1. Heart Anatomy + ECG Aaqid Akram MBChB (2013) Clinical Education Fellow

3. Brachiocephalic Trunk L Subclavian Artery L Common Carotid Artery Arch of the Aorta Superior Vena Cava Pulmonary Artery L Pulmonary Vein L Atrium Mitral Valve (Bicuspid) Chordae Tendinae Papillary Muscle Endocardium Myocardium Septum Aortic Valve (Semilunar) Inferior Vena Cava L Ventricle R Ventricle Tricuspid Valve Pulmonary Valve R Atrium Fossa Ovalis

4. Ligamentum Arteriosum R Coronary Artery Circumflex Artery L Anterior Descending Artery

6. Cardiac Cycle

7. Introduction Wash Hands Introduce yourself Confirm patient + ALLERGY STATUS Explain investigation to patient Gain verbal consent Offer chaperone (Chest will be exposed) – If opposite sex you require a chaperone for your own safety

8. The ECG Machine Power (plugged/battery) Demographics Paper All leads intact Stickers available Scale – vertical axis (0.1mV = 1mm = 1 small square)

9. Placing Stickers

10. There’s only 10 leads…. How can it be a 12 lead ECG?

12. Interpreting an ECG Demographics Obvious abnormality Rate Rhythm Axis P wave PR Interval QRS Complex ST segment T wave Summary

13. Rate 1500 small squares (0.04 seconds) = 60s No of small squares between R-R = x 1500/x = ventricular rate per minute If normal calibration  rhythm strip = 50 large squares (0.2seconds) = 10 seconds Count QRS complexes on rhythm strip Multiply by 6 = ventricular rate per minute

14. Rhythm Sinus = p wave before every QRS Complex Regular = QRS complexes equidistant – Mark 3 R-R points on the edge of a paper – Move to next three complexes – Do the marks on the paper correlate to the R waves?

15. Axis

16. P Wave T Wave

17. P wave Atrial depolarisation (Sino Atrial Node) 2-3 mm high 0.06 – 0.12 seconds duration Usually positive deflection throughout ECG Peaked/enlarged = atrial hypertrophy Inverted = retrograde/reverse conduction Absent = conduction by route other than SA

18. PR Interval Impulse from atria to AV Node, Bundle of His, bundle branches 0.12 – 0.2 seconds duration Short = impulse did not originate from SA Long = AV Block

19. 1 st Degree Heart Block 1 st Degree: – QRS complex after every P wave – Prolonged PR Interval – No Rx necessary unless symptomatic

20. 2 nd Degree Heart Block Mobitz Type 1 (Wenckebach): – Each successive impulse from SA node delayed slightly longer than previous impulse – A QRS complex is dropped – Cycle repeats

21. 2:1 Heart block xx x x xx Mobitz Type 2: – Occasional SA impulses fail to cause ventricular depolarisation – Regular P waves, but some dropped QRS complexes 2 nd Degree Heart Block

22. 3 rd Degree Heart Block Complete Heart Block: – Impulses from atria cannot pass the AV node – Atria depolarise independently to ventricles – Life threatening

23. QRS Complex Deep wide Q waves may suggest old infarct Total duration <0.12 seconds >0.12 seconds = ventricular conduction delay

24. Bundle Branch Block Bundle branch fails to conduct impulses Ventricles contract at slightly different times Block further down the bundle = hemiblock Cell-cell conduction slower than via specialised pathway therefore prolonged depolarisation New Left Bundle Branch Block = ACS

26. QT Interval Time from ventricular depolarisation to ventricular repolarisation Varies according to heart rate QTc = corrected QT interval to 60bpm Males <450 ms / Females <470 ms Prolonged QT interval increases risk of life threatening arrhythmias

27. Torsades de Pointes

28. Drugs affecting QT Interval DrugType AmiodaroneAntiarrhytmic AmitriptyllineAntidepressant ChlorpromazineAntipsychotic/antiemetic ClarithromycinAntibiotic DroperidolSedative/antiemetic ErythromycinAntibiotic FluoxetineAntidepressant HaloperidolAntipsychotic KetoconazoleAntifungal LevofloxacinAntibiotic MethadoneOpiate agonist QuinidineAntiarrhythmic SertralineAntidepressant SotalolAntiarrhythmic SumatriptanAnti migraine

29. ST Segment Segment affected if acute ischaemia/infarction Elevation = >1mm Depression = >0.5mm

33. T Wave Ventricular repolarisation Usually upright deflection Tented T waves = hyperkalaemia/myocardial injury Inverted T wave = ischaemia Camel Hump = hidden P/U wave

36. Summary Present all positive findings and important negative findings. Advise on urgency of management.

37. Supraventricular Tachycardia

38. Atrial Flutter

39. Atrial Fibrillation

40. Ventricular Tachycardia

41. Ventricular Fibrillation

42. Asystole

43. Any Questions? Thank You