Catheter ablation (cardiac ablation)

An overview of cardiac arrhythmias

Cardiac arrhythmias are deviations from the normal heartbeat and can lead to a pulse that is too fast (tachycardia), too slow (bradycardia) or irregular (arrhythmia). They can occur when the electrical impulses in the heart are faulty. Atrial fibrillation, for example, is caused by overactive electrical impulses in the pulmonary veins of the left atrium. These ‘faulty spark plugs’ send out pulse-like signals that disrupt the regular heart rhythm and cause typical fibrillation.

Cardiac arrhythmias are often accompanied by symptoms such as tachycardia, palpitations, dizziness or shortness of breath and can have various causes, including heart diseases such as angina pectoris, heart attacks, heart valve defects, heart failure  or inflammation of the heart muscle. Hyperthyroidism, the use of drugs or certain medications can also trigger cardiac arrhythmias.

Treatment options for cardiac arrhythmias vary depending on the type and severity of the illness and include medication therapies,  pacemakers, closure of the heart auricle, electrocardioversion and catheter ablation. For many cardiac arrhythmias, in particular for atrial flutter, atrial fibrillation and ventricular tachycardia, catheter ablation is considered the first choice of treatment to restore the heart rhythm to normal.

Treatment goal

The primary goal of a cardiac ablation is the permanent restoration of a regular heartbeat. A stable sinus rhythm is critical to maintaining normal heart function and ensuring that the heart muscle can efficiently pump blood through the body. By destroying the specific tissues responsible for the electrical malfunctions, ablation interrupts the abnormal impulses and prevents them from disrupting the heartbeat.

In addition to rhythm normalisation, ablation contributes significantly to alleviating the symptoms of cardiac arrhythmias such as palpitations, dizziness and discomfort. Ablation also reduces the risk of serious complications such as heart failure, which can result from  sustained heart overload as a result of arrhythmias. Ablation also reduces the risk of strokes, as atrial fibrillation in particular encourages the formation of blood clots, which can then enter the bloodstream and block important vessels.

If catheter ablation does not promise the desired treatment success or if additional heart surgery, such as bypass or heart valve surgery, is required, surgical ablation can be performed.

Catheter ablation procedure

Catheter ablation is a minimally invasive procedure and is performed under local anaesthetic. A thin heart catheter is inserted through the femoral vein or, in the case of certain cardiac arrhythmias such as atrial fibrillation, through an artery and pushed into the heart. The catheter tip is then deliberately heated (radio frequency) or redirected (cryoablation) with the aid of high-frequency current, whereby the diseased tissue areas are thermally destroyed. This isolates the tissue so that it can no longer interfere with the electrical conduction. The catheter is then carefully retracted and the injection site in the groin is closed with a compression bandage.

Patients usually sleep during the intervention due to the mild sedation. The surgery takes about one to three hours, and often patients can leave the hospital after one to two days.

Preparation and precautions

A thorough cardiological examination is performed prior to catheter ablation to determine the individual risk factors and ensure the patient is fit for the procedure. The patient receives comprehensive medical advice and is informed of any risks and the ablation’s prospects of success.

After consultation with the attending doctor, blood-thinning medications must be stopped in advance of treatment to prevent bleeding during the procedure. In addition, no solid food should be consumed at least six hours before the intervention and no water or clear fluids should be consumed two hours before the procedure.

Recovery and aftercare

After cardiac ablation, the patient usually stays in hospital for one or two days for observation. In the subsequent recovery phase, resting and avoiding stress are important in order to support the healing process and reduce the risk of renewed arrhythmias. Regular check-ups to monitor heart rhythm and general cardiac health are also part of the follow-up care.

After the intervention, it can take a few days to weeks for atrial fibrillation to disappear completely. On the other hand, other cardiac arrhythmias such as atrial flutter or Wolff-Parkinson-White syndrome are usually corrected immediately. Blood thinning (anticoagulation) is continued as long as the atrial fibrillation persists.

Prospects of success for catheter ablation

The catheter ablation’s chances of success vary depending on the type of cardiac arrhythmia. With atrial flutter, the success rate is very high at 80 % to 95 %. On the other hand, for atrial fibrillationit is slightly lower, around 60 % to 75 %, and several ablations are often required to completely eliminate the arrhythmia. In particularly persistent cases, a combination of catheter ablation and surgical ablation may be appropriate. The chances of success for ventricular tachycardia are between 50 % and 80 %.

Potential complications

Cardiac ablation is a low-risk procedure and the risk of serious complications is small. Nevertheless, as with any surgical procedure, there are certain risks associated with catheter ablation. The most common complications include bleeding at the injection site, myocarditis, infections or the appearance of new types of arrhythmias. In rare cases, serious complications such as a pericardial effusion or a stroke can occur.