Basic ECGBasic ECG

Mazen Tawfik, mdMazen Tawfik, md

Although Although AnatomicallyAnatomically the heart is composed of the heart is composed of 4 Chambers 4 Chambers (2 atria and 2 ventricles) (2 atria and 2 ventricles)

Yet, Yet, ElectricallyElectrically it is composed of it is composed of 2 Chambers2 Chambers. . The two atria stimulated together and the two The two atria stimulated together and the two ventricles also stimulated together.ventricles also stimulated together.There is complete separation between the atria There is complete separation between the atria and ventricles by and ventricles by central fibrous bodycentral fibrous body. The . The only connection between atria and ventricles is only connection between atria and ventricles is through the through the A-V nodeA-V node..

Anatomy of the HeartAnatomy of the Heart

Anatomy of the HeartAnatomy of the Heart

The conducting tissue is composed of The conducting tissue is composed of SA nodeSA node, , situated in the top of right atrium at the junction of situated in the top of right atrium at the junction of superior vena cava and the right atrium. superior vena cava and the right atrium. It is the It is the pacemaker of the entire heart. pacemaker of the entire heart. The The AV nodeAV node is situated at the base of the right atrium, is situated at the base of the right atrium, anterior to the ostium of the coronary sinus.anterior to the ostium of the coronary sinus.The The Bundle of HisBundle of His extends from the end of AV node extends from the end of AV node and branching to the right and left branches.and branching to the right and left branches.The The Purkinje fibersPurkinje fibers are terminal network of fibers that are terminal network of fibers that spreads the impulses directly to the ventricular walls. spreads the impulses directly to the ventricular walls. The specialized conducting tissue receives its The specialized conducting tissue receives its innervation from sympathetic and parasympathetic innervation from sympathetic and parasympathetic nervous system.nervous system.

The Conducting SystemThe Conducting System

The Conducting SystemThe Conducting System

The Conducting SystemThe Conducting System

Cardiac Action PotentialCardiac Action Potential

The E.C.G. PaperThe E.C.G. Paper

The Paper and the GraphThe Paper and the Graph

P - QRSTP - QRST

The ideal ECG commentThe ideal ECG comment

Heart rate.Heart rate.

Rhythm.Rhythm.

P wave.P wave.

PR interval.PR interval.

QRS : QRS : 1.1. AxisAxis

2.2. MorphologyMorphology

3.3. VoltageVoltage

4.4. DurationDuration

ST segment.ST segment.

T wave.T wave.

QT interval.QT interval.

10

15

Normal ECGNormal ECG

ObjectivesObjectives

ECG leads.ECG leads.

ECG recording.ECG recording.

ECG waves & intervals.ECG waves & intervals.

Calculation of Heart rate.Calculation of Heart rate.