Contributed by Asst Prof Julian Tay Cheong Kiat, Consultant, Cardiology

Atrial fibrillation (AF), the most common sustained heart rhythm disorder, is a complex and often misunderstood cardiac condition. While often described simply as "irregular heartbeat," its impact can be serious, and potentially life-threatening, if not properly managed.

AF is a type of arrhythmia, meaning the heart beats with an irregular or often unusually rapid rhythm. Instead of the upper chambers of the heart (the atria) beating in a coordinated way, AF causes them to quiver, affecting blood flow and increasing the risk of stroke, heart failure, and other heart-related complications.

How Common Is AF?

AF affects an estimated 59 million people globally as of 2019¹, with men more commonly affected than women. Its prevalence is increasing exponentially with the ageing population (Figure 2). In the United States alone, around 2.7 to 6.1 million people have AF, and this number is expected to double by 2050. AF becomes more common with age—affecting about 9% of people over 65. In Singapore specifically, AF affects 0.6% of middle-aged adults (45 to 64 years old) and 7% of the elderly (over 65 years old)². People with cardiovascular risk factors such as hypertension, obesity, diabetes, heart disease, and those who consume excessive alcohol face an elevated risk of developing AF.

Figure 2: Prevalence of AF/ atrial flutter in both men and women. (Source: Linz et. al. Atrialfibrillation: epidemiology, screening and digital health. The Lancet: Regional Health 2024)

Detecting and Diagnosing AF

Early detection can prevent complications. Common methods for detecting and diagnosing AF include:

• Electrocardiogram (ECG or EKG): Standard, painless test that records the heart's electrical signals and remains the gold standard for AF diagnosis.
• Non-invasive monitors (e.g. Holter Monitors): Portable ECG devices worn for a minimum of 24 hours and up to two weeks to detect intermittent AF episodes that may not appear during a standard ECG.
• Event recorders and implantable loop recorders: Monitor heart rhythms over longer periods, especially for people with infrequent symptoms.
• Smart devices: Modern smartwatches and mobile apps can now detect irregular heart rhythms and suggest possible AF, leading to more people seeking early medical attention.

Treatment Options: From Medications to Catheter Ablation

The goals of AF management are to restore normal rhythm, control heart rate, and prevent stroke. Treatments include:

Medications

• Rate control medications: Beta-blockers, calcium channelblockers, and digoxin help slow the heart rate.
• Rhythm control medications (antiarrhythmics): Restore andmaintain a normal heart rhythm.
• Blood thinners (anticoagulants): Lower the risk of stroke bypreventing blood clots forming in the heart due to AF.

Cardioversion

This procedure uses either electric shock or medications to reset theheart's rhythm in patients who have persistent AF.

Catheter Ablation – A Revolution

Catheter ablation is a minimally invasive procedure that targetsthe electrical "hot spots" causing AF. During this procedure, a thin,flexible tube called a catheter is threaded through blood vessels intothe heart. Energy—traditionally in the form of radiofrequency (heat)or cryotherapy (freezing)—is delivered to destroy small areas of tissue responsible for abnormal signals.

Figure 3: Diagram of the three distinct catheter ablation technologies in treating AF. A) Radiofrequency ablation which uses thermal heat energy. B) Cryoballoon ablation which uses thermal cold energy. C) Pulsed field ablation which uses controlled electrical energy. (Source: Zhang et. al. Device therapy for patients with atrial fibrillation and heart failure with preserved ejection fraction. Heart Failure Reviews 2023)

Latest Innovations: Pulsed Field Ablation and Beyond

While traditional ablation methods have been life-changing for many, they also carry risks of collateral damage to nearby structures, such as the oesophagus, phrenic nerve or even the pulmonary veins. Recent technological advances address these challenges head-on.

Pulsed field ablation (PFA) is an exciting, relatively new technology that uses short, high-voltage electrical pulses to create tiny holes in cell membranes—this process is known as electroporation. This innovative approach selectively destroys only the heart tissue causing AF without harming surrounding organs.

Key Advantages:

• Precision: PFA targets abnormal heart cells specifically, reducing the risk to other tissues.
• Speed: The procedure is typically faster than traditional ablation techniques.
• Safety: Early studies show a lower risk of complications,such as damage to the oesophagus, compared with heat- orfreeze-based ablation.
• Effectiveness: Initial clinical trials suggest outcomes are atleast as good as, if not better than, conventional ablation.

Beyond PFA, other technological advances are enhancing catheter ablation procedures. Three-dimensional mapping systems, robotic navigation and adjunctive high-resolution imaging such as computed tomography (CT), magnetic resonance imaging (MRI) and intracardiac echocardiography (ICE) are making catheter ablation safer and more effective. Such technologies allow physicians to visualise the heart in real-time, improving precision and outcomes.

All these developments are transforming the landscape for AF treatment. PFA and other cutting-edge technologies are opening new horizons, offering hope to those who have not responded well to medications or traditional ablation methods. For patients with AF, this means more options, fewer complications, and better quality of life.

REFERENCES

1. Linz D, Gawalko M, Betz K, et al. Atrial fibrillation: epidemiology, screening and digital health. The Lancet Regional Health - Europe. 2024;37. doi:10.1016/j.lanepe.2023.100786

2. Tan ESJ, Zheng H, Ling JZJ, et al. Sex and ethnicity modified high 1-year mortality in patients in Singapore with newly diagnosed atrial fibrillation. Ann Acad Med Singap. 2022;51(9). doi:10.47102/annals-acadmedsg.2022203

3. Ko D, Chung MK, Evans PT, Benjamin EJ, Helm RH. Atrial Fibrillation: A Review. JAMA. 2025;333(4):329–342. doi:10.1001/jama.2024.22451