Ecg ppt

Electrocardiography/ ecg

1. Electrocardiography PREM (2015A5PS862H) BITS PILANI HYDERABAD CAMPUS

2. What is ECG ? Electrocardiography  ( ECG  or  EKG ) is the process of recording the electrical activity of the heart over a period of time. Electrical activity recorded by using  electrodes placed on a patient's body. These electrodes detect the tiny electrical changes on the skin that arise from the heart muscle depolarizing during each  heartbeat.

3. Normal Impulse Conduction Senatorial node AV node Bundle of His Bundle Branches Purkinje fibers Copyright@ embryology.med.unsw.edu.au

4. Impulse Conduction & ECG Senatorial node AV node Bundle of His Bundle Branches Purkinje fibers Copyright@ columbiasurgery.org

5. Copyright@ embryology.med.unsw.edu.au

6. The “PQRST” P wave – Atrial depolarisation. QRS – Ventricular depolarisation. T wave – Ventricular repolarisation. The PR interval - Atrial depolarisation + delay in AV junction The QT interval – Repolarisation of Ventricle + depolarisation of Ventricle

7. Lead Placement In a conventional  12 lead ECG , ten electrodes are placed on the patient's limbs and on the surface of the chest.  Copyright @ecg.utah.edu

8. The overall magnitude of the heart's electrical potential is then measured from twelve different angles and is recorded over a period of time (usually 10 seconds )   The overall magnitude and direction of the heart's electrical depolarization is captured at each moment throughout the cardiac cycle. The graph of  voltage versus   time  produced by this  medical procedure is referred to as an  electrocardiogram.

9. The ECG Paper Horizontally - One small box - 0.04 s One large box - 0.20 s Vertically - One large box - 0.5 mV Copyright@ embryology.med.unsw.edu.au

10. Rate Rule of 300- Divide 300 by the number of boxes between each QRS = rate. (300 / 6) = 50 bpm Copyright@ commons.wikimedia.org

11. HR of 60-100 per minute is normal HR > 100 = tachycardia HR < 60 = bradycardia

12. References: www.google.com https:// en.wikipedia.org/wiki/Electrocardiography BITS –Pilani Library http://www.ozemedicine.com/wiki/doku.php?id=ecg_easy https://commons.wikimedia.org/wiki/File:ECG_principle_slow.gif