Dr.H. Bayu Samudra

Conduction System

SA Node Internodal branch AV Node Hiss Bundle Purkinje Fiber Contraction

The Electrocardiogram ( ECG )The Electrocardiogram ( ECG )

• P wave : atrial depolarisation

• QRS complex : ventricular depolarisation

• T wave : ventricular repolarisation

• Atrial repolarisation hidden by QRS

P

Q

R

S

T

P Wave

P Pulmonale

P Mitrale

PR Interval

QRS Complex

ST Segment

T Wave

Normal Sinus Rhythm

Rhythm : RegularRate : 60 – 100P wave : Normal in configuration; precede each QRSPR : Normal ( 0. 12 – 0.20 seconds )QRS : Normal ( less than 0.12 seconds )

First-degree AV block

Rhythm : RegularRate : Usually normalP wave : Sinus P wave present; one P wave to each QRSPR : Prolonged ( greater than 0.20 seconds )QRS : Normal

Second -degree AV block, Mobitz I

Rhythm : IrregularRate : Usually slow but can be normalP wave : Sinus P wave present; some not followed by QRS complexesPR : Progressively lengthensQRS : Normal

Second-degree AV block, Mobitz II

Rhythm : Regular usually; can be irreguler if conduction ratios varyRate : Usually slowP wave : Two, three, or four P waves before each QRSPR : PR interval of beat with QRS is constant; PR interval may be normal or prolongedQRS : Normal if block in His bundle; wide if block involves bundle branches

Third-degree AV block

Rhythm : RegularRate : 40 – 60 if block in His bundle; 30 – 40 if block involves bundle branchesP wave : Sinus P wave present; bear no relationship to QRS; can be found hidden in QRS complexes and T wavesPR : Varies greatlyQRS : Normal if block in His bundle; wide if block involves bundle branches

Wolff-Parkinson-White syndrome

ST depresi dan perubahan gelombang T

• ST depresi dianggap bermakna bila > 1 mm di bawah garis dasar PT di titik J• Titik J didefinisikan sebagai akhir kompleks QRS dan permulaan segmen ST

Bentuk segmen ST :

• up-sloping ( tidak spesifik )• horizontal ( lebih spesifik untuk iskemia )• down-sloping ( paling terpercaya untuk iskemia )

Perubahan gelombang T pada iskemia kurang begitu spesifik Gelombang T hiperakut kadang2 merupakan satu-satunyaperubahan EKG yang terlihat

Anatomi Koroner dan EKG 12 sandapan

• Sandapan V1 dan V2 menghadap septal area ventrikel kiri

• Sandapan V3 dan V4 menghadap dinding anterior ventrikel kiri

• Sandapan V5 dan V6 ( ditambah I dan avL ) menghadap dinding lateral ventrikel kiri

• Sandapan II, III dan avF menghadap dinding inferior ventrikel kiri

Unstable angina

Acute anteroseptal myocardial infarction. Hyperacute T-wave changes are noted

Acute anterolateral myocardial infarction

High lateral infarction

Inferior myocardial infarction

Acute inferoposterior myocardial infarction

L V H

L V H

L V H

R V H

R V H

R V H