Practice Guidelines

Syncope Evaluation and Treatment Guidelines from ACC, AHA, and HRS


Am Fam Physician. 2018 Apr 1;97(7):478-479.

Key Points for Practice

• Resting 12-lead electrocardiography can be beneficial in determining the cause of syncope in the initial evaluation.

• Laboratory testing can be ordered based on the history and examination to aid in diagnosis of syncope, but routine comprehensive testing in all patients with syncope is not useful.

• Transthoracic echocardiography may be beneficial if there is suspicion for structural heart disease.

From the AFP Editors

Although the incidence of syncope, which has multiple causes and presentations, varies by population, a prevalence as high as 41% has been reported. The American College of Cardiology (ACC), American Heart Association (AHA), and Heart Rhythm Society (HRS) have released guidelines to assist physicians in evaluating and treating syncope.

History and Physical Examination

A history should be taken and physical examination performed in persons who present with syncope. The goal of the history should be to determine prognosis, diagnosis, reversible factors, comorbidities, medication use, and individual and family needs. Historically, factors associated with a cardiac cause of syncope include age older than 60 years, male sex, ischemic heart disease, structural heart disease, previous arrhythmias, reduced ventricular function, brief prodrome, sudden loss of consciousness, syncope while supine or during exertion, experiencing only one or two syncope episodes, abnormal findings on cardiac examination, family history of inheritable conditions or sudden cardiac death before 50 years of age, and congenital heart disease. Factors associated with a noncardiac cause include younger age, absence of cardiac disease, syncope episodes only while standing, positional change (e.g., from sitting to standing), prodrome, triggers (e.g., dehydration, coughing), and recurrence or prolonged history of syncope.

Orthostatic blood pressure should be measured and heart changes should be evaluated when the patient is lying, sitting, immediately standing, and upright (after three minutes). Murmurs, gallops, and rubs should be identified; heart rate and rhythm should be assessed; and a neurologic examination should be performed.


Based on moderate-quality evidence from nonrandomized studies, resting 12-lead electrocardiography (ECG) can be beneficial in patients initially presenting with syncope by providing information on possible causes; however, findings on ECG have not been shown to significantly affect treatment.

Risk Assessment

Risk stratifying patients who present with syncope can guide treatment and avoid morbidity

Author disclosure: No relevant financial affiliations.

Coverage of guidelines from other organizations does not imply endorsement by AFP or the AAFP.

This series is coordinated by Sumi Sexton, MD, Editor-in-Chief.

A collection of Practice Guidelines published in AFP is available at



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