KUSH TRIPATHI

The Holter monitor


The Holter monitor records the heart's electrical activity through electrodes placed on the chest. The electrical impulses are then transmitted to an amplifier, which records them on a small magnetic tape or digital recorder for later review by a physician. This test provides the doctor with important information about patient's heart and its rhythm and can help identify the cause of such symptoms as chest pain, palpitations or dizziness.



The Working of Holter monitor

An ambulatory electrocardiogram is a portable recording of the heart rhythm taken during patient's normal activities. It is entirely painless and none of the equipment enters his/her body. It monitors his/her heart's electrical activity as detected on the surface of the skin, transmits this signal to an amplifier, and saves a record of the electrocardiogram on a small magnetic tape or digital recorder for subsequent review and analysis. Following completion of the monitoring period, the tape is scanned by a technician.



Ambulatory electrocardiograph has been available since the early 1950s, when Dr. Holter introduced his portable electrocardiogram to the medical community. Since that time, these devices have decreased in size and weight, but have increased in sophistication.


(DR. NORMAN J.HOLTER)

The first devices had to be worn in a backpack, and despite their large size and weight, could only review the heart along one axis (one direction).


(CASSETTE HOLTER RECORDER)

Modern devices can look at the heart along several different axes, and their weight and size are such that they do not interfere with your normal activities.


(MODERN FLASH CARD HOLTER RECORDER)

Information obtained by the Holter monitor

When applied to the patient's chest, the Holter monitor can identify any abnormal heart rhythms or rate. It picks up skipped heartbeats, as well as those that are excessively fast or slow. Under some circumstances, the test can identify whether the heart has a sufficient supply of blood and so help your physician determine if there are blockages or constrictions in the coronary arteries (the blood vessels that supply blood to the heart). Thus, if patient has had chest pain, or episodes of fainting or dizziness, this test will show what happens to his/her heart while he/she has these symptoms. If patient is taking medication for a heart condition, the test helps evaluate how well it is working. If he/she is using a temporary or permanent pacemaker (a device that helps to regulate the heart rhythm), the Holter monitor can detect whether it is working properly.



How the test is done

First, the technician shaves the hair off the areas where the electrodes (sticky patches that detect the heart's electrical signals) are to be placed. After shaving, the skin is cleaned with a fat degreaser to remove any oil from the skin so the electrodes will have better contact and not fall off during the test. Next, an antiperspirant is wiped over the shaved area to prevent perspiration from loosening the electrodes. Finally, the electrodes are applied to patient's chest.



The number of wires and electrodes applied depends upon the number of "leads" (the angle from which the heart is viewed), the physician feels should be monitored. Often this may require as many as five or six electrode patches with their accompanying wires. Each electrode and wire unit is placed in a specific place on the chest. It is important that the electrodes remain stable once attached. After they are securely fixed to patient chest, the excess wire is taped to the skin to prevent their accidental disconnection. Next, the technician checks the system to be sure that it is working properly. The monitor is connected to an electrocardiogram recorder to determine if the ambulatory electrocardiogram provides a high quality tracing free of excessive "noise" or electrical interference. The patient may be asked to move around, to sit, stand, lie down, bend, and breathe deeply, to provide a baseline reading of the heartbeat and to assure that simple movement does not interfere with the recording.

The cassette tape or digital recorder is then tested and a battery inserted into the device. The patient can wear the tape recorder either on your belt or over his/her shoulder, depending on the model used.


The diary card

The last and most important part of the test is the diary card, the patient will be asked to fill out. On this card the patient record his/her activities and symptoms during the day of monitoring. This is an extremely important part of the test since it enables the technician to correlate patient's heart electrical activity with his/her symptoms and activities. If the patient do not write anything in the diary, it may be impossible for doctor to determine the cause of any abnormalities and the test may have to be repeated. The information needed on the diary card includes the day, time, type of activity performed (running, walking, grocery shopping, etc.), and any symptoms you experience. Be certain to fill the diary out correctly and carefully. The test generally lasts from 24 to 48 hours, depending on the period of time specified by doctor.

Follow-up



After completion of the test, the patient will be asked to return to the laboratory for removal of the device. At this point, only half the test is completed. The last half of the test consists of an analysis by a technician of the 24-48 hours of tracings via a rapid scanning device.



Subsequently, the technician records any abnormal segments of the tracing, or those during which patient recorded symptoms in his/her diary. The technician's report and the pertinent printouts of the electrocardiogram are then sent to the physician.