Pulsed Field Ablation (PFA)

Treatment for Atrial Fibrillation

Atrial fibrillation (AF) can be unsettling. The condition not only causes an irregular heart rhythm, but can also lead to blood clot formation in the heart, resulting in a higher risk of stroke and heart failure. Apart from using medication, AF recurrence is traditionally prevented through a procedure known as ablation, though this method carries risk of complications. Pulsed field ablation (PFS), a groundbreaking treatment newly introduced in Hong Kong, significantly reduces the risk of complications and shortens surgery time by more than half. For the over 70,000 AF patients in Hong Kong (approximately 1% of the total population), PFA offers renewed hope for an alternative, improved treatment method.

A common treatment method for AF is taking medications such as anticoagulants (blood thinners) and anti-arrhythmics. However, medication does not cure AF, and some patients may opt for surgery to reduce the risk of AF recurrence. Traditionally, a procedure known as pulmonary vein isolation is conducted to target abnormal cells that are causing AF at the junction of the atria and pulmonary veins. By using heat or cold energy, this type of cardiac ablation creates tiny scars to block irregular heart rhythms. 

However, pulmonary vein isolation has its risks. During the procedure, surrounding tissues may be affected, resulting in rare complications such as pulmonary vein stenosis or atrial-esophageal fistula (AEF) – the formation of an abnormal connection between the left atrium of the heart and the esophagus. There is also risk of phrenic nerve injury, which can lead to diaphragmatic paralysis and affect a patient’s ability to breathe. Furthermore, the procedure is relatively lengthy and takes at least two to three hours to complete.

Pulsed field ablation (PFA), introduced in Hong Kong this year, reduces risk of complications and significantly shortens the procedure time. Through delivery of a series of high-voltage electrical pulses that last just a few seconds, the procedure aims to destroy abnormal cells causing AF by creating numerous pores in the cell membranes.

As the electric field response threshold for the abnormal cells differs from that of nerve cells and esophageal cells, the specific voltage and duration of the electrical pulses may be adjusted to target the abnormal cells without endangering the surrounding tissues, thereby reducing the risk of complications. In addition, the procedure requires just over one hour to complete, less than half the time needed for traditional ablation. 

In terms of recurrence prevention, the rates of PFA and traditional ablation are comparable. Within one year following the procedure, over 80% of patients with paroxysmal AF and about 70% of patients with persistent AF do not experience recurrence. 

There are multiple treatments for AF, each with varying levels of effectiveness and risk of complications. Patients with questions should consult their attending physician for more information.