VERIFIED CONTENTAuthor: lek. Katarzyna Banaszczyk

Atrial fibrillation is one of the three most common cardiac arrhythmias patients report to their physicians. For this reason, the treatment of this disease is constantly developing and new methods of therapy are used. What is atrial fibrillation and what is cryoablation used to treat it?

Atrial fibrillationtoarrhythmia , i.e.disturbance of the heart rhythm . In the case of atrial fibrillation, we are dealing with supraventricular arrhythmia, and more specifically with the atria of the heart.

The atria contract in an uncoordinated manner, which makes their work inefficient, and this arrhythmia is also accompanied by irregular (colloquially speaking "uneven") work of the ventricles. The atria of the heart may contract at a rate of 350-700 times per minute, but still their work is not efficient.

Causes of atrial fibrillation

This arrhythmia is mainly predisposed by arterial hypertension and heart diseases, such as:

  • ischemic heart disease,
  • heart valve defects,
  • heart failure,
  • cardiomyopathies,
  • congenital heart defects,
  • myocarditis and pericarditis,
  • heart surgery,
  • heart cancer.

It is important to be aware that other disorders in the body, not necessarily related to the heart and cardiovascular system, may also contribute to the occurrence of atrial fibrillation. Such states include mainly:

  • hyperthyroidism, but also hypothyroidism (less often),
  • severe infections in the body, sepsis,
  • obesity, diabetes,
  • metabolic syndrome,
  • chronic kidney disease,
  • practicing endurance sports, especially in the event of very intense training,
  • lung conditions such as chronic obstructive pulmonary disease (COPD).

Atrial fibrillation - symptoms

Before we discuss cryoablation, it is worth getting acquainted with the symptoms presented by patients with atrial fibrillation. These symptoms include, first of all:

  • feeling of palpitations,
  • heavy sweating,
  • weakness,fatigue,
  • deterioration of exercise tolerance,
  • fainting as well as dizziness.

Be aware that atrial fibrillation is often completely asymptomatic, therefore, for patients over the age of 65, it is advisable to have a heart rate test at least once a year to screen for atrial fibrillation.

Cryoablation - what is this method of treating atrial fibrillation?

Cryoablation is nothing more than applying low temperature to the piece of tissue that generates abnormal conduction of impulses in the heart muscle. In atrial fibrillation, abnormal electrical impulses come primarily from the pulmonary veins.

Destroying a piece of tissue that sends abnormal stimuli allows you to organize the work of the heart and regulate the rhythm of the atria and ventricles. Depending on the procedures, a temperature of -35 to -60 degrees Celsius is used.

Cryoablation - types

Treatment of atrial fibrillation with the use of low temperatures is not a uniform procedure. There are two types of cryoablation, more precisely:

  • point cryoablation - a much smaller area is cooled than during balloon cryoablation, this type of cryoablation is used when the place generating abnormal impulses is close to other important areas of the cardiovascular system,
  • balloon cryoablation - in this case, low temperature destroys a larger area and allows to isolate arrhythmogenic foci, the effectiveness of treatment of atrial fibrillation with this type of procedure is up to 80%.

Cryoablation - the course of the treatment

This procedure does not require thoracotomy, i.e. opening the chest. A special catheter, usually equipped with a balloon, is inserted into the body through the use of a venous vessel - typically a femoral vein, which is located in the groin.

This catheter reaches the place where the area responsible for generating arrhythmias is to be destroyed through the venous vessels. A substance is introduced into this catheter to freeze the area in question - typically nitrous oxide. This substance significantly cools the end of the catheter introduced into the body, thanks to which the entire procedure is very precise and there is no undesirable tissue damage.

By delivering cold to selected tissues, it is possible to destroy the cells that generate abnormal stimulation and thus to cure arrhythmia.

Importantly, the entire procedure is controlled by a doctor and he or she has the possibility to cool the area at the beginninga way to make this procedure reversible - that is, it puts the tissue in question into hibernation and can check if it has cooled down to stop the arrhythmia.

Cryoablation is performed in sterile conditions, the groin area, i.e. the place where the catheter is to be inserted, is thoroughly disinfected. What's more, it is worth mentioning that the patient is connected to devices monitoring vital signs throughout the procedure, including blood pressure and heart rate.

The catheter inserted into the femoral vein is constantly observed and monitored thanks to the use of X-ray imaging (X-ray).

Cryoablation - contraindications

Not every patient is allowed to perform the medical procedure described in this article. The most important contraindications to the cryoablation procedure are:

  • presence of embolic material in the atrium (in order to exclude the presence of such a condition, an imaging test - or more precisely, a transesophageal echo of the heart is performed before the procedure),
  • status after a recent ischemic stroke,
  • decompensated heart failure,
  • status after a recent myocardial infarction,
  • allergy to contrast agents used during imaging during the procedure.

Final qualification for cryoablation in atrial fibrillation depends on the patient's condition and comorbidities and is made by the physician together with the patient.

Cryoablation - does this treatment immediately eliminate arrhythmia?

You should be aware that the full therapeutic effect of the cryoablation treatment is only visible after about three months. This is due to the healing of cryoablated tissues and the formation of scar tissue at the site of the impact of the cold. Arrhythmia, i.e. atrial fibrillation, may recur over a period of up to three months, and this does not always mean that the procedure was performed incorrectly or that it turned out to be ineffective.

The final decision on the treatment of atrial fibrillation is made by the cardiologist after reviewing the patient's medical history. If you experience the symptoms described in this article, which may suggest this disturbance of the heart rhythm - you should urgently contact your doctor, because atrial fibrillation is a serious condition that can cause serious complications.

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