SVT Ablation
What is an SVT ablation?
When to see a cardiologist
The SVT ablation procedure
Recovering from an SVT ablation
Complications of an SVT ablation
What is an SVT Ablation?
Supraventricular tachycardia (SVT) is an abnormal racing heart rhythm that can cause attacks of palpitations, dizziness, breathlessness and chest pain. The problem is usually caused by an extra electrical connection in the heart. You can read more about SVT here.
Patients with SVT are usually offered three options for treatment: to take a medicine when needed to terminate attacks, or to take a medicine every day to prevent or reduce attacks, or to have a procedure aiming to cure the problem entirely.
SVT ablation is a procedure undertaken to cure SVTs. Most SVT ablations start with an electrophysiological study to diagnose the precise cause of the SVT. The ablation stage of the procedure involves using a wire fed to the heart from the top of the leg to deliver electrical energy, heating a small amount of heart tissue and grazing off the abnormal tissue responsible for the SVT. In 90-95% of cases this prevents the SVT from occurring again with a single procedure. Multiple procedures using different technologies and approaches are needed in a small minority of patients.
It is uncommon to find an SVT that cannot be ablated with the right approach.
When to See a Cardiologist
Symptoms such as palpitations, a racing heart beat, episodes of sudden breathlessness, and chest tightness unrelated to exertion may be suggestive of an intermittent heart rhythm problem. Many of these can be diagnosed with the aid of an EP study and cured using an ablation.
The SVT Ablation Procedure
Most SVT ablations are carried out under local anaesthetic. The patient is awake but may receive sedative medications to make the procedure more pleasant. If a procedure is anticipated to be longer than usual, the ablation is sometimes offered under general anaesthetic.
Access is gained to one or more veins at the top of the leg and this is used to feed wires up to the heart to conduct an EP study and, once a diagnosis is made, to proceed to ablation. Local anaesthetic is used at the top of the leg and sedation is given throughout most of these procedures.
The EP study phase may be very quick, if a diagnosis is already known, or may last up to an hour. The ablation phase of the procedure involves applications of electrical energy to the internal surface of the heart followed by re-testing to see if the problem has been cured or not. The whole procedure may last up to two hours, sometimes more.
Recovering From an SVT Ablation
Recovery from an SVT ablation is generally very quick. The only real concern is bleeding from the puncture wounds used to access the vein at the top of the leg(s). For this reason patients are generally advised against running, swimming, and heavy lifting for a week or so after the procedure.
The DVLA stipulate a driving ban after all EP procedures. The length of the ban depends on the licence held. For example, group 1 (car and motorbike) drivers are currently subject to a two day ban.
Complications of an SVT Ablation
SVT ablation is a generally safe procedure. Around one in 100 patients will experience significant problems from the puncture wounds at the top of the leg and in extreme cases this may need surgery though the rate of this is much lower (around one in 1000). Some pain following the procedure, in the chest or around the puncture site in the leg, is common but usually mild.
Bleeding around the heart is also possible. Around one in 200 patients will need a pacemaker after an SVT ablation and one in 500 will suffer a stroke. The individualised risks of these complications may be higher or lower depending on the precise nature of the SVT being treated and other patient factors. Part of the consent process for any medical procedure involves being told your doctor’s assessment of the likelihood of complications, and how this balances against the benefits of the procedure.