Generality
The cardiac holter is a type of electrocardiogram that allows constant monitoring of the rhythm and electrical activity of the heart, over a period of time of canonical duration of 24-48 hours.
The exam - also known as ECG Holter or dynamic electrocardiogram according to Holter - uses a special battery-powered instrument, called a portable electrocardiograph.
If necessary, the survey also allows to evaluate the efficacy of a pharmacological treatment, undertaken for a certain heart disorder, or the functioning of devices (pacemakers, cardioverter defibrillator, etc.) previously implanted in the heart of the examined patient.
The installation of the portable electrocardiograph is a fast and painless procedure, which involves the application on the chest of some metal plates, called electrodes.
What is the ECG?
Short summary of what the basic electrocardiogram is
The basic electrocardiogram, or basic ECG or resting ECG, is an instrumental diagnostic test, which records and reports graphically, on a sheet of graph paper, the rhythm and electrical activity of the heart .
The basic electrocardiogram instrument, having the dual function of recording and graphically constructing cardiac function, is a computerized device known as an electrocardiograph .
Key elements for the correct functioning of the electrocardiograph are the electrodes, which are real recorders of the rhythm and electrical activity of the heart.
A typical basic electrocardiogram lasts a few minutes.
The doctor who usually has the interpretation of the graph resulting from a basic ECG is a cardiologist, that is a doctor specialized in cardiology.
What is cardiac holter?
The cardiac Holter is a special type of electrocardiogram which, thanks to the use of a battery-powered portable electrocardiograph, allows you to monitor the heart function - therefore rhythm and electrical activity of the heart - over a certain period of time, usually 24 -48 hours .
OTHER NAMES OF THE CARDIAC HOLTER
Cardiologists can refer to cardiac Holter in various ways, all equally correct, including: ECG Holter, electrocardiogram according to Holter and dynamic electrocardiogram according to Holter.
uses
The idea of creating a portable electrocardiograph, which registers the cardiac function for a certain number of consecutive hours, arises from the need to identify those alterations of the electrical conduction of the discontinuous heart, with sporadic appearance, which a basic ECG struggles to highlight (of usually due to timing problems).
That said, the cardiac Holter is an ideal diagnostic tool for cardiac arrhythmias, which have the peculiarity of "coming and going".
Brief review of cardiac arrhythmias
A cardiac arrhythmia is an alteration of the normal heart rhythm ( sinus rhythm ).
The normal heart rhythm of an adult human being has a resting contraction frequency of between 60 and 100 beats per minute.
In the presence of an arrhythmia, this frequency can vary decisively, making the heart rate faster, slower, irregular and / or at variable intensity.
There are many different types of arrhythmias. Among the most widespread and known types, include: sinus tachycardia, sinus bradycardia, atrial fibrillation, atrial flutter and ventricular fibrillation.
OTHER USES
In addition to the detection of cardiac arrhythmias, cardiologists resort to performing a cardiac holter in order to evaluate:
- The functioning of an implantable cardioverter pacemaker or defibrillator in subjects who are obviously carriers of it.
- The effects of a drug treatment for the resolution of a heart problem.
Preparation
As far as the preparation phase is concerned, the cardiac Holter provides some simple instructions, which the doctor usually communicates on the day of the diagnostic procedure.
The first important instruction is to avoid accidental or voluntary removal of the portable electrocardiograph during the entire duration of the exam. This involves the prohibition of practicing activities such as washing.
The second important instruction is to keep a diary, in which to report the moments of the day and the activities that have induced any episodes of palpitation, chest pain, dyspnea and / or vertigo (NB: these are the most common symptoms that people experience with a alteration of the electrical conduction of the heart). Thanks to the diary, cardiologists are able to make a more precise final diagnosis.
The third important education is to lead a normal life, dedicating oneself without worry to normal everyday activities. In fact, any changes could distort the results of the exam.
The fourth and last important instruction is a precautionary measure, which says to keep away from metal detectors, microwave ovens, electric blankets, electric razors, electric toothbrushes, cellular phones, computers etc., for the duration of the exam. This is a precaution without a proven scientific foundation, as no study has so far demonstrated unequivocally that the aforementioned everyday objects and instruments interfere with the proper functioning of the cardiac Holter.
Procedure
Generally the responsibility of a cardiologist doctor's assistant, the installation of the portable electrocardiograph is a simple, fast and painless procedure, which involves the application of a series of electrodes (the recording elements) in various points of the chest.
The electrodes for a cardiac Holter (and in general for any type of electrocardiogram) are metal plates, located at the ends of cables that connect them to the portable electrocardiograph. To ensure a good seal of the electrodes on the skin can be adhesive plasters, which surround the metal plates, or a sticky gel.
Once the electrodes have been applied, the cardiologist's assistant provides the patient with a comfortable shoulder bag in which to store the portable electrocardiograph.
From a strictly procedural point of view, the cardiac Holter can be divided into two consecutive phases:
- The recording phase of the rhythm and electrical activity of the heart . It is the first of the two phases and goes from when the cardiologist assistant installs and operates the portable electrocardiograph to when the same assistant or a colleague removes it.
In this phase, the instrument records and saves the cardiac function of the patient in an internal memory.
- The graphic translation phase of what was recorded in the previous phase . It is the phase that leads to obtaining, on a sheet of graph paper, the so-called electrocardiographic trace. A generic electrocardiographic trace has some characteristic features, which are repeated at more or less regular intervals and which are called waves .
The appearance of the waves and the distance between them are the elements of the path that allow cardiologists to interpret the state of health of the heart under examination.
For the graphic translation phase, a computerized device is needed, able to extrapolate the recording data present in the portable electrocardiograph.
During the recording phase, the patient must be careful not to bump or move the device excessively and not to disconnect the electrodes.
Curiosity: if the patient under examination is a man with a chest that is particularly rich in hair, the assistant of the cardiologist will shave the aforementioned anatomical area, to avoid the risk of premature detachment of the electrodes.
LONG-TERM CARDIAC HOLTER
Modern portable electrocardiographs have batteries that last up to a week.
Sometimes, in special cases, cardiologists take advantage of this long-lasting ability and monitor a patient's heart function for more than 48 hours, up to 7 days.
WHAT TO DO WHY EVERYTHING WORKS FOR THE BEST
Below is a summary of everything that guarantees the good outcome of the cardiac Holter:
- Avoid wetting the electrocardiograph and / or the electrodes. In general, medical personnel recommend taking a shower just before going to the hospital where the measuring instrument will be installed.
- Before the test do not apply any type of skin lotion or cream to the chest skin.
- During the procedure, avoid all those activities that could damage the electrocardiograph or induce the detachment of the electrodes. Therefore, doctors advise against sports activities and particularly busy work activities.
- Avoid close contact with objects that emit magnetic or electric fields.
In the same way avoid the frequentation of places characterized by magnetic fields or electric fields.
risks
Cardiac Holter is a safe and non-invasive procedure, the main drawback of which is the possibility that the removal of the electrodes will cause redness and swelling of the skin (obviously in the area of application).
Important note : the electrodes used for recording the rhythm and electrical activity of the heart do not emit electricity, therefore the patient is not at risk of receiving electrical discharges.
Results
Usually available within a few days, the results of a cardiac Holter are the result of the cardiologist's interpretation of the characteristic waves of the electrocardiographic tracing.
Cardiac Holter is a tool that satisfactorily captures any heart rhythm disorder when it occurs during the exam.
Depending on the type of disorder identified with the cardiac Holter, the cardiologist determines the next step: whether to resort to other diagnostic tests or whether to start a specific treatment.
PROBLEMS AND SOLUTIONS
In some cases, what emerges from a cardiac Holter is not sufficient to make a correct diagnosis of a heart disorder.
In fact, if in the 24-48 hours of the diagnostic procedure, the patient's heart does not show the alterations suspected on the basis of the physical examination and the history, the electrocardiographic trace is free of significant anomalies.
In such situations, the solution generally consists in repeating the exam with a longer duration (more than 48 hours) or in repeating it after a few weeks.
In all those cases in which, during the diagnostic procedure, the patient suffers from a cardiac rhythm disorder, the portable electrocardiograph captures this disorder and reports it on the track.
CARDIAC HOLTER, PACEMAKER AND DRUGS FOR HEART DISORDERS
In evaluating the functioning of a pacemaker or implantable cardioverter defibrillator, the cardiac Holter shows whether the aforementioned electronic devices, used for normalization of cardiac rhythm, are working well or not.
Similarly, in the evaluation of a drug treatment for a cardiac disorder, the cardiac Holter shows whether the drug in use is effective or requires a change in doses.
