210 likes | 355 Views
Electrocardiogram. Prepeared By Dr: Manal Moussa. Electrocardiogram Definition: ECG is a graphic record of the electrical currents that are generated by the heart. Purposes: The nurse performs a 12- lead ECG to: 1- Provide information about the electrical system of the heart.
E N D
Electrocardiogram Prepeared By Dr: Manal Moussa
Electrocardiogram Definition: ECG is a graphic record of the electrical currents that are generated by the heart.
Purposes: The nurse performs a 12- lead ECG to: 1- Provide information about the electrical system of the heart. 2- Record cardiac electrical activity for diagnostic or documentary reasons. 3- Diagnose myocardial infarction. 4- Detect cardiac enlargement. 5- Differentiate between different types of dysrrhythmias. 6- Determine the effects of administered drugs and/or electrolytes on the heart's electrical system.
Conductive system of the heart: *The Sino Atrial node (S.A node) has the highest rate of depolarization in the whole system. It starts each heart beat (pace maker). *From the S.A node, the impulse spreads to the atria through Bachmann's Bundle to the left atrium. *Stimulation of the atria produces the P wave on the ECG. After that a brief delay at the atrioventricular node (A.V node) to allow the atria sufficient time to squeeze additional blood into the ventricles.
*Then the impulse travels to the Bundles of His • down the left and right bundle branches and • terminates in the Purkinje fibers resulting in • contraction of the ventricles. • * The result of electrical stimulation of the • ventricles produces QRS complex on ECG. • *After that the relaxation of the cardiac muscle • occurs which represent T wave in ECG.
-Interpretation of ECG leads: Bipolar limp leads:* Lead I (LI): When the ECG is attached to the right and left arms. It represents the difference in electrical impulse between these two points. Lead II (LII): When the ECG is attached to the right arm and left leg. It represents the difference in electrical impulse between these two points. Lead III (LIII): When the ECG is attached to the left arm and left leg. It representsthe difference in electrical impulse between these two points.
aVR: Located in right arm. Records the changes in electrical current occurring in the part of heart which faces the right shoulder. aVL: Located in left arm. Records the changes in electrical current occurring in the part of heart which faces the left shoulder. aVF: Located in left leg. Records the changes in electrical current occurring in the part of heart which faces the left leg.
Chest or precordial leads: Chest leads: V1-----fourth intercostals space (ICS) at right sternal border. V2-----Fourth ICS at left sternal border. V3-----Midway between V2 and V4. V4-----Fifth ICS at midclavicular line. V5-----Left anterior axillary line at level of V4. V6-----Left midaxillary line at level of V4 horizontally.
V. Documentation: Record in the patient's chart: -Patient's name. -Age. -Diagnosis. -Date. -Time of procedure.
Rule of 300- Divide 300 by the number of boxes between each QRS = rate