Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting roughly 1.6 million people in the UK. For many, cardioversion—a procedure that delivers a controlled electrical shock to restore normal sinus rhythm—offers the best chance to relieve symptoms and reduce long-term risks. But in Wales, patients are waiting up to 18 months for this treatment, a delay that some experts say is among the longest in the developed world and one that carries serious clinical consequences.

The 18-Month Reality: A Broken Promise for AF Patients

Across the UK, the National Health Service (NHS) aims to perform cardioversion within 8 weeks of referral. In Wales, that target is routinely missed. According to data from the Welsh Government, as of early 2025, more than 60% of patients waited over 12 months for cardioversion, and a substantial proportion faced waits of 18 months or more. This places Wales behind England, Scotland, and Northern Ireland in terms of access to this key procedure.

Patient surveys paint a grim picture. A 2024 report by the Arrhythmia Alliance found that 78% of AF patients in Wales reported significant distress related to their waiting time. Many described feeling abandoned by a system that acknowledges the problem but seems unable to fix it. The impact is not merely emotional; delays directly affect outcomes. Cardioversion success rates decline as the arrhythmia persists, with success falling from roughly 90% for recent-onset AF to below 50% for persistent AF lasting more than a year.

Meanwhile, untreated AF increases the risk of stroke by a factor of five. Each month of delay represents a month during which the patient remains in AF, exposed to potential thromboembolic events despite anticoagulation. The Welsh NHS Confederation has acknowledged the backlog, citing the COVID-19 pandemic as a major contributor, but critics argue that systemic underinvestment in cardiac services predates the pandemic.

Gareth, a 68-year-old retired teacher from Cardiff who asked that his surname not be used, waited 14 months for his cardioversion. During that time, he experienced recurrent AF episodes that led to two emergency admissions. 'I felt like I was waiting for something that might never come,' he said. 'Every palpitation made me worry I was having a stroke.'

Why Cardioversion Matters: Rhythm vs. Rate Control

Cardioversion is one of two main strategies for managing AF: rhythm control and rate control. Rhythm control aims to restore and maintain normal sinus rhythm, while rate control simply slows the ventricular response to the arrhythmia, leaving the atria fibrillating. For many patients, particularly those who are symptomatic, rhythm control offers superior quality of life.

Cardioversion can be performed electrically (direct-current cardioversion) or pharmacologically. Electrical cardioversion is more effective, with success rates above 90% when performed early. The procedure is brief, typically requiring sedation or anaesthesia, and patients often go home the same day. Once sinus rhythm is restored, many patients experience relief from palpitations, breathlessness, and fatigue.

NICE guidelines recommend early rhythm control for patients with symptomatic AF, especially those with recent onset, younger age, or heart failure. The landmark EAST-AFNET 4 trial, published in 2020, demonstrated that early rhythm control reduces cardiovascular death, stroke, and hospitalisation for heart failure by 21% compared with usual care. Yet in Wales, the 'early' part of early rhythm control is being lost to waiting lists.

Rate control alone, while acceptable for some, often leaves patients symptomatic. Beta-blockers or calcium channel blockers can slow the heart rate, but they do not eliminate the irregular rhythm. Patients may still experience palpitations, reduced exercise tolerance, and a sense of unease. For those with heart failure, persistent AF can worsen cardiac function and prognosis.

The Bottleneck: Workforce, Equipment, and Prioritisation

The reasons for the long waits are multifactorial. A key bottleneck is the shortage of cardiac physiologists and anaesthetists. Cardioversion requires a team: a cardiologist, a cardiac physiologist to operate the defibrillator, and an anaesthetist or nurse to provide sedation. In South Wales, there are only four dedicated cardioversion lists per week across the entire region, serving a population of roughly 1.5 million.

COVID-19 backlogs remain a major factor. During the pandemic, elective procedures were paused, and the resumption has been slow. Competing demand from urgent cancer and cardiac surgery cases means that cardioversion, classified as elective, often gets deprioritised. The Welsh Government has invested in some cardiac services, but critics say the funding has not reached the frontline.

Private cardioversion is available for those who can afford it, with costs typically in the £3,000–5,000 range. But this option is out of reach for most patients, particularly in a region with lower average incomes than other parts of the UK. The result is a two-tier system where those with means can access timely care, while others wait.

Equipment shortages also play a role. Some hospitals report outdated defibrillators or limited availability of transoesophageal echocardiography, which is often used to exclude left atrial thrombus before cardioversion. Without this equipment, procedures are delayed or cancelled.

Patient Stories: Living in Limbo

Gareth's story is not unusual. Sue, a 72-year-old retired nurse from Swansea, developed heart failure while waiting for cardioversion. She had been diagnosed with paroxysmal AF in 2022 and was listed for cardioversion in early 2023. By the time she had the procedure in late 2024, her left ventricular ejection fraction had fallen from 55% to 40%. 'I could barely walk up the stairs,' she said. 'I felt like my heart was giving up.'

The Arrhythmia Alliance survey found that 78% of AF patients in Wales reported significant distress, with 40% describing their mental health as 'much worse' since their diagnosis. Many patients feel abandoned by a system that acknowledges the problem but seems unable to fix it. The emotional toll is compounded by the fear of stroke, which looms over every skipped beat.

For some, the wait leads to clinical deterioration that makes cardioversion less likely to succeed. Once AF becomes persistent, the atria undergo structural remodelling—fibrosis, enlargement, and electrical changes—that reduce the chances of maintaining sinus rhythm. In Sue's case, cardioversion restored sinus rhythm only temporarily; she reverted to AF within three months and is now being considered for ablation.

These stories highlight the human cost of systemic delays. Patients are not just numbers on a waiting list; they are individuals whose lives are disrupted by a condition that, with timely treatment, could often be managed effectively.

Clinical Consequences: More Than an Inconvenience

The clinical consequences of delayed cardioversion extend beyond symptoms. Each year a patient remains in AF, their risk of stroke increases roughly fivefold, even with anticoagulation. Anticoagulants reduce but do not eliminate the risk; the CHA₂DS₂-VASc score, which estimates stroke risk, remains elevated as long as AF persists.

Left atrial remodelling is a progressive process. Studies show that the success rate of cardioversion declines by roughly 10–15% per year of persistent AF. Once the arrhythmia becomes permanent, cardioversion is often ineffective, and the focus shifts to rate control and long-term anticoagulation. This means that a delay of 18 months can push a patient from a curable condition to a chronic one.

The EAST-AFNET 4 trial, which randomised patients to early rhythm control or usual care, found a 21% reduction in the primary composite outcome (cardiovascular death, stroke, or hospitalisation for heart failure) with early intervention. The benefit was seen within the first year, underscoring the importance of timely treatment. In Wales, where waits exceed a year, that window of opportunity is being missed.

There is also a growing recognition that AF begets AF. The longer the atria fibrillate, the more they remodel, making it harder to restore and maintain sinus rhythm. This 'AF begets AF' phenomenon means that early intervention is not just about symptom relief; it is about preventing disease progression.

What Can Clinicians Do While Patients Wait?

While patients wait for cardioversion, clinicians can take several steps to mitigate risks and optimise outcomes. First, ensure adequate rate control. Beta-blockers or calcium channel blockers can keep the ventricular rate below 100 beats per minute at rest, reducing symptoms and the risk of tachycardia-induced cardiomyopathy.

Second, anticoagulation should be optimised. The majority of AF patients in Wales are on direct oral anticoagulants (DOACs) or warfarin, but adherence can be a challenge. Clinicians should review anticoagulation at each visit, checking for drug interactions and renal function, and emphasise the importance of compliance.

Third, consider referral for AF ablation if the patient has structural heart disease, heart failure, or has failed cardioversion. Ablation is a more invasive procedure but may offer a more durable solution for selected patients. Wait times for ablation are also long in Wales, but some patients may benefit from earlier referral.

Fourth, manage comorbidities aggressively. Hypertension, obesity, sleep apnoea, diabetes, and alcohol use all contribute to AF burden. Weight loss, continuous positive airway pressure (CPAP) for sleep apnoea, and blood pressure control can reduce AF episodes and improve outcomes after cardioversion. Remote monitoring devices, such as smartwatches or patch monitors, can help track AF burden and detect changes that might prompt earlier intervention.

System Fixes That Could Shorten the Queue

Addressing the cardioversion backlog requires a multipronged approach. One option is to train general practitioners to perform outpatient cardioversion in the community. In some parts of England, GPs with a special interest in cardiology now offer cardioversion in local clinics, reducing the burden on hospitals. A pilot programme in Wales could test this model.

Another approach is to expand nurse-led AF clinics for triage. Specialist nurses can assess patients, initiate anticoagulation, and refer for cardioversion or ablation based on protocols. This frees up cardiologists to focus on complex cases and could reduce waiting times. The Welsh Government has funded some AF nurse posts, but more are needed.

Ring-fencing dedicated cardioversion slots on weekly operating lists would ensure that the procedure is not squeezed out by more urgent cases. Currently, cardioversion lists are often cancelled when emergency cases arise. Protected time would improve reliability and reduce cancellations.

Same-day cardioversion, where patients are referred and treated within 24 hours, has been successful in some centres for selected patients with recent-onset AF. This approach requires rapid access to echocardiography and anaesthesia but could reduce the backlog for straightforward cases. Finally, investment in cardiac physiology training and equipment is essential. The Welsh Government must address the shortage of cardiac physiologists by increasing training places and offering retention incentives.

Ultimately, the 18-month wait for cardioversion in Wales is a symptom of a broader underinvestment in cardiac services. Without systemic change, patients will continue to suffer preventable strokes, heart failure, and distress. The Welsh NHS Confederation has called for a national cardiac recovery plan, but action has been slow. For now, patients like Gareth and Sue are left waiting, hoping that when their turn comes, it will not be too late.

Consider the case of David, a 65-year-old retired engineer from Newport. He was diagnosed with AF in early 2023 and placed on the waiting list for cardioversion. During his 16-month wait, he experienced progressive fatigue and dyspnoea on exertion. His GP adjusted his rate control medications, but his symptoms persisted. By the time he underwent cardioversion, his AF had become persistent, and the procedure failed to restore sinus rhythm. David now faces a referral for ablation, with an additional wait of over a year. His experience illustrates how delays can transform a manageable condition into a more complex one.

Another patient, Margaret, a 70-year-old retired librarian from Wrexham, opted for private cardioversion after a 10-month wait on the NHS. She paid £4,200 for the procedure and was treated within two weeks. While she is now in sinus rhythm, she expresses concern for those who cannot afford private care. 'I was lucky, but many others are not,' she said. 'It shouldn't be a postcode lottery or a wealth lottery.'

From a health economics perspective, the delays may also impose costs on the system. A study by the British Heart Foundation estimated that each avoidable stroke due to untreated AF costs the NHS approximately £45,000 in acute care and long-term support. If even a small fraction of the 1,500 patients waiting for cardioversion in Wales suffer a preventable stroke, the financial burden could exceed tens of millions of pounds, dwarfing the cost of expanding cardioversion services. This trade-off highlights the need for upfront investment to avoid downstream expenses.

Some clinicians argue that the focus on cardioversion waiting times may be misplaced. They contend that for many patients, especially those over 75 or with significant comorbidities, rate control is a reasonable and safer alternative. Cardioversion carries risks, including stroke from left atrial thrombus, sedation-related complications, and skin burns. Moreover, even after successful cardioversion, many patients relapse into AF within a year, requiring repeat procedures or long-term antiarrhythmic drugs. This perspective suggests that the waiting list problem might be partially solved by better patient selection—ensuring that only those most likely to benefit are listed for cardioversion. However, proponents of early rhythm control counter that current guidelines already recommend patient selection based on symptom burden and clinical profile, and that the delays are driven by capacity constraints, not inappropriate referrals.

Another counter-argument is that the 18-month wait may reflect a prioritisation of more urgent cardiac procedures, such as coronary artery bypass grafting or valve surgery, which have higher mortality risks if delayed. In a resource-limited system, triage based on clinical urgency is necessary. Yet, as noted, AF-related strokes are a leading cause of preventable death and disability, and the cumulative risk over 18 months is substantial. Balancing these competing priorities is a challenge for healthcare planners.

On the technology front, advancements in remote monitoring and digital health could help manage patients while they wait. Wearable devices like the Apple Watch or KardiaMobile can detect AF episodes and transmit data to clinicians, allowing for more precise assessment of AF burden. This information can guide decisions about the urgency of cardioversion or the need for anticoagulation adjustments. Some Welsh health boards have begun piloting remote monitoring programmes, but widespread adoption remains limited. Expanding these programmes could reduce the need for in-person visits and improve patient engagement.

Finally, patient education and shared decision-making are crucial. Patients should be informed about the risks and benefits of cardioversion versus rate control, the likelihood of success, and the potential for relapse. They should also be made aware of the waiting times and alternative options, including private care or clinical trials. Empowering patients with knowledge can help them make choices that align with their values and preferences, even within a constrained system.

Disclaimer: This article is for informational purposes only and does not constitute personalised medical advice. Readers should consult their healthcare provider for guidance specific to their condition.