What is Atrial Fibrillation?

Atrial fibrillation (AF) is a disorganised arrhythmia affecting the top chambers of the heart, known as the atria. It is the most common sustained heart rhythm disorder and one of my particular areas of expertise. When I was in medical school, I was taught that AF is a purely chaotic and random rhythm. However, we now know that this is not entirely the case. The underlying mechanisms are more structured, driven by fibrosis and disrupted electrical conduction in the atria.

AF often develops due to ageing, high blood pressure, diabetes, and even long-term endurance exercise. Over time, these factors cause scarring (fibrosis) in the atria, which slows and disrupts electrical conduction. The veins leading to the back of the heart, particularly the pulmonary veins, normally dampen extra beats. However, when fibrosis alters this electrical balance, these veins start firing off ectopic beats that spread through the atrium. If enough scarring is present, these signals can trigger a self-perpetuating cycle, leading to rapid and irregular heartbeats. This chaotic rhythm then conducts to the ventricles, causing an erratic and often fast heartbeat.

Why Does Atrial Fibrillation Matter?

AF presents several risks, the most serious being the risk of stroke. The left atrial appendage, a small reservoir in the left atrium, is particularly prone to blood pooling when the atria are not contracting effectively. This can lead to clot formation, which, if dislodged, can travel to the brain and cause a stroke. The risk of this happening depends on various factors such as age, high blood pressure, diabetes, and previous strokes. Most patients with AF require anticoagulant (blood-thinning) medication to significantly reduce this risk, bringing their stroke likelihood back down to near-normal levels.

Another major concern is the effect of AF on the heart's pumping ability. If the heart beats too fast for prolonged periods, it can weaken the heart muscle, leading to a condition known as tachycardia-induced cardiomyopathy. This can cause heart failure, where the heart struggles to pump blood effectively. To prevent this, controlling the heart rate is critical. Medications such as beta-blockers or calcium channel blockers are often prescribed, and in some cases, digoxin may be added. For some individuals, rate control alone is insufficient, and restoring a normal heart rhythm becomes a priority.

Restoring Normal Rhythm

For many patients, maintaining a normal heart rhythm improves symptoms and prevents long-term heart damage. There are two primary approaches to achieving this: medication or procedural interventions.

One method is cardioversion, where an electric shock is used to reset the heart’s rhythm. This is often combined with antiarrhythmic drugs, such as amiodarone, which help maintain normal rhythm. However, long-term use of these medications carries significant side effects, and for many patients, they are not a viable option over extended periods.

Catheter Ablation: A More Effective Long-Term Solution

The limitations of medication have led to the development of catheter ablation, a procedure designed to target the underlying triggers of AF directly. Ablation involves threading thin catheters through the blood vessels into the heart and using energy to modify or destroy problematic electrical pathways, typically around the pulmonary veins. This prevents ectopic beats from initiating AF, significantly reducing its recurrence.

Traditionally, radiofrequency or cryoablation has been used, both of which have been effective but come with some risks, such as collateral damage to surrounding structures. However, a new technique called pulsed field ablation (PFA) is revolutionising how we treat AF. Instead of using heat or extreme cold, PFA delivers ultra-short electrical pulses that selectively target heart muscle cells without damaging surrounding tissues such as the oesophagus or nerves.

I have been using PFA in my practice and achieving outstanding results. The precision and safety profile of this technology mean that patients experience fewer complications and shorter recovery times. In fact, our latest data on PFA treatment has shown excellent success rates, and we will be publishing these results soon.

What Does Treatment Look Like for AF?

For most patients, treatment decisions are based on their symptoms and risk factors. The approach typically follows a sequence:

·        Assess Stroke Risk If stroke risk is high, anticoagulation is prescribed.

·        Control Heart Rate Medications are used to prevent excessively fast heart rates.

·        Evaluate the Need for Rhythm Control: If symptoms persist or heart function is affected, cardioversion, medication, or ablation is considered.

·        Perform Ablation if Necessary: For many patients, ablation—particularly using advanced techniques like PFA—offers the best chance of long-term success.

What if Ablation Fails?

First-time success rates for AF ablation are typically around 70–80%. However, in patients with persistent AF (where the arrhythmia is present all the time), approximately one-third will need a second procedure. In rare cases, a third ablation may be required. This is usually due to a fast, regular rhythm called atrial flutter, which is closely related to AF but responds very well to ablation treatment.

For some patients who have had AF for a long time or whose atria have been significantly damaged by ageing, high blood pressure, or other conditions, complete elimination of AF may not be possible. In these cases, ongoing medical treatment can often keep symptoms under control. In certain patients, particularly those whose AF cannot be effectively managed with medication or ablation, a pacemaker can be a very good option. While pacemakers do have some downsides, they are a straightforward procedure and can be the right choice for select patients who need more reliable heart rate control.

Living with Atrial Fibrillation

AF can be a challenging condition, but with the right management strategy, most patients can lead normal, active lives and we can prevent those feared complications of Heart Failure or Stroke. The key is a personalised approach, considering factors such as symptom burden, heart function, and stroke risk. Advances in ablation techniques, particularly with PFA, are transforming treatment options and providing better outcomes than ever before.

As research progresses, our ability to manage and potentially cure AF continues to improve. My focus remains on delivering the most effective treatments available, ensuring patients receive the highest standard of care.