Norm of Electrocardiography (ECG, EKG)
Normal sinus rhythm, no dysrhythmias.
Usage of Electrocardiography (ECG, EKG)
Anesthesia, angina pectoris, anxiety, atrial septal defect, beriberi, bradycardia, carbon monoxide poisoning, chest pain, coarctation of the aorta, congestive heart failure, dysrhythmias, effusion (pericardial), emergency monitoring, endocarditis, heart murmur, ischemia, myocardial infarction (MI), pacemaker function, palpitations, panic disorder, patent ductus arteriosus, pericarditis, preoperative evaluation, pulmonic stenosis, respiratory distress, surgery, syncope, tetralogy of Fallot, transposition of the great arteries, tricuspid atresia, ventricular hypertrophy, ventricular septal defect, and yellow fever.
Description of Electrocardiography (ECG, EKG)
Recording of the heart's electrical current using electrodes from 12 different leads: bipolar limb leads I, II, III; augmented limb leads aVR, aVL, aVF; and precordial chest leads V1-V6. The heart's electrical activity takes three forms on the ECG: the P wave, which signifies atrial depolarization; the QRS complex, which signifies ventricular depolarization; and the T wave, which signifies ventricular repolarization. This test identifies conduction abnormalities and dysrhythmias, monitors recovery from MI, and helps evaluate the effectiveness of cardiac medications. Single-lead tracings monitor the presence and type of electrical conduction during cardiac emergencies and during insertion of a temporary transvenous pacemaker.
Professional Considerations of Electrocardiography (ECG, EKG)
Consent form NOT required.
- The client should disrobe above the waist.
- Cleanse the skin where the electrodes will be placed by rubbing it lightly with an alcohol wipe and then scraping gently with the edge of an electrode.
- Check the paper supply.
- Single-channel recording:
- a. The client is positioned supine.
- b. Five electrodes are placed over clean fleshy skin with the conductor ends pointing upward. Electrodes are positioned on the right arm, the left arm, the right leg, and the left leg; the lead is sequentially repositioned for 6-second recording at locations V1-V6 on the chest.
- c. The machine is turned on, and the recording is begun.
- d. In nonautomatic machines, turn the lead selector to lead l and run it for 6 seconds for each lead from I through aVF. Then turn the lead selector to neutral and determine the proper placement for leads V1-V6 before recording. The position of V1 is at the fourth intercostal space, right sternal border. V2 is at the fourth intercostal space, left sternal border. V3 is midway between V2 and V4. V4 is at the left midclavicular line at the fifth intercostal space. V5 follows V4 in a straight line over the fifth intercostal space to the anterior axillary line, and V6 follows V5 in a straight line over the fifth intercostal space to the left midaxillary line.
- e. The procedure takes 15 minutes.
- f. During emergencies, three electrodes can be placed for monitoring: the white lead on the right upper chest, the black lead on the left upper chest, and the red lead on the lower left lateral chest.
- Simultaneous 12-channel recording:
- a. The client is positioned supine.
- b. The limb leads are connected to electrodes, and each is attached to a limb.
- c. Leads V1-V6 are connected to electrodes and attached to the chest wall in the locations described under procedure 1.
- d. The machine is activated, and a simultaneous recording of all 12 channels is printed automatically by the electrocardiograph machine.
- e. The procedure takes 5–10 minutes.
- Label the ECG with client's name, room number, date, time, and episodes of chest pain during the procedure.
- Remove the electrodes and cleanse the skin of any residual conductive gel.
Client and Family Teaching
- You should not move or talk during the procedure.
Factors That Affect Results
- Body movement, poor skin cleansing, or improper electrode placement produces an artifact, which may necessitate repeating the test.
- The results should be interpreted in comparison with prior electrocardiograms, if available.
- MI produces three changes on the ECG: elevated ST indicates formation of ischemia, and then the T wave flattens and becomes inverted with an enlarged Q wave appearing, which indicates necrosis.
- See also Holter monitor; Signal-averaged electrocardiography.
- The abbreviation “EKG” is often spoken and written instead of the more proper “ECG” to decrease confusion with “EEG” (electroencephalogram).