Procedures to treat cardiac arrhythmias

Cardiac arrhythmias can be treated with different operations and procedures. Depending on the cause of the arrhythmia, a pacemaker is implanted, an operation is performed on the atrial appendage, or an electrophysiological procedure is initiated.

Arrhythmias which affect the heart rate are called cardiac arrhythmias. These can originate in the atria or in the ventricles. Basically, a distinction is made between an overly fast heartbeat (tachycardia) and one which is too slow (bradycardia).  Heartbeats which occur between two normal heartbeats are called extrasystoles. They are mostly harmless, but also usually occur unnoticed in completely healthy patients. Sometimes those who are affected feel as though their heart has skipped a beat. Treatment is generally not required in most cases.

Cardiac arrhythmias which do require treatment are atrial flutter and atrial fibrillation, ventricular tachycardia, ventricular fibrillation and bradycardia.

Patients with atrial fibrillation have a far higher risk of suffering a stroke. The ciliary action of the atrium can cause blood clots to occur in the heart and then be carried to the cerebral vessels. With time, atrial fibrillation can also lead to cardiac insufficiency.

There are different procedures available to treat cardiac arrhythmias. They include cardiac pacemakers, electrophysiological procedures (defibrillation, cardioversion and catheter ablation) as well as surgical ablation and operations on the atrial appendage.

Catheter ablation

Catheter ablation is an electrophysiological procedure. In the process, the areas in question which are responsible for the abnormal heart activity are destroyed (ablated) using radiofrequency current (radiofrequency ablation). It is the treatment of choice for the majority of possible cardiac arrhythmias, above all for atrial flutter, atrial fibrillation, and ventricular tachycardia.

How is the procedure performed?

A cardiac catheter is inserted into the groin under local anaesthetic and pushed towards the heart. In the case of atrial flutter, access over the inguinal vein in the groin is usually sufficient. In the case of atrial fibrillation, access can usually be gained over an artery. The tips of the catheter are heated with radiofrequency current in the heart. In this way, the affected areas can be thermally destroyed and ablated. As a consequence, the tissue is isolated and can no longer prevent electrical conduction. Catheter ablation is a minimally invasive procedure and does not require an anaesthetic. Patients often sleep during the procedure due to the sedation. The procedure lasts one to three hours and the patients can usually leave the hospital one to two days later.

What is the success rate of this procedure?

Catheter ablation produces different results. The success rate is very good for patients with atrial flutter – 80 to 95%. It is lower for patients with atrial fibrillation (60 to 75%), and ablation often has to be performed several times to eliminate the disorder completely. In difficult cases, catheter ablation can be combined with surgical ablation. The success rate is between 50 and 80% in patients with ventricular tachycardia.

What are the possible complications and risks of this procedure?

The procedure is low-risk and serious complications rarely occur. After an operation, atrial fibrillation can take anywhere between a few days to weeks to fully disappear. Other arrhythmias such as atrial flutter or Wolf-Parkinson White syndrome are immediately remedied after the procedure. Blood thinning (anti-coagulation) treatment must be carried out as long as the atrial fibrillation exists.

Operation on the atrial appendage

When a patient has atrial fibrillation, blood clots occur primarily on the left atrial appendage. The atrial appendage is a cauliflower-like structure in the cardiac atrium. Removal of this structure or closure of the atrial appendage with an umbrella-like device is an alternative to treatment with blood-thinning medications. This procedure is used when no long-term blood thinning is possible due to an increased risk of haemorrhaging.

Surgical ablation

Surgical ablation is performed less often. During this technique, access is gained over small incisions in the chest (keyhole surgery). The affected sections are atrophied with heat in a similar manner to catheter ablation. Surgical ablation is often combined with an operation on the atrial appendage. The operation is performed under general anaesthetic and takes approx. two hours.

Surgical ablation is also used when other procedures such as bypass operations or heart valve operations are required at the same time.

It has a success rate of 80 – 90%.

Cardiac pacemakers

Pacemakers are small, electronic systems which monitor the heart rate. They take over when the heart beats too slowly (bradychardia) or too fast (ventricular tachycardia, ventricular fibrillation). The modern systems can intervene very subtly in the electrical cardiac activity and thus guarantee normal heart activity. A pacemaker sets the pace when the heart beats too slowly. A defibrillator is used when there is a risk of ventricular fibrillation. Analogous to the external defibrillator, the system provides a targeted electrical impulse in an emergency to prevent fatal ventricular fibrillation.

One specialised use for a cardiac pacemaker is in resynchronisation treatment, when a patient is suffering from cardiac insufficiency.  In some cases of cardiac insufficiency, there is not only a weakness of the heart muscle but also a disorder of the electrical heart muscle activity. As a result of this, the heart muscle does not contract completely synchronously, which causes a drop in the cardiac output. In this case, a pacemaker can be of assistance and resynchronise the heart muscle.

How is the procedure performed?

A cardiac pacemaker or a defibrillator is usually implanted under the skin under the collarbone; the patient is given a local anaesthetic for the procedure. The electrodes for monitoring and controlling cardiac activity are pushed into the respective cardiac atrium via a vein and affixed there. The operation takes around one hour. After monitoring the system and conducting further checks before discharge, a patient can usually be discharged after a night in hospital.

What is the success rate of this procedure?

Extremely good results are achieved with a pacemaker or implanted defibrillator. People who wear a pacemaker can lead an almost normal life.

What are the possible complications and risks of this procedure?

Cardiac pacemakers are normally well tolerated.

Use of the devices can cause vascular or nerve injuries. The implant does move on occasion, which affects how it functions. Pacemakers can cause further cardiac arrhythmias.

What happens after the operation?

The function of the implanted system must be regularly at intervals of six months to one year. If it requires adjustment, the cardiac pacemaker can be programmed externally. Depending on how it is used, the lithium battery lasts between six and ten years. After this time, the pacemaker must be replaced.  Magnetic fields and electrical installations can affect how it functions. Wearers of cardiac pacemakers are therefore fully informed of the possible risks.

Electroconversion

Electroconversion, or electrical cardioversion, is used to treat various cardiac arrhythmias. It is most commonly used for atrial fibrillation. Electroconversion involves the administration of a targeted external electric impulse to resolve atrial fibrillation and restore a normal heart rate, or sinus rhythm.

What preparations are carried out before the procedure?

Patients must fast for at least 6 hours prior to treatment. Anticoagulation treatment (blood-thinning) must also be started three to four weeks before the procedure to prevent blood clots from occurring. However, patients suffering from atrial fibrillation are often already taking a blood thinner, as the disease goes hand in hand with an increased risk of stroke.

How is the procedure performed?

The procedure is therefore performed in specialised hospitals and centres of expertise. Similar to defibrillation, two electrodes are placed on the chest and a short targeted electrical impulse is delivered. During treatment, the patient is under a brief anaesthesia (approx. 5 minutes) and does not feel the electrical impulse. An ultrasound of the heart is sometimes carried out prior to treatment.

What is the success rate of this procedure?

This procedure has a success rate of over 90%. In cases where treatment does not achieve the desired effect, there is no further negative impact on the atrial fibrillation. The treatment can be repeated if the atrial fibrillation reoccurs.

 

What are the possible complications and risks of this procedure?

Electrical cardioversion usually proceeds without any complications and holds no significant risk. The skin where the electrodes were placed may redden slightly. Some patients report a temporary feeling in the chest akin to muscle soreness. Other cardiac arrhythmias occur in rare cases, but these can also be resolved with electro treatment.

What happens after the operation?

Following treatment, patients are monitored for a further two to three hours, and checks of their heart rate and blood pressure are carried out. Due to the brief anaesthesia and the sedatives administered to them, patients should not drive or use machines the same day.

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