ECG Presentation by Dr Haitamba and Dr Pallais.pptx

Ecg presentation

1. Electrocardiography Presenters: Dr Haitamba & Dr Pallais Bachelor of Medicine & Surgery MBChB School of Medicine – UNAM Intermediate Hospital Oshakati

2. Outline Basics Stepwise approach to ECG reading. Identify common ECG abnormalities. Criteria for common ECG findings Clinical application of ECG

3. Electrocardiography ECG is a 3-letter acronym for ElectroCardioGraphy . Electro: electricity Cardio: heart Graph: to write It is a transthoracic interpretation of the electrical activity of the heart over time captured and recorded. ECG is the gold standard for the non-invasive diagnosis of cardiac diseases. This technology is used every day nowadays, but it took a lot of scientists, inventors, and even frogs to get to where ECGs are today.

4. Why an ECG? Cardiac arrythmias Myocardial Infaction Cardiac myopathies Electrolyte imbalances Intraoperative Drug effects & Toxicity

5. 12 – Lead ECG

6. Approach Look for standardization and aVR (confirm the right lead placement) Rate Rhythm Axis P-wave morphology & QRS- complex P-R interval Bundle branch blocks ST-segment and T-wave changed Hypertrophy

7. Interpretation “a matter of pattern recognition.” Demographics: Name, ID, Age & Sex Standardization: confirm aVR and correct placement of leads

8. Physiology

9. Heart Rate Regular Irregular

10. Electrical Axis… Other way of getting the axis: Use Thumb Rule : Where the left thumb represent lead I Right thumb represents lead aVF The axis levelled based on the upright thumb both thumbs up  normal axis Only left thumb up left axis Only right thumb up right axis Both down  extreme axis deviation

11. Nuggets Rhythm: distance between QRS complexes. If equal=regular; if not, irregular P wave: smooth, round & upright. (0.08-0.2sec) PR Interval: within 3 – 5 small boxes; 0.12 – 0.20 seconds QRS Complex: narrow, steep angle & sharp points. ST segment: Isoelectric line; within 5 small boxes –0.20secs T wave: asymmetrical QT Interval: shows ventricular action; 0.33 – 0.44 secs U wave: No clinical significance. Purkinje fibres’ repolarization

12. P-R Interval Normal P-R interval is 0.12- 0.2 seconds (3-5mm) P-R interval is best appreciated in rhythm strip Causes of short P-R interval (P-R<11 seconds): Retrograde junctional P-wave Wolf Parkinson white pattern and syndrome (WPW) Causes of prolonged P-R > 0.2 seconds): Heart blocks 1 st , 2 nd , and 3 rd degree heart blocks)

13. P- Mitrale or Left Atrial Enlargement Criteria : The P-wave in lead II is > 0.12 sec and notched (M-shaped) The gap between the two peaks should be greater than 0.04 seconds Concept : The left atrium is enlarged and the duration to depolarize the left atrium is prolonged compared to the right atrium resulting in a notched and wide P-wave. Causes : Left atrial hypertrophy, MR, MS Hypertension Hypertrophic cardiomyopathy

14. P-Pulmonale or Right Atrial Enlargement The P-wave is peaked, and the amplitude is >2.5mm in lead II Because of the right atrial enlargement, the duration required for the right atrium to depolarize is longer, hence the tall p-wave Causes : Right atrial hypertrophy Cor pulmonale Pulmonary hypertension Congenital Heart Disease: Pulmonary stenosois TOF, Tricuspid stenosis

15. Brady Arrythmias Sinus Bradycardia

16. First Degree Heart Block…. Causes of first degree AV block: Normal physiological variantVasovagar reaction R heumatic fever drugs such as beta blockers, calcium channel blockers, digitalis L ife threatening conditions: MI, hyperkalemia, hypermagnesaemia T reatment: adress underlying condition

17. Second Degree Heart Block Mobith type I b lock: The block is proximal to the bundle of his I t is generally benign, unless the patient is symptomatic Common causes are the same as that of first degree AV block

18. Second Degree Heart Block Mobith type II : the block is distal to the bundle of his PR interval is normal but the P-waves are more than the QRS since some QRS complexes are dropped . U sually caused by disease of the left coronary artey A tropin is not usaully effective P acing is usually indicated Adrenaline or dopamine infusion can also be used if pacing is not successful

19. Third Degree Heart Block…. Clinical presentation : Blackout, dizziness and sudden loss of consciousness or syncope Usually bradycardia <40 bpm Blood pressure: high pulse pressure (high systolic and normal diastolic) JVP: Cannon waves ( large a- waves) can be present Usually caused by disease of the left coronary artery Occasionally caused by digitalis Pacing is indicated; atropine is not effective unless it is a narrow complex QRS If pacing is ineffective or unavailable, co n sider adrenaline or dopamine infusion.

20. Third Degree Heart Block….

21. Right Bundle Branch Block (RBBB) Criteria: Wide QRS complex rSR pattern or rabbit ear pattern in V1 Broad and slurred S wave in leads I and V6 Right axis deviation may be present

22. Left Bundle Branch Block (LBBB) The right bundle branch has no main divisions, but the left bundle branch has two– the anterior and posterior ‘fascicles’ The depolarization wave therefore spreads into the ventricles by three pathways The cardiac axis depends on the average direction of depolarization of the ventricles Since the left ventricle contains more muscle than the right, it has more influence on the cardiac axis If the anterior fascicle of the left bundle branch fails to conduct, the left ventricle has to be depolarized through the posterior fascicle and so the cardiac axis rotates upwards

23. Effect of left Anterior Fascicular Block Left axis deviation is therefore due to left anterior fascicular block , or ‘left anterior hemi-block’ The posterior fascicle of the left bundle is not often selectively blocked, but if this does occur the ECG shows right axis deviation

24. Tachyarrthymias

25. Tachyarrythmias

26. Supraventricular tachycardia Treatment : Vagal stimulation : vAlsalva manoeuvres ; Ice water; Carotid Sinus Massage Adenosine If recurrent: Beta blockers, Calcium channel blockers, Amiodarone, elective synchronised carioversion R adiofrequency ablation of the accessary pathway

27. Hypertrophy Left ventricular hypertrophy Criteria: Sokolow Lyon Criteria: Sum of the depth of S-wave in V1 and R wave in V5 or V6 > 35mm or R-wave in V5 or V6 > 26 ( more sensitive) Any precordial lead > 45mm The R-wave in aVL > 11mm The R- wave in lead I > 12mm The R-wave in aVF > 20mm

28. Hypertrophy… Right Ventricular Hypertrophy Criteria: R V1 divided by S V1 should be > 1 (more sensitive) R wave in V1 plus S wave in V5 or V6 =11 (Sokolow-Lyon criteria) R in aVR should be > 5mm R wave in V1 = 7mm S wave in V1 = 2mm

29. References A guide to the management of common medical emergencies in adults, 11 th edition, 2017 ECG Pictures of patients at IHO 2024 Learn ECG in a day, a systematic approach, Jaypee Brothers Medical Publishers 2013. Lecture on ECG by Dr Fasika for MBChB IV 2021

30. Tangi…