Ablation

Cardiac ablation is a surgical procedure designed to treat certain types of heart rhythm disorders known as arrhythmias. 

It restores a normal heart rhythm by isolating or destroying small areas in the heart that are causing abnormal electrical signals. This procedure can improve patients’ quality of life by reducing their symptoms and risks of long-term complications. 

How does ablation work?

Cardiac ablation is a minimally invasive procedure. This means that it does not require open-heart surgery. The procedure is performed percutaneously by inserting a thin, flexible tube called a catheter into a blood vessel, usually in the groin. The catheter is then guided through the vessel to the heart. 

During most ablations, a local anesthetic is injected into the area where the catheter will be inserted for the procedure. Additional pain-relieving and relaxing medications are also used as needed to ensure the patient’s comfort during the procedure. 

In the initial phase, the catheter allows the physician to create a map of the heart by detecting the electrical signals to precisely locate the arrhythmia’s source. The physician then uses the catheter to deliver energy to the tissues causing irregular heartbeats by creating small scars that block the transmission of abnormal electrical signals.

The ablation procedure lasts one to two hours on average, depending on the technique used. Most patients can return home the same day although some may stay at the hospital for a brief period for observation.

Three different energy sources can be used to destroy the tissues causing arrhythmia: radiofrequency, cryotherapy and electroporation. The energy source chosen by the surgeon is delivered via catheter to the areas causing the disorders. This process will create small scars that block the transmission of abnormal electrical signals.

Energy sources used in ablation

Three types of energy can be used to destroy the tissues causing arrhythmia: radiofrequency, cryotherapy and electroporation. The choice of energy source depends on the patient’s needs and the characteristics of their arrhythmia.

• Radiofrequency

Radiofrequency is the technique most commonly used for ablation, especially to treat atrial fibrillation. It uses heat to destroy the tissues causing abnormal electrical signals. The catheter is heated up to approximately 40°C to burn the targeted cells

• Cryotherapy

Cryotherapy is an alternative to radiofrequency with similar effectiveness. It uses extreme cold (-45°) to destroy the abnormal heart tissues. The catheter is equipped with an inflatable balloon that is positioned in the left atrium, at the entrance to the four pulmonary veins. The surgeon checks its position and ensures complete occlusion of the four pulmonary veins before using liquid nitrogen to cool the balloon to a temperature between -20° and -60° to freeze and destroy the abnormal cells. 

• Electroporation

Electroporation is a more recent technique that is particularly precise. Unlike radiofrequency and cryotherapy, which use heat to destroy the cells causing arrhythmia, electroporation uses high-voltage (2000 V) electric fields with extremely brief durations (lasting microseconds or nanoseconds). This approach can target only the cells responsible for the arrhythmia, without affecting the surrounding tissues. Thermal methods, like radiofrequency and cryotherapy may, in rare cases, pose a risk to organs located near the heart, such as the esophagus. In contrast, electroporation reduces this risk by avoiding the use of heat, making it safer for the surrounding tissues. In addition to improving safety, it is also faster, with an average treatment duration of approximately one hour. 

When is cardiac ablation considered?

Cardiac ablation is generally recommended in cases where medication is not sufficiently effective in controlling heart rhythm disorders. It is well-suited to several types of arrhythmias:

• Atrial/auricular fibrillation. This is the most common heart rhythm disorder. These rapid and irregular contractions of the atria increase the risk of stroke (cerebrovascular accident – CVA) and heart failure. 
• Atrial flutter, which has similar symptoms to those of atrial fibrillation, can also be treated with cardiac ablation. 
• Ventricular and supraventricular tachycardias, in which the heart beats too quickly, can cause palpitations, dizziness, and fainting. 
• Ventricular fibrillation is a rarer but potentially fatal condition that requires rapid intervention. 

How do I prepare for an ablation?

You will need to undergo several tests before the procedure to prepare for the ablation. The physician may prescribe:

• An electrocardiogram (ECG or EKG) to record the heart’s electrical activity;
• A cardiac echogram to view the heart’s structures and detect any abnormalities;
• Magnetic resonance imaging (MRI) to obtain a detailed image of the heart and identify the areas to be treated. 

What happens after an ablation?

In about 90% of cases, an ablation successfully resolves tachycardia issues. For atrial fibrillation, the success rate is around 80%, but it can increase by performing a second procedure if necessary. In most cases, patients experience a significant improvement in their quality of life: their symptoms decrease considerably or disappear, and they often require less medication, leading to fewer side effects.  

Peut-il y avoir des complications ?

As with any procedure, there are risks of complications, but they are rare. The main risks include: 

• Vascular complications, with the possibility of bleeding or infections in the area where the catheter was inserted;
• Cardiac complications caused by damage to healthy tissue, which may occasionally require emergency treatment or implantation of a pacemaker; 
• Pulmonary vein stenosis, a narrowing of the veins that can lead to shortness of breath;
•  The formation of blood clots, which can cause a stroke or pulmonary embolism. To reduce this risk, anticoagulants are administered before, during, and after the procedure.

In most cases, the ablation is performed without any serious complications and provides significant benefits for patients affected by arrhythmias.