New Guidelines for Managing Adult Patients with SVT Released

September 25, 2015

MADISON, WI — The American College of Cardiology, American Heart Association, and the Heart Rhythm Society (ACC/AHA/HRS) have published new guidelines for the management of patients with supraventricular tachycardia (SVT), a document that has been 1 year in the works[1].

"Unlike a guideline update, this is a new set of 'from-the-ground-up' guidelines," Dr Richard Page (University of Wisconsin School of Medicine and Public Health, Madison), chair of the ACC/AHA/HRS writing committee, told heartwire from Medscape. "It is designed to specifically address supraventricular tachycardia, among things. While supraventricular tachycardia could theoretically include atrial fibrillation, most of us don't include atrial fibrillation with SVT, and these guidelines specifically don't include the management of atrial fibrillation."

SVT encompasses tachycardia that results from atrial and/or ventricular rates greater than 100 beats per minute. These include sinus tachycardia, atrial tachycardia (AT), junctional tachycardia, atrioventricular nodal reentry tachycardia (AVNRT), and other accessory-pathway–mediated reentrant tachycardias.

In the general population, the prevalence of SVT is 2.25 individuals per 1000 persons, and the incidence of paroxysmal SVT, after adjustment for age and sex in the US population, is estimated to be 36 cases per 100,000 persons per year. Each year in the US, there are 89,000 new cases and 570,000 individuals with paroxysmal SVT.

The new ACC/AHA/HRS recommendations are published September 23, 2015 in Circulation. They are co-published in the Journal of the American College of Cardiology and Heart Rhythm Journal.

Acute and Long-term Management

With the new guidelines, the writing committee provides recommendations for the acute management of SVT, noting that patients with SVT account for approximately 50,000 emergency visits each year. Vagal maneuvers are recommended for acute treatment, as is adenosine, in patients with regular SVT. Synchronized cardioversion is also recommended in hemodynamically unstable SVT patients or in stable patients where drug therapy is ineffective or contraindicated.

In addition, the guidelines provide recommendations for the ongoing management of SVT patients, including, among other recommendations, the use of oral beta-blockers, diltiazem, or verapamil in symptomatic SVT without ventricular preexcitation during sinus rhythm. An electrophysiology study with the option of ablation is "useful" for the diagnosis and potential treatment of SVT, the guidelines note.

The proposed treatment algorithms within the clinical guidelines are designed to foster shared decision making, one that includes physicians, patients, and their families. To heartwire , Page said ablation remains an option for symptomatic SVT patients and an option for first-line therapy in many cases based on patient preference.

One agent that has not previously been included in the SVT guidelines is ivabradine (Corlanor, Amgen), a drug that is approved by the US Food and Drug Administration (FDA) to prevent the worsening of heart failure in stable patients with a heart rate of >70 per minute on maximally tolerated beta-blockers. Although the use is off-label, the treatment guidelines state ivabradine is a reasonable treatment option for the ongoing management of patients with symptomatic inappropriate sinus tachycardia (class IIa, level of evidence B-R).

"Ivabradine was recently approved for the sinus tachycardia that can accompany heart failure, but it has unique properties, in limited studies, for inappropriate sinus tachycardia, a problem for which we have never had satisfactory therapeutic options," Page told heartwire .

As part of an extensive evidence review, the ACC/AHA/HRS experts also addressed treatment options for patients with Wolfe-Parkinson-White (WPW) syndrome and patients with asymptomatic ventricular preexcitation (WPW pattern on ECG). Page noted that in patients who lose preexcitation with exercise testing, it might be useful to identify patients at low risk of rapid conduction over the accessory pathway as WPW can be a life-threatening condition.

They state that it is "reasonable" (class IIa recommendation) for an EP study in asymptomatic patients with preexcitation in order to risk-stratify these patients for arrhythmic events. Catheter ablation is also a reasonable option (class IIa) if the EP study identifies patients at high risk for arrhythmic events or in individuals with specific types of jobs, such as airline pilots. "Likewise, the guideline also says that it's reasonable to simply observe," said Page.

The writing committee also factored in quality-of-life considerations, noting that patients with SVT may experience recurring symptoms that negatively affect their day-to-day activities. Light-headedness and syncope, brought on by tachycardia, can get in the way of driving, for example. In addition to quality of life, the ACC/AHA/HRS recommendations also address the cost-effectiveness of various therapies, including the comparisons of medical therapy vs catheter ablation.

Page said while the experts considered quality of life, cost-effectiveness, and shared decision making in the management of patients with SVT, there were not enough data to make any specific recommendations in the new document.

Like previous guidelines, the strength of the recommendations range from class I, a strong recommendation that is clinically indicated/useful/beneficial or should be performed, to class III, which means the therapy provides no benefit or is potentially harmful or associated with excess morbidity/mortality.

However, the new SVT guidelines introduce a modified method of assessing the quality of evidence, with the evidence ranging from level A, meaning high-quality evidence from more than one randomized clinical trial, to level C, which includes limited data from nonrandomized observational or registry studies (level C-LD) or expert opinion based on clinical experience (level C-EO). Level B evidence includes data from randomized trials (level B-R) and nonrandomized trials (level B-NR).

Page reports no relevant financial relationships. Disclosures of the ACC/AHA/HRS writing committee are available in the published report.


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