What is a Holter monitor?
It is a medical device that allows the continuous recording of cardiac activity (electrocardiogram) or also of blood pressure figures over a long period of time, usually 24 hours.
It consists of a recorder about the size of a smartphone and a cable with 12 electrodes that are attached to the chest just like when we do an electrocardiogram. This is in case you want to record cardiac activity.
When what you want to record is blood pressure, we will also have the recorder and instead of the electrodes we will put a portable sphygmomanometer (device that measures blood pressure figures) that takes measurements of blood pressure according to the programmed frequency (usually every 20-30 minutes). This blood pressure Holter is also called ABPM (ambulatory blood pressure monitor).
How is the study performed?
The patient must go to a specialized medical center that has a HOLTER and/or ABPM and medical personnel who are experts in their use, reading and interpretation (cardiologist, internist, etc.). In the case of an outpatient electrocardiogram, the adhesive tapes are placed on the chest just as when the study is done in the clinic and the cables that go to the recorder are attached under the clothing. If it is a sphygmomanometer, it is placed around one of the arms and is also hidden by the clothing; the recorder is usually placed with a belt that the device itself carries on the patient’s waist. Due to its reduced weight, the Holter or ABPM does not cause any discomfort.
Once the device is placed, the patient leaves the clinic and goes about his normal life. It is very important that he does his daily activities and does not stay sitting at home. In addition, the patient must make a record on a sheet of paper of the most notable activities carried out during the day (whether he or she has walked, climbed stairs, bedtime) in order to correlate the records with these activities.
In the case of cardiac activity recording, monitoring is continuous and no vibration or discomfort is perceived. If the recording is of blood pressure, the sphygmomanometer (cuff) inflates and deflates in a programmed manner and at the established frequency. When this happens, the patient must try to keep the arm still while the cuff inflates and deflates.
The duration of the study is usually 24 hours, after which the patient will return the device to his or her clinic so that a specialized doctor can proceed to read and interpret it.
Is the HOLTER bothersome?
The recorder is very light and, as for the blood pressure readings, the patient will only notice the first ones, the following ones going practically unnoticed as the patient gets used to it. It does not cause any discomfort when sleeping. When it comes to ECG, slight skin irritations may appear due to the gel adhesive on the stickers. This usually disappears when it is removed.
Sometimes a tingling or throbbing sensation may appear in the arm on which the cuff is placed when it is inflated, but this is usually temporary and without further problems.
Is there any risk?
Not at all, it is completely harmless. These studies do not pose any risks to the patient.
Are there any contraindications for having a HOLTER?
There are no contraindications for this test.
Why should I have a HOLTER or an ABPM?
The ECG holter is mainly used to study arrhythmias, bradycardia, coronary disease and extrasystoles.
- Analysis of the heart rhythm.
- ST segment analysis.
- Counting and classification of heart disease.
In the case of a 24-hour ABPM study of blood pressure, there are several cases in which it is recommended due to its proven usefulness:
- Diagnosis of arterial hypertension.
- Diagnosis of white-coat arterial hypertension.
- Control of arterial hypertension in patients under treatment for this disease.
- Identifying periods of the day in which the patient does not have their blood pressure under control.
- Assessing nocturnal blood pressure in snoring patients.
It should be noted that the HOLTER, by recording cardiac activity and/or measuring blood pressure for 24 hours, gives us a very good idea of these values of the patient at different times of the day with their different physical activities. The information it provides while we sleep is very useful, since this value is very important for the prognosis of patients and it is the only test that gives us these values.