A variety of treatments are available for patients with heart rhythm disorders. However, in many cases, nothing more than reassurance and/or lifestyle modifications are required to relieve the symptoms.
Abnormally fast heart rhythms (tachycardias) can be controlled with medication or cured with cautery (ablation). Abnormally slow heart rhythms (bradycardias) that lead to dizziness or fainting can be treated by the implantation of a pacemaker device. Pacemaker-like devices can also be used to improve the breathlessness associated with heart failure (cardiac resynchronization therapy) and/or protect against sudden cardiac death (implantable cardioverter defibrillators).
Some heart rhythm conditions can be controlled with medication, especially when the symptoms are very mild or short-lived. There are many medications available and further information can be found on the British Heart Foundation.
Conventional Ablation (Cautery)
The electrical short circuits, which are responsible for abnormally fast heart rhythm problems (supraventricular tachycardia/SVT), can usually be cauterized (ablated) away. This is now a routine procedure in the UK and is performed in all age groups from young children to the elderly. Approximately half of the procedures are performed using only a combination of local anaesthetic to numb the top of the leg and mild sedation. The amount of each can be tailored to ensure the patients are thoroughly pain-free and relaxed. A general anaesthetic is routine for more complex cases or at the patients’ specific request.
During a typical ablation, a number of tubes (sheaths) are inserted into the right femoral vein, which is found just beneath the skin crease in the right groin. Occasionally, both left and right femoral veins are used. Through these sheaths, long, flexible, platinum-tipped plastic wires (catheters) are passed painlessly up to the heart using X-ray imaging. Recordings of the electrical signals within the heart can then be made. Initiating an episode of abnormal heart rhythm is often required to confirm the diagnosis. Although this can be uncomfortable, it is perfectly safe. The abnormal connections are then burned or less commonly, frozen away. X-ray imaging is once again used to guide the ablation catheter within the heart. A period of testing then follows to ensure the procedure has been a success. Procedures can last anything between 1 and 3 hours. It is very uncommon for procedures to last any longer.
Some heart rhythm problems including atrial fibrillation (AF) are the result of many different ‘short circuits’ and require more extensive ablation. To minimize the use of X-ray imaging, advanced computer technology, not unlike satellite navigation systems, are used to create a 3D reconstruction of the heart. This enables the operator to guide the ablation catheter around the heart with pinpoint accuracy. A general anaesthetic is more commonly used for these procedures.
1. Ablation of the posterior wall during AF ablation »
The cornerstone of AF ablation is electrical isolation of the pulmonary veins that drain into the left atrium. This involves the ablation of rings around the pulmonary veins. The CARTO 3 system is used to generate a 3D ‘geometry’ (or model) of the patients left atrium. It allows the operator to view the catheters in 3D space as they move in the heart and reduces the use of x-rays during the case. Note the green tipped ablation catheter ablating on the back wall of the chamber. We use the new SMARTOUCH contact sensing catheter. The circular pulmonary vein catheter is in the left upper pulmonary vein and confirms when the vein has been successfully isolated.
Atrial fibrillation ablation is one of the most commonly performed procedures at the Bristol Heart Rhythm Centre. This condition is caused by abnormal ‘extra heart beats’ which spread into the heart from one of the four pulmonary veins connected to the left atrium.
2. Angiogram of the left atrium
Angiogram of the left atrium during which dye is injected to demonstrate the branching pulmonary veins arising from the main chamber. The dye then exits the atrium and enters the left ventricle which is seen below the atrium. It then pumps the dye into the main artery of the body (the aorta), that is seen leaving the heart.
Atrial fibrillation can be cured by creating protective rings around the origin of the pulmonary veins which prevent the abnormal ‘extra heart beats’ from escaping into heart.
3. CARTO3 geometry of the left atrium
A further CARTO3 map of the left atrium showing a completed set of ablation lesions that resulted in isolation of the pulmonary veins and prevented recurrence of atrial fibrillation.
4. NavX geometry of the left atrium
NavX is an alternative 3D mapping system to CARTO3. The red ablation lesions demonstrate the more extensive ablation that might be performed in a patient with persistent atrial fibrillation.
The majority of these devices can be implanted quickly and painlessly via a small incision under the left collarbone. A general anaesthetic can be provided at the patient’s request. X-ray imaging is used to guide the pacemaker leads through the veins, into the heart and then connected to the pacemaker device, which is implanted under the skin. Most implantation procedures take less than 2 hours and the patients can return home later the same day. A single stich will need to be removed one week later.