electrocardiograph

Electrocardiograph /ECG (Electrocardiogram) EKG

ECG is the graphical record of electrical activity of Heart.

ECG shows three principle deflection above and below the base line,

1. P wave

2. QRS complex

3. T wave

1. P wave

P wave is produce signal from SA node to AV node indicates, Atrium contraction (depolarization) both atria

2. QRS complex

When impulse travel the AV node to bundle branch and purkinje fibers.

Ventricle contraction (depolarization) both ventricle

3. T wave

T wave represents repolarization of ventricles.

4. S-T wave 

ST segment represents time duration which ventricles contract and eject blood .

ST segment indicate time interval between ventricular contraction to ventricular relaxation.

5. PR interval

Time taken for the impulse to travel from AV node to the bundle branches.

EGC provide a wealth of information about the normal electrical activity of Heart.

Deviation from normal can lead to various abnormoties in conduction pathways, myocardial infarction, enlargement of Heart and electrolyte and hormone imbalances.

P wave last about 0.8 sec (atrial contraction)

PR interval, about 0.16sec

QRS Complex, about 0.10sec

QT interval, is about 0.3 sec