In the JournalsPerspective

ACC/AHA/HRS guideline provides recommendations for diagnosis, prognosis for syncope

The American College of Cardiology, the American Heart Association and Heart Rhythm Society published guidelines for the assessment and treatment of patients with syncope.

Syncope affects up to 41% of the population, and recurrent syncope occurs in 13.5% of patients, according to the guidelines. In addition, women have a higher prevalence of syncope, and older patients face a higher risk for hospitalization and death caused by syncope.

“The purpose of this ACC/AHA/HRS guideline is to provide contemporary, accessible and succinct guidance on the management of adult and pediatric patients with suspected syncope,” Win-Kuang Shen, MD, professor of medicine at Mayo Clinic in Phoenix and chair of the writing committee, and colleagues wrote.

Syncope from heart conditions

Some characteristics associated with cardiac-related syncope include age older than 60 years, male sex, previous arrhythmias, presence of ischemic heart disease, reduced ventricular function, structural heart disease and presence of known congenital heart disease, according to the panel.

Class I recommendations include performing a detailed history and physical exam on patients with syncope, including a resting 12-lead ECG. An evaluation for the cause of syncope and short- and long-term morbidity and mortality risk is also recommended.

Short-term risk factors for patients with syncope comprise of cerebrovascular disease, structural heart disease, men who are older than 60 years, HF and family history of sudden cardiac death. Diabetes, cancer, ventricular arrhythmias and a high CHADS-2 are some long-term risk factors, according to the document.
After initial evaluation, a class I recommendation suggests, hospital evaluation and treatment for those with syncope that may have been caused by a serious medical condition, such as ventricular tachycardia, supraventricular tachycardia, third-degree heart block, acute HF, pacemaker malfunction and bradycardia.

Regular, comprehensive laboratory testing is not beneficial in evaluating patients. Unless the syncope is caused by a cardiac condition, routine cardiac imaging is also not useful.

Use of exercise stress testing to determine the cause of syncope in patients who experience symptoms during exertion was given a class IIa recommendation.

Imaging recommendations

Cardiac monitoring is recommended in patients depending on the nature and frequency of syncope events, supported by class I evidence. Whether external or implantable cardiac monitors should be used is to be determined by the physician.

“Detection with short-term monitoring techniques is often unsuccessful, and as a result, patients may see several different specialists and undergo multiple tests without receiving a conclusive diagnosis,” David Benditt, MD, professor of medicine and co-director of the Cardiac Arrhythmia Center at the University of Minnesota in Minneapolis, said in a press release issued by Medtronic. “When the cause of syncope is unclear, continuous long-term cardiac monitoring has become the standard of care, particularly in early stages of evaluation.”

If there are no focal neurological findings that confirm the need for further evaluation, then routine evaluation should not include carotid artery imaging, according to the guidelines.

Vasovagal syncope is the most common type of reflex syncope, and physicians should educate patients on the diagnosis and prognosis of this condition. Patients with recurring vasovagal syncope and prolonged spontaneous pauses who are 40 years or older may benefit from dual-chamber pacing, the authors wrote in a class IIb recommendation. In pediatric patients, beta-blockers are not beneficial, according to the authors.

Patients with syncope caused by acute dehydration should receive fluid resuscitation by IV or oral bolus, according to Class I recommendations. Class IIa evidence suggests that reducing or eliminating medication that’s causing hypotension may be beneficial.

Guideline-directed management and therapy are class I recommendations for patients with bradycardia, supraventricular tachycardia, ventricular arrhythmia, atrial fibrillation or structural heart conditions.

When other risk factors are not present in patients with reflex-mediated syncope and Brugada ECG pattern, an implantable cardioverter defibrillator is not recommended, according to the authors.

Beta-blocker therapy can serve as a first-line treatment for patients with suspected arrhythmic syncope and long-QT syndrome. If they are intolerant to this therapy or are currently utilizing beta-blockers, an ICD may be practical, per class IIa recommendations.

An electrophysiological study is acceptable for patients with cardiac sarcoidosis and syncope caused by arrhythmia, according to Class IIa recommendations.

Class I recommendations suggest CV assessment for athletes with syncope before they return to competitive sports. Patients should not participate in competitive sports if syncope is caused by catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy or long QT syndrome. – by Darlene Dobkowski

Disclosure : Benditt reports consulting for Medtronic and St. Jude Medical. Shen reports no relevant financial disclosures. Please see the full guideline for the other committee members’ relevant financial disclosures.

The American College of Cardiology, the American Heart Association and Heart Rhythm Society published guidelines for the assessment and treatment of patients with syncope.

Syncope affects up to 41% of the population, and recurrent syncope occurs in 13.5% of patients, according to the guidelines. In addition, women have a higher prevalence of syncope, and older patients face a higher risk for hospitalization and death caused by syncope.

“The purpose of this ACC/AHA/HRS guideline is to provide contemporary, accessible and succinct guidance on the management of adult and pediatric patients with suspected syncope,” Win-Kuang Shen, MD, professor of medicine at Mayo Clinic in Phoenix and chair of the writing committee, and colleagues wrote.

Syncope from heart conditions

Some characteristics associated with cardiac-related syncope include age older than 60 years, male sex, previous arrhythmias, presence of ischemic heart disease, reduced ventricular function, structural heart disease and presence of known congenital heart disease, according to the panel.

Class I recommendations include performing a detailed history and physical exam on patients with syncope, including a resting 12-lead ECG. An evaluation for the cause of syncope and short- and long-term morbidity and mortality risk is also recommended.

Short-term risk factors for patients with syncope comprise of cerebrovascular disease, structural heart disease, men who are older than 60 years, HF and family history of sudden cardiac death. Diabetes, cancer, ventricular arrhythmias and a high CHADS-2 are some long-term risk factors, according to the document.
After initial evaluation, a class I recommendation suggests, hospital evaluation and treatment for those with syncope that may have been caused by a serious medical condition, such as ventricular tachycardia, supraventricular tachycardia, third-degree heart block, acute HF, pacemaker malfunction and bradycardia.

Regular, comprehensive laboratory testing is not beneficial in evaluating patients. Unless the syncope is caused by a cardiac condition, routine cardiac imaging is also not useful.

Use of exercise stress testing to determine the cause of syncope in patients who experience symptoms during exertion was given a class IIa recommendation.

Imaging recommendations

Cardiac monitoring is recommended in patients depending on the nature and frequency of syncope events, supported by class I evidence. Whether external or implantable cardiac monitors should be used is to be determined by the physician.

“Detection with short-term monitoring techniques is often unsuccessful, and as a result, patients may see several different specialists and undergo multiple tests without receiving a conclusive diagnosis,” David Benditt, MD, professor of medicine and co-director of the Cardiac Arrhythmia Center at the University of Minnesota in Minneapolis, said in a press release issued by Medtronic. “When the cause of syncope is unclear, continuous long-term cardiac monitoring has become the standard of care, particularly in early stages of evaluation.”

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If there are no focal neurological findings that confirm the need for further evaluation, then routine evaluation should not include carotid artery imaging, according to the guidelines.

Vasovagal syncope is the most common type of reflex syncope, and physicians should educate patients on the diagnosis and prognosis of this condition. Patients with recurring vasovagal syncope and prolonged spontaneous pauses who are 40 years or older may benefit from dual-chamber pacing, the authors wrote in a class IIb recommendation. In pediatric patients, beta-blockers are not beneficial, according to the authors.

Patients with syncope caused by acute dehydration should receive fluid resuscitation by IV or oral bolus, according to Class I recommendations. Class IIa evidence suggests that reducing or eliminating medication that’s causing hypotension may be beneficial.

Guideline-directed management and therapy are class I recommendations for patients with bradycardia, supraventricular tachycardia, ventricular arrhythmia, atrial fibrillation or structural heart conditions.

When other risk factors are not present in patients with reflex-mediated syncope and Brugada ECG pattern, an implantable cardioverter defibrillator is not recommended, according to the authors.

Beta-blocker therapy can serve as a first-line treatment for patients with suspected arrhythmic syncope and long-QT syndrome. If they are intolerant to this therapy or are currently utilizing beta-blockers, an ICD may be practical, per class IIa recommendations.

An electrophysiological study is acceptable for patients with cardiac sarcoidosis and syncope caused by arrhythmia, according to Class IIa recommendations.

Class I recommendations suggest CV assessment for athletes with syncope before they return to competitive sports. Patients should not participate in competitive sports if syncope is caused by catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy or long QT syndrome. – by Darlene Dobkowski

Disclosure : Benditt reports consulting for Medtronic and St. Jude Medical. Shen reports no relevant financial disclosures. Please see the full guideline for the other committee members’ relevant financial disclosures.

    Perspective
    • This is a very comprehensive document that ACC/AHA/HRS put together. There’s a really nice table where the definitions of many of the relevant terms that are used. This can be very useful for the users that are not usually acquainted with managing patients with syncope. The document provided very nice and clear definitions.

      The document also presents a lot of very nice figures and algorithms that are very important for the management of patients with syncope. One of the major recommendations is to do risk assessment based on a number of recommended risk scores that are summarized in the document. This is always important, because one of the issues with syncope is that people don’t know whether a patient presenting with syncope in the office or [ED] is a high risk or a low risk patient, and we need to know if these patients need to be admitted for further investigation. This document offers a very comprehensive and straightforward way of tackling that.

      Part of the lack of success we’ve had with syncope is that people usually practice in a defensive way. A patient who comes with syncope to the [ED] gets the million-dollar workup: ECG, CT scan and a bunch of tests that are normally very low yield, unnecessary and expensive. This document provides very clear indications for each one of those tests, when and when they should not be done in a patient presenting with syncope.

      Overall, the document’s major contribution is a very simple algorithmic approach to the patient with syncope.

      We always wish that everything that we write gets implemented immediately, but we know that’s not the case. It’s not even the case with large clinical trials. It takes anywhere between 2 to 5 years to get people to prescribe whatever the new data show, but this document adds a lot and makes it really easy for people that are dealing with syncope.

      The writing committee consisted of not only people that are experts in syncope, but general cardiologists, the electrophysiologists and more importantly, people from the [ED] providing a lot of influence. This document now is probably the best document that can be used by anyone that sees a patient with syncope in the community. Hopefully this will be implemented within the next year or so. The figures and algorithms that make it very easy stepwise will help people implement this relatively soon.

      We still have a lot of knowledge gaps. We know when patients have reflex vasovagal syncope, a high-risk condition. We can identify those pretty easily. The challenges are with people that are at intermediate risk. You’re not sure if you should admit them or send them home, or of what amount of monitoring you need. We need some information on which patients benefit from newer technologies such as implantable cardiac monitors.

      The other knowledge gap that we have is implementing appropriately all this information to a population with syncope and reducing overall the risk for repeated episodes of syncope. Again, we’ve had made significant strides in advancements in our understanding of syncope, but there’s still maybe 10% to 20% of the population that come with recurring syncope for which we can’t find a cause, so we need to understand that population. There are a number of clinical trials that are ongoing that hopefully in the next 3 to 5 years will provide this information.

      This is a comprehensive, clear document that will be highly adopted by clinicians that see patients with syncope. Syncope is not exclusive of a cardiologist or the internist. The [general practitioner], [ED] physicians, pediatricians, everybody sees patients with syncope, and they’re always very challenging. This document provides really a very comprehensive stepwise, easy approach that was a very large and comprehensive review of all the evidence available. The writing committee did a fantastic job, and this document is going to be widely used and hopefully implemented in a timely fashion.

      • Carlos A. Morillo, MD, FRCPC, FACC, FHRS, FESC
      • Professor, Department of Cardiac Sciences
        Cumming School of Medicine, University of Calgary
        Section Chief, Division of Cardiology
        Libin Cardiovascular Institute, University of Calgary
        Zone Head, Cardiology, Calgary and Southeastern Alberta Region
        Alberta Health Services
    • Disclosures: Morillo reports consulting for Boston Scientific, Medtronic and St. Jude Medical.