiphasic) or Negative:
- 18. • A positive QRS in Lead I puts the axis in roughly the same direction as lead I. • A positive QRS in Lead aVF similarly aligns the axis with lead aVF. • Combining both coloured areas – the quadrant of overlap determines the axis. So If Lead I and aVF are both positive, the axis is between 0° and +90° (i.e. normal axis). AXIS DETERMIN ATION
- 24. Each lead looks at heart from a different direction, and ‘captures’ electrical image, just like a DSLR camera. AXIS DETERMIN ATION
- 25. P wave abnormalities – P mitrale(shaped like a M) in Left atrial enlargement WAVE EXAMINATIO N – P WAVE
- 26. P wave abnormalities – P pulmonale(height of P increased) in rt. Atrial enlargement WAVE EXAMINATIO N – P WAVE
- 27. P wave - remember to see in lead II and V1 Increased height- right atrial enlargement Increased width- left atrial enlargement WAVE EXAMINATIO N – P WAVE
- 29. LVH WITH STRAIN PATTERN WAVE EXAMINATION – QRS WAVE
- 32. No elevation WAVE EXAMINATION – ST SEGMENT
- 39. ECG OF MI
- 40. ECG OF MI
- 41. SOME COMMON ECG BESIDES MI
- 42. 36-year-old male with hypertension and hypercholesterolemia presents to the emergency room with 3 hrs of chest pain and the following ECG. How would you manage this patient based on this ECG? a) Thrombolytic therapy b) Urgent cardiac angiography and stand-by angioplasty c) Conservative management with nonsteroidal analgesia d) Work-up for pulmonary embolism e) Urgent trans-esophageal echocardiogram
- 43. This patient's ECG is consistent with acute pericarditis. Always consider myocardial infarction first when you see ST elevations, but don't forget the differential diagnosis of ST elevations not only includes 1) ischemic heart disease (MI, Prinzmetal angina, ventricular aneurysm) but also 2) pericarditis, 3) left bundle branch block (LBBB) (in V1-V3) and 4) normal ("early repolarization") variant (J point elevation). In this ECG two features point to pericarditis: First, the diffuseness of the ST elevations (I, II, III, aVF, V3-V6). In myocardial infarction the ST elevations tend to be localized (inferior, anterior, posterior, lateral), often, but not always with reciprocal ST depressions.
- 44. Hyperkalemia (K+ = 8.7 mEq/L) secondary to acute renal failure. The ECG shows symmetrically peaked ("tented") T waves associated with potassium levels in excess of 6 mEq/L. The tracing also shows broad and flattened sinus P waves
- 45. Hyperkalemia (7.6 mEq/L), secondary to the renal failure. The ECG demonstrates findings consistent with severe hyperkalemia -- most importantly marked widening of the QRS complex. The QRS complex here shows an intraventricular conduction delay (IVCD) with a left bundle branch block (LBBB) morphology and left axis deviation. There is also peaking of the T waves with prolongation of the PR interval and flattening of the P waves. If the hyperkalemia is left untreated, the ECG will progress to a sinusoidal pattern and eventually asystole with subsequent hemodynamic collapse and death. The patient is an elderly man who presented to the emergency ward with dizziness and new renal failure. What is the cause of the very wide QRS?
- 47. ECG Features of Atrial Fibrillation • Irregularly irregular rhythm • No P waves • Absence of an isoelectric baseline • Variable ventricular rate • QRS complexes usually < 120ms, unless pre-existing bundle branch block, accessory pathway, or rate-related aberrant conduction • Fibrillatory waves may be present and can be either fine (amplitude < 0.5mm) or coarse (amplitude > 0.5mm) • Fibrillatory waves may mimic P waves leading to misdiagnosis
- 48. ECG Features of Atrial Fibrillation
- 49. ECG Features of Atrial Fibrillation
- 50. ECG features of atrial flutter • Narrow complex tachycardia • Regular atrial activity at ~300 bpm • “Saw-tooth” pattern of inverted flutter waves in leads II, III, aVF • Upright flutter waves in V1 that may resemble P waves • Loss of the isoelectric baseline • Ventricular rate depends on AV conduction ratio
- 53. Supraventricular tachycardia(AVNRT) ◦ ECG features of AVNRT • Regular tachycardia ~140-280 bpm • Narrow QRS complexes (< 120ms) • P waves may be buried within, visible after, or very rarely visible before the QRS complex Supraventricular tachycardia (SVT): Rhythm strip demonstrating a regular, narrow-complex
- 54. THAT’S ALL!