Catheter ablation

What is catheter ablation?

Catheter ablation is a minimally invasive procedure that treats abnormal heart rhythms (arrhythmias) at their source. Fine, flexible tubes called catheters are passed to the heart, usually from a vein at the top of the leg, where they map the heart's electrical activity and identify the tissue responsible for the abnormal rhythm. That tissue is then neutralised with carefully targeted energy, either heat (radiofrequency), freezing (cryoablation) or, most recently, pulsed-field ablation, creating tiny areas of scar that block the faulty circuits.

For many arrhythmias, ablation offers something medication cannot: a realistic prospect of cure rather than lifelong symptom control.

Rhythm problems ablation can treat

Atrial fibrillation (AF) ablation

Atrial fibrillation is the most common sustained rhythm disorder, and ablation, principally pulmonary vein isolation, is now a first-line treatment for many symptomatic patients. By electrically isolating the areas around the pulmonary veins where AF is triggered, ablation restores and maintains normal rhythm far more effectively than tablets alone, with success rates of around seventy to eighty per cent for paroxysmal AF, rising further with a second procedure where needed.

Atrial flutter ablation

Atrial flutter arises from a single re-entry circuit, usually in the right atrium. Because the circuit is so well defined, ablation is quick, low-risk and succeeds in more than ninety-five per cent of cases, making it first-line treatment for most people with flutter.

Supraventricular tachycardia (SVT) ablation

SVT causes sudden episodes of a racing heart, often in otherwise healthy younger people. Ablation cures the underlying short-circuit, including AVNRT and accessory pathways, in over ninety-five per cent of cases, freeing patients from both symptoms and daily medication.

Ventricular tachycardia (VT) ablation

VT arises from the pumping chambers and needs specialist assessment, as it can be life-threatening. In carefully selected patients, ablation reduces VT episodes and painful defibrillator shocks, performed in specialist London electrophysiology centres.

AV node ablation

Where AF cannot be controlled by other means, ablating the atrioventricular node and implanting a pacemaker provides definitive rate control and excellent symptom relief, a "pace and ablate" strategy reserved for the right circumstances.

What happens during the procedure?

Ablation is performed in a specialist electrophysiology laboratory, under sedation or general anaesthetic depending on the procedure. Catheters are guided to the heart under X-ray and advanced 3D mapping, the abnormal tissue is identified and treated, and the catheters are removed. Most procedures take one to three hours, and the majority of patients go home the same day or the following morning.

Success rates, benefits and risks

Success depends on the rhythm being treated: highest for SVT and flutter, and very good for AF, particularly when performed early in the condition's course, one reason not to delay specialist assessment. Beyond symptom relief, successful ablation frequently means less medication, restored confidence and, in AF, evidence of better long-term outcomes when rhythm control is achieved early.

Serious complications are uncommon but include bleeding or bruising at the groin, and rarer risks of damage to the heart's normal wiring requiring a pacemaker, stroke or perforation. We will give you honest, personalised numbers, not averages, before any decision is made.

Recovery and aftercare

Most people are back to desk work within a few days and normal exercise within one to two weeks. After AF ablation, a blanking period of up to three months is normal, during which occasional palpitations do not mean the procedure has failed. We arrange structured follow-up with ambulatory ECG monitoring to confirm success, review medication and continue treating the whole person: weight, sleep, alcohol and blood pressure all strongly influence whether AF stays away.

Frequently asked questions

Is catheter ablation painful?

Most ablations are performed under sedation or general anaesthetic, so you feel little or nothing during the procedure itself. Afterwards, some chest ache or bruising at the groin for a few days is common and settles with simple painkillers.

Will I still need blood thinners after AF ablation?

For at least two to three months, yes, while the treated tissue heals. Beyond that, the decision rests on your underlying stroke risk rather than on how successful the ablation feels: for many patients with risk factors, anticoagulation continues long term even in normal rhythm, and we will explain your individual position clearly.

Can atrial fibrillation come back after ablation?

It can, which is why success rates are quoted honestly rather than promised. Early recurrences during the three-month blanking period often settle on their own. Later recurrence is less common, and a second procedure, targeting any recovering electrical connections, lifts long-term success rates further. Addressing weight, sleep apnoea, alcohol and blood pressure meaningfully improves the durability of any ablation.

How soon will I know whether it has worked?

Symptoms usually tell part of the story, and monitoring tells the rest. We typically review you with prolonged heart-rhythm monitoring around three months after the procedure, giving an objective measure of your rhythm rather than relying on how you happen to feel on a single day.

When can I fly and exercise again?

Short-haul travel is generally reasonable within a week or two, and gentle exercise can resume within days once the groin has healed. We will agree a personal timetable with you, particularly for longer flights and higher-intensity training.

Why choose Dr Assomull?

Accurate diagnosis is everything in rhythm medicine. Dr Assomull will establish precisely which arrhythmia you have, using tools from a simple ECG to prolonged monitoring, treat what can be treated with lifestyle and medication, and refer you to the most appropriate electrophysiologist in his trusted London network when ablation is the right answer, remaining your consistent point of care before and after the procedure at 68 Harley Street.

If palpitations or a diagnosed arrhythmia are affecting your life, book a consultation and get a clear, expert plan.