Electrocardiogram PDF

# Electrocardiogram By Asst. Lecturer Zainab Hamid ## ECG(electrocardiograph) - ECG is define as "recording of electrical activity of heart on a graph paper." - Or - Graphical representation of electrical activity of heart. ## INTRODUCTION - ECG is a three letter acronym for ElectroCardioGraphy...

# Electrocardiogram By Asst. Lecturer Zainab Hamid ## ECG(electrocardiograph) - ECG is define as "recording of electrical activity of heart on a graph paper." - Or - Graphical representation of electrical activity of heart. ## INTRODUCTION - ECG is a three letter acronym for ElectroCardioGraphy. - The word is derived from *electro*(greek for electricity),*cardio*(greek for heart) and *graph*(Greek root meaning "to write"). ## Significance of ECG - ECG gives information about rate and rhythm of the heart. - The physical orientation of heart i.e axis. - Its a diagnostic tool for various heart conditions like hypertrophies, ischemia, infarction, arrhythmias conduction problems and pace maker activity. - ECG does not provide information about mechanical activity. ## ECG paper - This is long role of paper, composed of small squares. - One square is 1mm wide and 1 mm high. - On ECG paper there are thick lines, between two thick lines there are 5 small squares. - The speed of ECG machine is 25 mm per second. ## ECG Paper: Dimensions A diagram showing the dimensions of an ECG paper. The following information is visible: - 5mm - 1mm - Voltage ~Mass - 0.1 mV - 0.04 sec - 0.2 sec - Speed = rate ## ECG Paper - The time internal of each small square can be calculated as - 25 small sqrs are equal to 1 second. - 1 small sqr is equal to 1/25 second. - i.e 0.04 seconds. ## ECG paper - vertically the small square represent the amount of electrical potential. - One small sqr represent the potential of 0.1 mv. - 10 small squares represent the potential of 1 mv. ## Normal ECG A diagram of a normal ECG with the following labels: - QRS Complex - R - PR Segment - ST Segment - T - P - PR Interval - Q - S - QT Interval ## Waveforms in ECG A diagram of an ECG waveform with the following labels: - QRS complex - T wave - P wave The electrical activity of the cardiac cycle is characterized by five primary wave deflections, designated by letters P, Q, R, S, T. ## ECG leads - leads are electrodes which record the electrical potential of heart at different sites. - There are 12 ECG leads. - 3 bipolar limb leads. - 3 augmented limb leads. (unipolar). - 6 chest leads. ## Summary of Leads | | Limb Leads | Precordial Leads | |-------|-------------------------|-----------------| | Bipolar| I, II, III | - | | | (standard limb leads) | | | Unipolar| aVR, aVL, aVF | V₁-V₆ | | | (augmented limb leads)| | ## Anatomic Groups | | aVR | V₁ | V₄ | |---|---|-------|-------| | I | | V₂ | V₅ | | II| | V₃ | V₆ | | | Inferior Leads | Septal Leads | Anterior Leads | Lateral Leads | ## ELECTROCARDIOGRAPHY - A typical ECG reading showing **Normal Sinus Rhythm** - A typical ECG reading showing **Ventricular Tachycardia** - A typical ECG reading showing **Ventricular Fibrillation** ## ST Elevation A typical ECG reading showing **ST Elevation**. ## ST Depression A typical ECG reading showing **ST Depression**. ## Thank you A simplified ECG reading showing a normal rhythm: - "with you" - "without you"