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1. Any of various devices that record data from sensors monitoring the performance of a transportation conveyance over a period of time, used chiefly to analyze the causes of accidents, especially:
a. A crashworthy, water-resistant, and fire-resistant device that records data about a train, such as speed and brake use.
b. A flight recorder. Also called black box.
2. A medical device that detects and records cardiac abnormalities, such as changes in heart rate or rhythm, over a period of time. Also called event monitor.
3. A laser event recorder.
A portable heart rhythm monitor worn by a patient who suffers intermittent palpitations or loss of consciousness of unclear cause. The device transmits the patient's heart rhythms by telephone to a central laboratory, where symptomatic and asymptomatic dysrhythmias (such as atrial fibrillation and atrioventricular nodal re-entrant tachycardias) or heart blocks can be detected.
A small machine, worn by a patient usually for several days or weeks, that is activated by the patient to record his or her EKG when a symptom is detected.
Mentioned in: Electrophysiology Study of the Heart
Synonym/acronym: Ambulatory electrocardiography, ambulatory monitoring, event recorder, Holter electrocardiography.
To evaluate cardiac symptoms associated with activity to assist with diagnosis of arrhythmias and cardiomegaly.
Area of applicationHeart.
The Holter monitor records electrical cardiac activity on a continuous basis for 24 to 72 hr. This noninvasive study includes the use of a portable device worn around the waist or over the shoulder that records cardiac electrical impulses on a magnetic tape. The recorder has a clock that allows accurate time markings on the tape and the patient is asked to keep a log or diary of daily activities and record any occurrence of cardiac symptoms. When the patient pushes a button indicating that symptoms (e.g., pain, palpitations, dyspnea, syncope) have occurred, an event marker is placed on the tape for later comparison with the cardiac activity recordings and the daily activity log. Some recorders allow the data to be transferred to the physician’s office by telephone, where the tape is interpreted by a computer to detect any significantly abnormal variations in the recorded waveform patterns.
This procedure is contraindicated for
- Detect arrhythmias that occur during normal daily activities and correlate them with symptoms experienced by the patient
- Evaluate activity intolerance related to oxygen supply and demand imbalance
- Evaluate chest pain, dizziness, syncope, and palpitations
- Evaluate the effectiveness of antiarrhythmic medications for dosage adjustment, if needed
- Evaluate pacemaker function
- Monitor for ischemia and arrhythmias after myocardial infarction or cardiac surgery before changing rehabilitation and other therapy regimens
- Normal sinus rhythm
Abnormal findings related to
- Arrhythmias such as premature ventricular contractions, bradyarrhythmias, tachyarrhythmias, conduction defects, and bradycardia
- Hypoxic or ischemic changes
- Mitral valve abnormality
Factors that may impair the results of the examination
- Improper placement of the electrodes or movement of the electrodes.
- Failure of the patient to maintain a daily log of symptoms or to push the button to produce a mark on the strip when experiencing a symptom.
Nursing Implications and Procedure
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this procedure can assist in evaluating the heart’s response to exercise or medication.
- Obtain a history of the patient’s complaints or symptoms, including a list of known allergens, especially allergies or sensitivities to latex.
- Obtain a history of the patient’s cardiovascular system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
- Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
- Review the procedure with the patient. Inform the patient that it may be necessary to remove hair from the site before the procedure. Address concerns about pain related to the procedure and explain that no electricity is delivered to the body during this procedure and no discomfort is experienced during monitoring. Inform the patient that the electrocardiography (ECG) recorder is worn for 24 to 48 hr, at which time the patient is to return to the laboratory with an activity log to have the monitor and strip removed for interpretation.
- Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
- Instruct the patient to wear loose-fitting clothing over the electrodes and not to disturb or disconnect the electrodes or wires.
- Advise the patient to avoid contact with electrical devices that can affect the strip tracings (e.g., shavers, toothbrush, massager, blanket) and to avoid showers and tub bathing.
- Instruct the patient to perform normal activities, such as walking, sleeping, climbing stairs, sexual activity, bowel or urinary elimination, cigarette smoking, emotional upsets, and medications, and to record them in an activity log.
- Instruct the patient regarding recording and pressing the button upon experiencing pain or discomfort.
- Advise the patient to report a light signal on the monitor, which indicates equipment malfunction or that an electrode has come off.
- Note that there are no food, fluid, or medication restrictions unless by medical direction.
- Potential complications: N/A
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
- Instruct the patient to void prior to the procedure and to change into the gown, robe, and foot coverings provided.
- Instruct the patient to cooperate fully and to follow directions.
- Place the patient in a supine position.
- Expose the chest. Prepare the skin surface with alcohol and remove excess hair. Use clippers to remove hair from the site if appropriate; cleanse thoroughly with alcohol and rub until red in color.
- Apply electropaste to the skin sites to provide conduction between the skin and electrodes, or apply prelubricated disposable disk electrodes.
- Apply two electrodes (negative electrodes) on the manubrium, one in the V1 position (fourth intercostal space at the border of the right sternum), and one at the V5 position (level of the fifth intercostal space at the midclavicular line, horizontally and at the left axillary line). A ground electrode is also placed and secured to the skin of the chest or abdomen.
- After checking to ensure that the electrodes are secure, attach the electrode cable to the monitor and the lead wires to the electrodes.
- Check the monitor for paper supply and battery, insert the tape, and turn on the recorder. Tape all wires to the chest, and place the belt or shoulder strap in the proper position.
- After the patient has worn the monitor for the required 24 to 48 hr, gently remove the tape and other items securing the electrodes to him or her.
- Compare the activity log and tape recording for changes during the monitoring period.
- Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
- Advise the patient to immediately report symptoms such as fast heart rate or difficulty breathing.
- Recognize anxiety related to test results, and be supportive of perceived loss of independence and fear of shortened life expectancy. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Educate the patient regarding access to counseling services.
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
- Depending on the results of this procedure, additional testing may be needed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
- Related tests include antiarrhythmic drugs, blood pool imaging, calcium, chest x-ray, echocardiography, echocardiography transesophageal, electrocardiogram, exercise stress test, magnesium, myocardial perfusion heart scan, PET heart, and potassium.
- Refer to the Cardiovascular System table at the end of the book for related tests by body system.