SPDX: ECG

• 1768 - Luigi Aloisio Galvani did the frog experimenT.
• 1842 - Italian scientist Carlo Matteucci realizes that electricity is associated with the heartbeat.
• 1876 - Irish scientist Mary analyzes the electric pattern of frog's heart.
• 1895 - William Einthoven, credited for the invention of EKG
• 1924 - the noble prize for physiology or medicine is given to William Einthoven for his work on EKG
• 1938 - AHA and Cardiac society of Great Britain defined and position of chest leads
• 1903 - William Einthoven invented first electrocardiogram
• 1925 - Einthoven gets nobel peace prize in medicine
• Electrocardiogram is a graphic recording of the electrical activity of the heart.
• Electrocardiogram converts the heart’s electrical activity into lines called “waveforms".
• Electrocardiogram can be seen on a monitor or printed out paper.
• Electrodes are applied at specific locations on the patient's chest wall and extremities to view the heart's electrical activity from different angles and planes.
• ECG paper is a graph paper used to measure rates of impulse formation and the duration of the electrical events that occur in the heart
• ECG paper is made up of vertical and horizontal lines, which form large and small boxes.
• A 12-lead electrocardiogram is a medical test that is recorded using leads, or nodes, attached to the body. Electrocardiograms, sometimes referred to as ECGs, capture the electrical activity of the heart and transfer it to graphed paper.
• The ECG is made up of 12 characteristic views of the heart: 6 from limb leads
• The ECG is made up of 12 characteristic views of the heart: 6 from chest leads
• 6 CHEST LEADS: V1- Electrode positioned in the 4th intercostal space in the right sternal border
• 6 CHEST LEADS: V2- 4th ICS in the left sternal border
• 6 CHEST LEADS: V3- Midway between V2 and V4
• 6 CHEST LEADS: V4- 5th ICS in the left midclavicular line
• 6 CHEST LEADS: V5- Same level as V4, anterior axillary line
• 6 CHEST LEADS: V6- Same level as V4 and V5 ,midaxillary line
• The P wave is the first positive deflection on the ECG.
• P wave represents atrial depolarization / contraction.
• Normal duration of P wave: < 0.12 s (< 120ms or 3 small squares)
• In a sinus rhythm, there should be a P wave before each QRS complex
• QRS COMPLEX represents ventricular depolarization.
• Q wave is the first negative deflection.
• R wave is the first positive deflection after the P wave.
• S wave is the negative deflection following R wave.
• PR INTERVAL is measured from the beginning of P wave to the beginning of QRS complex.
• The normal PR interval is 0.12 - 0.2 sec, represented by 3-5 small squares.
• ST SEGMENT is an isoelectric line representing early ventricular repolarization.
• The T wave is the positive deflection after each QRS complex.
• T wave represents ventricular repolarisation.
• U WAVE results from slow repolarization of ventricular Purkinje fibers.
• The U wave is a small (0.5 mm) deflection immediately following the T wave, usually in the same direction as the T wave.
• QT INTERVAL represents total time required for ventricular depolarization & repolarization from the beginning of QRS complex to the end of T wave.
• normal QT interval is 0.36 to 0.45 sec