Electrocardiography i May 2000 Final

Electrocardiography I

Drs.Drs.

J.G. De Lara Abad.J.G. De Lara Abad.

Manea Al ArashiManea Al Arashi

Al Azir Ayed.Al Azir Ayed.

The clinical electrocardiogram (ECG) records the

changing potentials of the electrical

fields imparted by the heart.

•Polarized state•Depolarization•Depolarized state•Repolarization

The normal heart beat is initiated by spontaneous firing of the sinus (SA) node in the right upper chamber of the heart (right atrium)

The activation wave passes through the muscles of both atria, activating them to contract

The electrical wave of activation reach the atrio- ventricular node

The activation rapidly descends the “Bundle of His”

The activation then spreads rapidly through the special conduction tissues of the ventricles

There follows a short period of relative inactivity recorded as the ST segment

Then the recovery wave spreads over the same pathway

“recharging the heart”

Sequence of ventricular activation of an isolated human heart

ECG Lead System

ECG Paper

ECG waves

ECG waves“ P “

ECG waves“QRS“

ECG waves“ T “

Report of ECG (1)

• Rhythm:

• Heart rates:

• Atrial

• Ventricular

• Axis Deviation

Report of ECG (2)

Measurements:

• PR:

• QRS:

• QT:

• QTc:

Report of ECG (3)

Description:

• I, II, III:

• aVR, aVL, aVF:

• V1 v2 :

Report of ECG (4)

Diagnosis:

According ECG, then with clinical findings.

Next classNext class

• Atrial enlargement• Ventricular hypertrophy

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