Catheter Ablation for AVNRT in Older Adults

Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common regular supraventricular tachycardias treated in the electrophysiology laboratory. Although it often affects younger adults, older patients may present with more complicated symptoms, including syncope, chest discomfort, breathlessness, falls, or worsening heart failure. A rapid narrow-complex rhythm can be particularly poorly tolerated when ventricular compliance, coronary reserve, or autonomic function has declined with age.

Catheter ablation offers a highly effective treatment for symptomatic AVNRT, including in patients aged 75 years and over. The usual target is the slow pathway in the posteroseptal right atrium, close to the atrioventricular node and His bundle. This anatomy makes procedural precision essential, because inadvertent injury to the normal conduction system can result in complete heart block and the need for permanent pacing.

Age alone should not exclude an individual from an invasive rhythm procedure. A careful assessment of frailty, cognition, renal function, vascular access, mobility, bleeding risk, and personal treatment goals gives a more useful estimate of procedural suitability than chronological age alone. For a patient who is still active and independent, eliminating recurrent tachycardia may preserve confidence and reduce emergency presentations.

Australian practice adds practical considerations. Patients in Sydney, Melbourne, Brisbane, Perth, Adelaide, and other metropolitan centres often have access to experienced electrophysiology teams, while people in regional or remote areas may need transfer to a tertiary hospital. Public hospital pathways, private insurance arrangements, Medicare-funded care, and local waiting times can all influence when an ablation is performed.

Clinical Features In Later Life

AVNRT may become harder to recognise in older adults because its symptoms overlap with common cardiovascular and non-cardiovascular conditions. Palpitations may be brief or absent, while dizziness, unexplained falls, fatigue, dyspnoea, or presyncope dominate the clinical picture. A rapid rate can precipitate angina in patients with coronary artery disease or worsen congestion in those with left ventricular dysfunction.

Electrocardiography during an episode usually shows a regular narrow-complex tachycardia, often at 150–250 beats per minute. A pseudo-r’ in V1 or pseudo-S wave in the inferior leads can support the diagnosis, although these findings may be subtle. Documentation from an ambulance, emergency department, implantable monitor, or consumer wearable can help distinguish AVNRT from atrial tachycardia, atrial flutter, and atrial fibrillation.

Acute treatment with vagal manoeuvres or adenosine may terminate the rhythm, but repeated emergency treatment is not a durable strategy for recurrent episodes. Beta blockers or nondihydropyridine calcium-channel blockers may reduce attacks, yet their use can be limited by bradycardia, hypotension, conduction disease, constipation, or drug interactions. These limitations often make definitive ablation attractive for carefully selected older patients.

Selecting Patients For Ablation

The decision should reflect symptom burden, arrhythmia frequency, haemodynamic effect, medication tolerance, and the patient’s goals. A person who has had several emergency department visits, injured themselves during tachycardia-related syncope, or cannot take rate-control medication may gain substantial benefit from ablation. Even infrequent episodes can justify treatment when they cause severe anxiety or major disruption to driving, travel, or independent living.

Pre-procedure review should include a 12-lead ECG, echocardiography when structural disease is suspected, medication reconciliation, renal function, blood count, and assessment of vascular and bleeding risks. Clinicians should look for baseline first-degree atrioventricular block, bundle branch disease, sinus-node dysfunction, previous cardiac surgery, and implanted devices. Frailty screening and a discussion with family or carers can clarify whether same-day discharge and sedation are realistic.

Anticoagulation is not routinely required solely for AVNRT, unlike atrial fibrillation. However, many older patients have coexisting atrial fibrillation, venous thromboembolism, coronary disease, or prior stroke. Their antithrombotic plan must be individualised, especially if femoral venous access is planned. Clear instructions are important when care is shared between a general practitioner, cardiologist, anticoagulation service, and hospital team.

Procedural Strategy And Technology

Most AVNRT procedures use femoral venous access, intracardiac electrophysiology recording, and programmed stimulation to confirm the mechanism. Atrial and ventricular signals demonstrate dual atrioventricular nodal physiology and allow the operator to map the slow-pathway region. Radiofrequency energy is commonly delivered near the coronary sinus ostium and lower Koch’s triangle, with attention to electrogram characteristics and distance from the His recording site.

Radiofrequency ablation generally provides high acute success, often above 95% in experienced centres. Cryoablation is another option, particularly when the anatomy is close to the compact atrioventricular node or when the team places a high value on reversible lesion testing. Cryomapping can identify an unsafe site before a permanent lesion is created, although recurrence may be somewhat higher than with radiofrequency treatment in some series.

Older adults may benefit from a deliberately conservative procedural approach. Limiting contrast, reducing procedure time, using ultrasound-guided venous access, and choosing conscious sedation rather than deep anaesthesia can reduce avoidable physiological stress. The exact plan depends on frailty, airway risk, obstructive sleep apnoea, dementia, and the anticipated ability to remain still.

Safety And The Risk Of Heart Block

The most important complication is damage to the normal atrioventricular conduction system. Contemporary studies report a low risk of permanent atrioventricular block, commonly below 1%, but the consequence is serious. Risk may be higher in patients with pre-existing conduction disease, unusual slow-pathway anatomy, or extensive septal scarring. Operators should explain that a pacemaker may rarely be required even when the procedure is otherwise successful.

Other complications include femoral haematoma, pseudoaneurysm, arteriovenous fistula, pericardial effusion, infection, thromboembolism, and adverse reactions to sedative medication. Vascular complications deserve particular attention in older people with peripheral arterial disease, chronic kidney disease, or anticoagulant use. Early mobilisation protocols and ultrasound-guided access can help reduce risk.

Patients and families sometimes confuse an ablation complication with later device problems. For broader reading on implanted cardiac technology, lead fracture management provides useful context about detecting and managing lead failure. This is separate from routine AVNRT ablation, which does not usually involve placing a new cardiac device.

Efficacy And Outcomes In Elderly Patients

Published cohorts generally show that advanced age does not substantially reduce the acute success of slow-pathway ablation. Long-term freedom from documented AVNRT is also high, with recurrence often reported in the low single digits. When recurrence occurs, it may reflect incomplete slow-pathway modification, recovery of conduction, or an alternative atrial arrhythmia rather than failure of the overall treatment strategy.

The clinical gains can be meaningful. Successful ablation may stop ambulance call-outs, reduce emergency presentations, remove the need for regular antiarrhythmic or rate-control medication, and restore confidence with walking or exercise. Some patients report that their “racing heart” was the main reason they stopped shopping, gardening, or travelling; eliminating the episodes can support a return to ordinary activities.

Outcome interpretation requires care. Older patients may continue to experience palpitations from atrial ectopy, atrial fibrillation, sinus tachycardia, or ventricular ectopy. A post-ablation symptom should therefore be assessed rather than automatically labelled recurrent AVNRT. ECG documentation, ambulatory monitoring, or an implanted monitor can distinguish recurrence from a new rhythm diagnosis.

Recovery And Follow-Up

After uncomplicated femoral venous access, many patients can leave hospital the same day or after overnight observation. Instructions usually cover wound care, heavy lifting, driving, hydration, and warning symptoms such as persistent bleeding, severe chest pain, fainting, fever, or sustained palpitations. Older adults who live alone may need transport, a support person, or a short period of additional observation.

A follow-up review can confirm symptom response, inspect the access site, and reassess medications. Patients with transient skipped beats or brief palpitations soon after ablation may be reassured, although sustained tachycardia requires an ECG. Follow-up should also identify newly recognised atrial fibrillation, which carries its own stroke-prevention implications and is not cured by slow-pathway ablation.

In Australia, post-procedure coordination may involve the electrophysiology clinic, the patient’s local cardiologist, and a GP in a regional town. Telehealth can be useful for reviewing symptoms and medication, while rhythm recordings may be transmitted electronically. Clear escalation pathways are especially important for people travelling from Far North Queensland, Western Australia, Tasmania, or remote communities.

Evidence, Access, And Future Practice

The evidence base for AVNRT ablation in elderly patients is largely drawn from observational cohorts, registries, and subgroup analyses rather than large randomised trials dedicated to advanced age. Even so, the consistency of high success and low major complication rates supports offering the procedure when symptoms are significant and the patient’s overall health permits it. Frailty, comorbidity, and functional goals should remain central to shared decision-making.

Contemporary research is examining zero- or low-fluoroscopy workflows, improved three-dimensional mapping, contact-force assessment, and better methods for identifying the His bundle. These developments may be especially valuable when radiation exposure, renal impairment, or complex anatomy makes conventional approaches less desirable. Training and case selection remain just as important as technology.

Clinicians and trainees can follow current electrophysiology research, clinical reviews, and educational material through the journal’s arrhythmia collections. Such resources help place individual procedural results in the context of evolving guidance, regional practice, and long-term outcome data.

For older adults with symptomatic AVNRT, a structured assessment can turn a recurrent and disruptive rhythm into a treatable problem. Careful mapping, conservative energy delivery, attention to frailty, and coordinated follow-up allow catheter ablation to provide durable relief while keeping procedural risk proportionate to the patient’s needs. Electrophysiology teams, referring clinicians, and patients should use shared decision-making to determine when definitive treatment offers the clearest path to safer, more confident daily life.