Catheter ablation is a special form of cardiac catheter surgery that can also treat rapid cardiac arrhythmias using electricity.
Catheter ablation is already the standard therapy for some forms of cardiac arrhythmia (tachycardia). While medication merely suppresses the palpitations, catheter ablation can cure this condition.
The success rates are quite high and are, for example, for
- atrial flutter,
- AV node reentry tachycardia or
- WPW syndrome
well over 90 %.
The basis for subsequent catheter ablation is an electrophysiological examination of the heart and the conduction in the heart muscle. With the help of this examination, the doctor first determines where in the heart the arrhythmia begins. The cardiac arrhythmia can then be addressed using catheter ablation.
This requires a special cardiac catheter. The usual access point is in the groin. However, the doctor can also insert the cardiac catheter into the vein in the arm or neck.
In order to reach the left atrium, the doctor also punctures the septum (cardiac septum). For the puncture, the doctor pushes a long needle into the right atrium and pierces the septum at the thinnest point. The cardiac catheter can then be advanced through the opening in the septum.

Cardiac arrhythmias are very easy to recognize on an electrocardiogram (ECG) © Volker Werner / Fotolia
This can emit high-frequency current for a short time. The high-frequency current is used to "obliterate" the diseased area in the heart and thus stop the palpitations. In the case of so-called circling tachycardias, the circuit must be interrupted by one or more current emissions.
In all cases , the obliterated tissue gradually scars and becomes non-functional in terms of conduction.
After catheter ablation, the doctor attempts to trigger the tachycardia again in order to monitor the success of the operation. To do this, he uses direct stimulation through the cardiac catheter or certain medications that are administered intravenously.
The ablation is completed as soon as the arrhythmia can no longer be triggered.
After catheter ablation, the cardiac catheters are removed. The doctor closes the access points in the groin or crook of the arm with a pressure bandage.
The patient must then remain in bed for 6 to 24 hours to ensure that the access does not reopen. Otherwise, secondary bleeding may occur.

Different areas of the heart can be affected by arrhythmia © designua | AdobeStock
Cryo ablation
In cryo ablation, liquid gas is fed through a metal electrode to the tip of the cardiac catheter. This causes the metal electrode to freeze to the muscle tissue. In this way, the cardiac catheter cannot slip during ablation.
The temperatures of -80° C lead to cold obliteration of a few millimeters in diameter.
The application of cryo-ablation is painless.
AV node ablation
AV node ablation is also a frequently performed ablation method.
The AV node conducts atrial fibrillation only irregularly. This leads to significant arrhythmias in the ventricles. If the AV node is obliterated, the irregular transmission of signals from the atrium stops.
However, the AV node is the "pacemaker" of the heart. Without the AV node, a pacemaker must take over this function - this is the disadvantage of AV node ablation.
In future, the affected patient will be completely dependent on the pacemaker . Without its help, impulses would no longer be transmitted from the atria to the ventricles.
However, if the pacemaker fails, the patient does not have to die immediately. In this case, another natural pacemaker node within the ventricular muscles kicks in. This generates a replacement rhythm of around 20 to 40 beats per minute and keeps the ventricles "beating".
Ablation of the AV node and implantation of the pacemaker usually lead to a significant improvement in quality of life.
The biggest disadvantage of AV node ablation is that the pacemaker has to be replaced as soon as the batteries are exhausted. This means that several operations are necessary in the course of a patient's life.
Following the cardiac catheterization operation, a pressure bandage is applied and cardiac activity is monitored by
continuously documented. Patients usually leave the clinic after around 24 hours.
Nevertheless, the cardiac catheterization procedure involves some risks. The risk of complications is greatest in the case of severe heart disease. The insertion of the cardiac catheter can lead to minor vascular injuries, which could be quite dangerous in the area of the heart. Infections or blood clots that can cause a heart attack rarely occur.
Today, both atrial arrhythmias and ventricular tachycardias are treated with catheter ablation. The success rates are very much dependent on the general condition of the patient.
Catheter ablation is 90% successful in most people with vasoconstriction. In patients with pre-existing heart conditions, the chances of success drop to less than 50%.
Patients with ventricular tachycardia are often also implanted with a defibrillator (similar to a pacemaker).
The use of catheter ablation for atrial fibrillation is currently a booming branch of cardiac research.
In this form of tachycardia, ablation using radiofrequency current is not yet a recognized standard form of therapy. So far, catheter ablation has only been used when all other treatment options have been exhausted or the patient is suffering very severely.
In the case of atrial fibrillation, it is not possible to identify a clear point of origin. This makes treatment using cardiac catheterization all the more difficult. In most cases, many different sites have to be sclerosed in order to stop the atrial fibrillation.
Studies have now shown that atrial fibrillation is very often caused by disturbances in the four pulmonary veins. There, small tongues of heart muscle connect the heart muscle tissue of the left atrium with the veins. Sclerosing these myocardial tongues is one of the treatment strategies for atrial fibrillation.
Cardiologists also refer to this type of cardiac catheterization as "pulmonary vein isolation". Pulmonary vein isolation is only possible for patients suffering from paroxysmal atrial fibrillation.
The chances of success for this cardiac catheter operation are currently between 50 % and 70 %. Sometimes a second treatment is necessary, in other cases the atrial fibrillation cannot be stopped completely. However, after catheter ablation, patients respond better to antiarrhythmic medication, which had often previously been ineffective.
Ablation experts are usually cardiologists. A cardiologist specializes in the diagnosis and treatment of diseases of the cardiovascular system. After completing their medical studies, heart specialists have completed a specialist course in internal medicine and cardiology.
This specialist training to become a qualified cardiologist takes a total of 6 years.