Early approaches to non-pharmacologic therapy for atrial fibrillation mainly addressed rate control. These approaches include modification of the atrioventricular node, or more commonly, atrioventricular node ablation with implantation of a permanent pacemaker.

Newer approaches have attempted to increase the probability of maintaining sinus rhythm. These include adjunctive pacing, the use of implantable defibrillators, surgical procedures, and catheter ablation.

Traditional atrial overdrive pacing may decrease the likelihood of atrial fibrillation, but results of studies have been mixed. Although some studies suggest a reduction of up to 60%, others show no effect.

Implantable combined atrial/ventricular defibrillators allow for dual-chamber pacing. They provide therapy for both ventricular and atrial tachyarrhythmia through anti-tachycardia pacing and both low- and high-energy shocks.

In most cases, atrial fibrillation thresholds are reasonable with the lead configurations in standard implantable atrial defibrillators. The energy required to terminate defibrillation is in the range of 4 to 7 joules. However, this amount of energy can still cause a considerable amount of pain. For this reason, researchers hoped novel pacing therapies could further decrease episodes of atrial fibrillation.

To test this, investigators studied the effects of a Jewel AF implantable defibrillator in 537 patients with ventricular arrhythmia and documented history of atrial tachyarrhythmias in most cases. This device uses 3 different overdrive atrial pacing methods and discriminates between atrial tachycardia and atrial fibrillation based on length and regularity of cycle. Investigators found that atrial pacing terminated almost half (48%) of all episodes of atrial tachycardia and atrial fibrillation. Unfortunately, many patients continued to require shocks.

Another recent trial of the Jewel AF device showed a decrease in atrial fibrillation burden from 53 hours per month (pacing therapies off) to 6.2 hours per month (pacing therapies on). However, the benefit accrued to just about 25% of patients, with most of the rest showing relatively little change. The median change was less than 1 hour per month.

These trials show that the application of pacing algorithms work to a modest degree, but that many patients continue to have episodes.

Curing atrial fibrillation would be preferable to treatment that simply manages symptoms. For that reason, there have been many studies evaluating ablation strategies, mostly occurring in the pulmonary veins.

The results of ablation procedures are quite successful, both for improving clinical outcomes and quality of life. For isolation procedures, the cure rate is about 70% to 80% in some series. Variables such as age, gender, left ventricular ejection fraction, or duration of atrial fibrillation do not appear to have an effect on the success of the procedure.

Downsides of ablation procedures include cardiac perforation, pulmonary vein dissection, vascular damage and stroke, among others. The most worrisome complication is pulmonary vein stenosis. Severe stenosis occurs in far less than 5% of cases, but up to 25% of patients have it to some degree. Symptoms can include severe dyspnea and coughing up blood from the respiratory tract.

Furthermore, this therapy appears to be somewhat more effective in patients with paroxysmal episodes of atrial fibrillation as opposed to persistent or chronic atrial fibrillation. It would be desirable to have ablation procedures also applicable to persistent and chronic atrial fibrillation.

In the future, it is likely that both surgical and catheter ablation approaches will develop not just for treatment of paroxysmal cases, but also for persistent and even chronic atrial fibrillation. For now, the front line treatment for all patients is still pharmacologic therapy.