NEW YORK - Catheter ablation is favored for the management of most forms of supraventricular tachycardia (SVT) in adults, according to revised guidelines from the American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS).
SVT affects 2.25 in 1000 individuals in the general population, with about 89,000 new cases of paroxysmal SVT (PSVT) per year. Women are twice as likely as men and individuals older than 65 are more than five times as likely as younger people to develop PSVT.
Included are recommendations for managing sinus tachyarrhythmias, nonsinus focal atrial tachycardia and multifocal atrial tachycardia (MAT), atrioventricular nodal reentrant tachycardia (AVNRT), manifest and concealed accessory pathways, atrial flutter, and junctional tachycardia.
"Despite a 12-year gap in the update for these guidelines, there have been very few advances in antiarrhythmic drug therapy to offer patients with SVT," Dr. Gregory F. Michaud, director of the Center for Advanced Management of Atrial Fibrillation at Brigham and Women's Hospital in Boston, said by email.
"Catheter ablation has taken a stronger foothold in the chronic treatment of SVT and as such many physicians and patients are opting for invasive therapy earlier in the course of therapy," said Dr. Michaud, who wasn't involved in the guidelines.
The guidelines recommend vagal maneuvers, various drugs, and/or cardioversion as acute treatments, depending on the specific cause of SVT.
For most forms of symptomatic SVT, including those of unknown mechanism, the guidelines recommend electrophysiological (EP) studies and catheter ablation as definitive treatment for patients willing to undergo them, especially if medical therapy is ineffective.
Cardiac mapping is performed during EP studies to identify the site of origin of the arrhythmia or areas of critical conduction to allow targeting of ablation.
"One exception is inappropriate sinus tachycardia (IST) for which a more effective drug, ivabradine, is now available in the United States," Dr. Michaud said. "Catheter ablation is generally ineffective for IST patients."
Besides evaluation and treatment of possible reversible causes of IST, the guidelines recommend ivabradine, beta blockers, or their combination.
"SVT is generally not a life-threatening condition and treatment is based on eliminating symptoms and improving patient quality of life," Dr. Michaud explained. "However, physicians should be aware of three conditions associated with SVT that may be serious. First, sudden death is associated with the WPW (Wolff-Parkinson-White) syndrome and these patients, even if asymptomatic, should be referred to a cardiac electrophysiologist to consider management options."
He continued, "Second, SVT can cause cardiomyopathy and heart failure when incessant, even if the patient is asymptomatic. These patients should also be referred to a cardiac electrophysiologist to consider definitive therapy.
Dr. Michaud added, "Putting aside cost as an issue, there is significant regional variability in the accessibility of electrophysiologists or cardiologists with arrhythmia expertise. In my area, for instance, electrophysiologists are plentiful, and patients with SVT are often sent to us directly for further evaluation and treatment. Furthermore, training in arrhythmia management has become the purview of clinical cardiac electrophysiology, and many recently trained cardiologists are not as comfortable as their predecessors in managing patients with SVT."
Dr. Richard L. Page and Dr. Jose A. Joglar, chair and vice chair of the writing committee, did not respond to a request for comments.