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21/05/2013 2 ECG

ECG Recording:

21/05/2013 3 ECG Recording

ECG Components Diagram :

21/05/2013 4 ECG Components Diagram

ECG Intervals and Segments:

21/05/2013 5 ECG Intervals and Segments

Normal ECG Recording:

21/05/2013 6 Normal ECG Recording

The P wave:

21/05/2013 7 The P wave Represents atrial activation (atrial depolarization). Small +ve wave. Its amplitude 0.1 (up to 0.25) mv. Its duration 0.08 (up t0 0.11) seconds.

Abnormalities of P- wave:

21/05/2013 8 Abnormalities of P- wave In left atrial hypertrophy (due to mitral stenosis), the P wave become broad and notched. In right atrial hypertrophy (due to pulmonary hypertension) P wave become tall. In AV nodal rhythm: P wave inverted. In atrial fibrillation: P wave disappear.

The QRS complex:

21/05/2013 10 The QRS complex Represents ventricular activation (depolarization). The QRS duration is the duration of ventricular activation (0.06-0.1). Q wave: is –ve wave due to depolarization of interventricular septum. R wave : is a large +ve wave, its amplitude is 10 mm (1 mv), caused by depolarization of the apex and ventricular wall, it is + ve wave. S wave : is a –ve wave, caused by depolarization of the posterobasal part of the left ventricle and pulmonary conus.

Abnormalities of QRS complex:

21/05/2013 11 Abnormalities of QRS complex In ventricular hypertrophy. Infarction. Extrasystole. Bundle branch block. Electrolyte disturbance.

T wave:

21/05/2013 12 T wave It is a +ve large blunt wave. Represents ventricular activation (ventricular repolarization). Its amplitude 0.2 (up to 0.4) mv. Its duration 0.2 (up to 0.25) second.

Abnormalities of T wave:

21/05/2013 13 Abnormalities of T wave Inverted: Myocardial infraction. Ventricular hypertrophy. Extrasystole . Bundle branch block. Digitalis overdosage . 6- Pericarditis Increase amplitude: Sympathetic overactivity . Muscular exercise. Hyperkalemia

PowerPoint Presentation:

U wave

ECG Intervals and Segments :

21/05/2013 15 ECG Intervals and Segments

P-R interval:

21/05/2013 16 P-R interval - From the start of P-wave to the start of R wave. Its range from 0.12 to 0.21 second. It means conduction of cardiac impulse through A-V node. Abnormalities of P-R interval: 1- Prolonged: - First degree of heart block. - Increased vagal tone. 2 - Shortened: - A- V nodal rhythm. - Sympathetic overactivity. - Wolff- Parkinson- white syndrome.

Q-T interval:

21/05/2013 17 Q-T interval Start from the onset of Q wave to the end of T wave. Its duration 0.24-0.36 second. It is called electrical systole of the heart. T- Q interval: Start from the end of the T wave to the onset of the next Q wave. It is called electrical diastole. Its duration is about 0.4 second.

QT interval:

QT interval Prolonged QT : Familial long QT Syndrome (LQTS) Congestive Heart Failure Myocardial Infarction Hypocalcemia & Hypokalaemia Hypomagnesemia Type I Antiarrhythmic drugs & Cispride Rheumatic Fever Myocarditis Congenital Heart Disease Short QT : Digoxin ( Digitalis ) Hypercalcemia Hyperkalemia

S-T segment:

21/05/2013 19 S-T segment - Start from the end of S wave to start of T wave. Its duration is about 0.12. Abnormalities of S-T segment : Its deviation upward or downward indicates myocardial damage.

PowerPoint Presentation:

21/05/2013 21

PowerPoint Presentation:

21/05/2013 22

Heart Rate:

Heart Rate measurements


ECG PAPER Light lines small squares- 1 X 1 mm Bold lines large squares 5 X 5 mm Horizontal axis=time 1. Distance across small square=0.04 sec. 2. Distance across large square=0.2 sec. Vertical axis=voltage 1. Distance across small square=0.1 mV 2. Distance across large square=0.5 mV

PowerPoint Presentation:

For regular H.R. 15 cm

What is the heart rate?:

What is the heart rate? (300 / 6) = 50 bpm

What is the heart rate?:

What is the heart rate? (300 / ~ 4) = ~ 75 bpm

Normal H.R. 60-90 bpm Bradycardia less than 60 bpm Tachycardia less than 100 bpm:

Normal H.R. 60-90 bpm Bradycardia less than 60 bpm Tachycardia less than 100 bpm



Normal Sinus Rhythm – the rules!:

Normal Sinus Rhythm – the rules! P before every QRS PR interval <0.2 seconds (5 baby squares) QRS after every P wave QRS <0.12 seconds (3 baby squares) Regular and identical Rate 60-100 bpm <60 bpm – sinus bradycardia >100 bpm – sinus tachycardia

ECG Abnormalities:

21/05/2013 33 ECG Abnormalities

First degree AV block:

First degree AV block

Second degree AV block (mobitz I)-Wenckebach:

Second degree AV block (mobitz I)-Wenckebach

The ECG signs of Infarct!:

The ECG signs of Infarct! Abnormal Q waves ST segment elevation (Greater than 1mm in 2 or more adjacent leads) Inverted T waves

ST Elevation - Myocardial Infarction:

ST Elevation - Myocardial Infarction ST elevation in two or more leads Must be at least 1mm in limb leads Must be at least 2mm in chest leads

Characteristic changes in AMI:

Characteristic changes in AMI ST segment elevation over area of damage ST depression in leads opposite infarction Pathological Q waves Reduced R waves Inverted T waves

ST elevation:

ST elevation R P Q ST Occurs in the early stages Occurs in the leads facing the infarction Slight ST elevation may be normal in V 1 or V 2

Ventricular Fibrillation:

Ventricular Fibrillation Disordered ventricular impulses with no coordinated ventricular contraction No cardiac output occurs & pt immediately loses consciousness Can occur with any type of cardiac disease, electrolyte imbalance, hypoxemia, acidosis, shock, drugs ( epi , cocaine) ECG findings Chaotic, irregular complexes; no discrete QRS waveforms Rate: 350-450 bpm Can occur spontaneously or preceded by PVCs or VT Treatment Immediate defibrillation followed by anti-arrhythmic drugs to suppress further ventricular ectopy

Atrial flutter:

Atrial flutter

Atrial fibrillation:

Atrial fibrillation