Catheter Ablation for Heart Rhythm Disorders (Arrhythmias)

Medicines are often the first treatment for abnormal heart rhythms (arrhythmias). While drug therapy can be effective, it has important limitations. Some patients do not respond well, others experience side effects, and certain medications can paradoxically trigger dangerous rhythms (a problem called proarrhythmia). For people with symptomatic or potentially life-threatening arrhythmias, non-pharmacologic treatments play a critical role. These include catheter ablation, implantable devices such as defibrillators, and, in selected cases, cardiac surgery.

This page focuses on catheter ablation, a minimally invasive and highly effective therapy used to treat many common and complex arrhythmias.

What Is Catheter Ablation? Catheter ablation is a procedure in which a cardiologist trained in heart rhythm disorders (an electrophysiologist) uses thin, flexible tubes called catheters to deliver energy to precise areas of heart tissue responsible for abnormal electrical signals. The goal is to eliminate or isolate the source of the arrhythmia while preserving normal heart function.

The procedure is performed as part of an invasive electrophysiology (EP) study, which maps the heart’s electrical activity in real time.

When Is Catheter Ablation Used? Catheter ablation has become a cornerstone therapy for many tachyarrhythmias (fast heart rhythms). It may be recommended as first-line therapy in some conditions or after medications fail or cause side effects.

Common Indications Catheter ablation is commonly used to treat:

• Atrioventricular reentrant tachycardia (AVRT) Including cases related to accessory pathways, such as those seen in Wolff–Parkinson–White (WPW) syndrome.

• AV nodal reentrant tachycardia (AVNRT) One of the most frequent causes of sudden episodes of rapid heart rate.

• Atrial fibrillation (AF) Ablation may be performed with curative intent (pulmonary vein isolation) or, in selected cases, as AV nodal ablation combined with pacemaker implantation to control symptoms.

• Atrial flutter A highly treatable arrhythmia with excellent success rates using ablation.

• Atrial tachycardia Either focal (originating from a single site) or multifocal; some originate near the sinus node.

The effectiveness, risks, and long-term outcomes of ablation vary depending on the type of arrhythmia and patient-specific factors.

Pre-Procedure Evaluation and Monitoring Because catheter ablation is performed during an EP study, pre-procedure preparation and intra-procedure monitoring are essentially the same as for diagnostic electrophysiology testing.

This typically includes:

• Review of symptoms and prior rhythm recordings
• Cardiac imaging, when indicated
• Blood tests and medication review
• Continuous monitoring of heart rhythm, blood pressure, and oxygen levels during the procedure

These steps ensure the procedure is performed safely and accurately.

Energy Sources Used in Catheter Ablation Several energy modalities are used to create controlled lesions in heart tissue. The choice depends on the arrhythmia type, location, and patient factors.

Radiofrequency (RF) Ablation Radiofrequency energy is the most widely used ablation technique.

• Delivers low-voltage, high-frequency electrical energy
• Produces controlled heating of tissue, resulting in precise, focal lesions
• Modern systems use saline-irrigated catheters, which cool the catheter tip and: - Prevent protein buildup - Allow creation of deeper and more durable lesions - Improve long-term success rates

Because RF energy does not directly stimulate nerves or heart muscle, the procedure is usually well tolerated, and general anesthesia is often not required. In selected cases, RF energy may also be applied from the epicardial (outer heart) surface via a pericardial approach.

Cryothermal (Cryo) Ablation Cryothermal ablation uses extreme cold to modify or destroy abnormal tissue. Key advantages include:

• Ability to perform reversible “cold mapping”
• If mild cooling has the desired effect, deeper freezing is applied for permanent ablation
• If unwanted effects occur, the tissue can be rewarmed without lasting damage

This feature makes cryoablation particularly useful when working near critical structures, such as the normal conduction system.

Pulsed Field Ablation (PFA) Pulsed field ablation is a newer technology that is now approved for the treatment of atrial fibrillation and is being studied for ventricular arrhythmias.

• Uses ultra-short, high-voltage electrical pulses
• Causes cell death through electroporation, not heat
• Appears to be selective for heart muscle, with less effect on nearby tissues such as the esophagus, nerves, and blood vessels

PFA represents a promising advance, particularly for improving safety in complex ablation procedures.

Benefits and Limitations of Catheter Ablation Benefits

• High success rates for many arrhythmias
• Reduced or eliminated need for long-term medications
• Improved quality of life and symptom control
• Minimally invasive with short recovery time

Limitations

• Not all arrhythmias are curable
• Some patients may require repeat procedures
• Small risk of complications, which varies by arrhythmia type and technique

Key Takeaways

• Catheter ablation is a highly effective, evidence-based treatment for many cardiac arrhythmias.
• It is often preferred when medications fail, cause side effects, or are not appropriate.
• Multiple energy sources—radiofrequency, cryothermal, and pulsed field—are available, each with specific advantages.
• Careful patient selection and expert electrophysiology evaluation are essential for optimal outcomes.

KIMSHEALTH Approach At KIMSHEALTH, catheter ablation is performed by experienced electrophysiologists using advanced mapping systems and modern energy technologies. Treatment decisions are individualized, evidence-based, and focused on long-term rhythm control and patient safety.

If you experience recurrent palpitations or rapid heartbeats or have been diagnosed with an arrhythmia, consult the KIMSHEALTH Cardiac Electrophysiology Team to determine whether catheter ablation is the right option for you.