Cold Energy Source
Cryoablation
Cryoablation uses controlled cooling to treat selected heart tissue involved in an abnormal rhythm. It is most often discussed in connection with pulmonary vein isolation.
On this page
Understanding the technology
What Is Cryoablation?
Cryoablation is a catheter-based treatment that uses controlled cold energy to create small areas of treated tissue in the heart. The aim is to interrupt an abnormal electrical pathway or trigger.
It is planned after assessment of the rhythm. This page describes the cooling energy source. For the overall procedure, see Catheter Ablation.
Cryoablation catheter, conceptual
The principle
How Cryo Works
A cooling agent circulates inside the tip or balloon of the catheter. When the catheter contacts the tissue, the contact area cools and the cells in that area are changed.
The treated tissue no longer conducts electrical signals in the same way. The team monitors the temperature and the electrical response while energy is applied.
Conceptual illustration of cooling at the catheter
Delivery system
Cryoballoon
A cryoballoon is a balloon at the end of a catheter. It is guided to the opening of a pulmonary vein and inflated so that it sits against the surrounding tissue. Cooling is then delivered around the opening.
Balloon positioning
The balloon is placed at the vein opening and checked for contact.
Contact assessment
The team assesses how well the balloon seals the opening before cooling.
Cooling delivery
Cooling is applied for a set period, which the operator selects.
Catheter options
Focal cryo catheters may also be used for selected targets.
A common use
Pulmonary Vein Isolation
In atrial fibrillation, extra electrical activity often starts near the pulmonary veins. Pulmonary vein isolation aims to electrically separate these veins from the rest of the left atrium. Cryoballoon ablation is one way to do this.
Whether this approach suits a person depends on the rhythm, the anatomy and the physician assessment. For the condition itself, see Atrial Fibrillation.
Before and during treatment
Electrophysiology and Assessment
Treatment is planned from the history, ECG and rhythm monitoring, and sometimes imaging. During the procedure, electrical recordings help show whether the treated area still conducts. For the diagnostic study, see Electrophysiology Study.
Patient journey
Procedure Pathway
A general outline for a cryoballoon procedure. The steps depend on the patient and the findings.
Assessment
Review of symptoms, history and tests.
Access
Catheters are introduced through a vein, usually in the groin.
Access to the left atrium
A catheter is guided across to the left atrium.
Balloon positioning
The balloon is placed at each pulmonary vein opening.
Seal check
Contact with the vein opening is assessed.
Cooling
Cooling is delivered at each vein, as planned.
Electrical check
Recordings show whether the vein is isolated.
Recovery
Monitoring while the patient recovers.
Clinical context
Clinical Use
Cryoablation may be considered for some patients, most often for pulmonary vein isolation in atrial fibrillation. Having one of these conditions does not mean cryoablation is needed.
Type of arrhythmia
Some rhythm problems suit one energy source better than another.
Treatment strategy
The plan may involve one or several targets.
Patient factors
Anatomy, other conditions and preferences are considered.
Physician assessment
The choice is made by the treating physician.
Comparison
RF vs Cryo vs PFA
The three energy sources work in different ways. This is a comparison of mechanism only, not a ranking.
Energy source
Radiofrequency
Controlled thermal heating of a small area of tissue.
This page
Cryoablation
Controlled freezing of selected tissue.
Energy source
Pulsed field ablation
Short pulsed electrical fields applied to tissue.
The choice depends on the arrhythmia, the procedure plan and the individual patient.
Recovery and follow-up
Follow-up
After the procedure you are monitored while you recover. Follow-up depends on the rhythm treated and on how you are. It may include a review of symptoms and rhythm checks.
Seek urgent medical care for fainting, chest pain or severe breathlessness.
Choosing the technique
Why Cryoablation May Be Chosen
Cryoablation freezes tissue with a cooled catheter tip or balloon. During treatment the catheter adheres gently to the tissue, which can help keep it stable. In some situations a short, reversible cooling step can be used to check the effect before a lasting lesion is made.
It may be selected in certain anatomical situations, or when the target lies near sensitive conduction structures, such as the AV node region in some supraventricular tachycardias, where the team wishes to proceed with particular care.
In atrial fibrillation, a cryoballoon is positioned at the opening of each pulmonary vein to treat the tissue around it and isolate the vein. See Atrial Fibrillation Ablation.
Cryoablation is one of several energy options. The choice depends on the rhythm, the anatomy, the team’s experience and the equipment available, and it is not better or worse in every case. See Radiofrequency Ablation and Pulsed Field Ablation.
Questions
Frequently Asked Questions
What is cryoablation?
What is a cryoballoon?
Is cryoablation used for atrial fibrillation?
Is it different from radiofrequency ablation?
Does everyone need cryoablation?
Is the treatment always successful?
What happens after the procedure?
How does cryoablation compare with RF and PFA?
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