What is done during a cardiac ablation for atrial fibrillation?

From the Guidelines

Cardiac ablation for atrial fibrillation is a procedure that creates small scars in the heart tissue to block abnormal electrical signals causing the irregular heartbeat, with a success rate of approximately 80% in patients with paroxysmal AF and 60-70% in those with persistent AF, as reported in the most recent and highest quality studies 1.

Procedure Overview

The procedure involves inserting thin, flexible tubes called catheters through blood vessels, typically in the groin, and guiding them to the heart. Once positioned, the catheter delivers energy (usually radiofrequency energy, cryotherapy, or laser) to specific areas of heart tissue responsible for triggering or maintaining the arrhythmia. This energy destroys small portions of tissue, creating electrical barriers that prevent abnormal signals from spreading.

Key Steps and Techniques

The technique of ablation has continued to evolve, with current approaches avoiding delivering radiofrequency energy within the pulmonary veins (PV) and instead targeting areas outside the veins to isolate the ostia from the remainder of the left atrial conducting tissue 1. Advances involving isolation of the PV at the antrum using a circular mapping catheter, guided by intracardiac echocardiography, have reportedly yielded approximately 80% freedom of recurrent AF or atrial flutter after the first 2 months in patients with paroxysmal AF 1.

Success Rates and Outcomes

The accumulated experience involves nearly 4000 patients, with approximately 90% success in cases of paroxysmal AF and 80% in cases of persistent AF 1. Restoration of sinus rhythm after catheter ablation for AF significantly improved left ventricular function, exercise capacity, symptoms, and quality of life (usually within the first 3 to 6 months), even in the presence of concurrent heart disease and when ventricular rate control was adequate before ablation 1.

Complications and Risks

Complications of catheter ablation include the adverse events associated with any cardiac catheterization procedure, with major complications reported in about 6% of procedures, including PV stenosis, thromboembolism, atrioesophageal fistula, and left atrial flutter 1. However, the incidence of these complications has dramatically decreased as a result of changes in technique.

Recovery and Follow-up

Patients usually stay in the hospital overnight for monitoring, and recovery involves avoiding strenuous activities for about a week. Patients often continue taking blood thinners like warfarin, apixaban, or rivaroxaban for at least a few months afterward 1.

From the Research

Cardiac Ablation for Atrial Fibrillation

• Cardiac ablation for atrial fibrillation (AF) is a procedure that aims to restore a normal heart rhythm by destroying the abnormal electrical pathways in the heart that are causing the arrhythmia 2.
• The procedure typically involves the use of catheters to deliver energy to the affected areas of the heart, such as the pulmonary veins, to isolate them and prevent abnormal electrical signals from entering the heart 2.
• There are different types of ablation techniques, including point-by-point radiofrequency ablation and cryoballoon ablation, which are used to achieve pulmonary vein isolation (PVI) 2.
• Additional atrial ablation can be performed in patients with persistent AF, but its benefits are largely unproven 2.

Indications for Cardiac Ablation

• Current guidelines recommend cardiac ablation for symptomatic patients with paroxysmal or persistent AF who are refractory or intolerant to antiarrhythmic drugs 2.
• The procedure may also be considered as a first-line approach in selected asymptomatic patients 2.
• Cardiac ablation has been shown to improve outcomes in patients with AF and heart failure, including reducing mortality and hospitalization for worsening heart failure 3.

Procedure Details

• The procedure is typically performed under sedation or general anesthesia, and involves the insertion of catheters through a vein in the leg and guided to the heart using imaging techniques such as fluoroscopy or intracardiac echocardiography 4, 5.
• The catheters are used to deliver energy to the affected areas of the heart, such as the pulmonary veins, to isolate them and prevent abnormal electrical signals from entering the heart 4, 5.
• The procedure can take several hours to complete, and patients are typically monitored overnight in the hospital after the procedure 4, 5.

Outcomes and Benefits

• Cardiac ablation has been shown to be effective in improving rhythm control and reducing symptoms in patients with AF 4, 2.
• The procedure has also been shown to reduce mortality and hospitalization for worsening heart failure in patients with AF and heart failure 3.
• However, the procedure is not without risks, and complications can include bleeding, infection, and damage to the heart or surrounding tissues 4, 5.