What Is the Most Cost- Effective Evaluation for a First Syncopal Episode?

Case

A 71-year-old woman is admitted after losing consciousness and falling at home. Her history is significant for hypertension, bilateral internal carotid artery stenoses, chronic kidney disease, and diabetes. Resting vital signs are normal. Cardiac, pulmonary, and neurologic exams are unremarkable, as is an electrocardiogram (ECG). She was noted to have a small scalp laceration. Noncontrast CT of the head demonstrates a small occipital subdural bleed thought to be a result of her fall.

Syncope accounts for 1% to 2% of ED visits in the U.S. annually. The primary E&M objective is identifying patients at increased risk of death due to associated conditions (e.g., heart disease, myocardial ischemia).

Syncope accounts for 1% to 2% of ED visits in the U.S. annually. The primary E&M objective is identifying patients at increased risk of death due to associated conditions (e.g., heart disease, myocardial ischemia).

What is the most cost-effective evaluation for this patient admitted with suspected first syncopal episode?

Overview

Syncope is defined as sudden, self-terminating loss of consciousness. The final common pathway of all causes of syncope is global cerebral hypoperfusion—specifically, hypoperfusion of the reticular activating system. The differential diagnosis of syncopal loss of consciousness includes neurally mediated (e.g., vasovagal) syncope, orthostatic hypotension, cardiac arrhythmias, structural heart disease, and cerebrovascular disease.

Among young, otherwise healthy people, neurally mediated syncope, which has a relatively benign prognosis, is by far the most common etiology, while in older patients, primary cardiac causes are more common. Nonsyncopal mechanisms, such as seizure and hypoglycemia, should also be considered in the differential diagnosis of transient loss of consciousness (see Table 1, p. 19).1

Syncope is a common problem, accounting for 1% to 2% of ED visits in the U.S.2 The primary objective for evaluation is identification of individuals at increased risk of death due to associated conditions, especially cardiac conditions such as structural heart disease; myocardial ischemia and infarction (MI); Wolff-Parkinson-White, Brugada, or long QT syndromes; and polymorphic ventricular tachycardia.3 True syncope can be associated with other concerning causes, such as aortic stenosis, aortic dissection, and massive pulmonary embolus, as well as arrhythmias from underlying cardiac disease.4

KEY Points

  • An estimated 86% of individuals seen in the ED after a syncopal episode are admitted to the hospital.
  • Among diagnostic tests, orthostatic blood pressure measurement (performed in about one-third of cases) is both the highest-yield test and the least expensive.
  • Initial evaluation of syncope should include medical history, physical examination, ECG, and postural blood-pressure testing.
  • Cardiac enzymes, electroencephalography, CT scan of the head, and carotid ultrasonography contribute to diagnosis in less than 1% of cases. Echo is helpful about 2% of cases. Even inpatient telemetry, a routine part of standard evaluation, is helpful only 5% of the time.
  • Patients can be reassured that, in the absence of underlying cardiac disease, syncope itself is not associated with increased mortality.

Additional Reading

  • Jhanjee R, Can I, Benditt DG. Syncope. Dis Mon. 2009;55(9):532-585.
  • Strickberger SA, Benson DW, Biaggioni I, et al. AHA/ACCF Scientific Statement on the evaluation of syncope: from the American Heart Association Councils on Clinical Cardiology, Cardiovascular Nursing, Cardiovascular Disease in the Young, and Stroke, and the Quality of Care and Outcomes Research Interdisciplinary Working Group; and the American College of Cardiology Foundation: in collaboration with the Heart Rhythm Society: endorsed by the American Autonomic Society. Circulation. 2006;113(2):316-327.
  • McGee S. Evidence-Based Physical Diagnosis. Saunders; 2001.
  • Linzer M, Yang EH, Estes NA 3rd, Wang P, Vorperian VR, Kapoor WN. Diagnosing syncope. Part 1: Value of history, physical examination, and electrocardiography. Clinical Efficacy Assessment Project of the American College of Physicians. Ann Intern Med. 1997;126(12):989-996.

Review of the Data

History: A detailed history and physical examination reveals the cause in 50% of syncopal episodes. Key factors include the account of third-party observers, although it is important to note that tonic-clonic movements can be associated with the global cerebral hypoperfusion of syncope as well as with seizure.4 History of dyspnea, chest pain, or palpitations argue for a primary cardiac or pulmonary cause.

About Richard Quinn

Richard Quinn is an award-winning journalist with 15 years’ experience. He has worked at the Asbury Park Press in New Jersey and The Virginian-Pilot in Norfolk, Va., and currently is managing editor for a leading commercial real estate publication. His freelance work has appeared in The Jewish State, The Hospitalist, The Rheumatologist, ACEP Now, and ENT Today. He lives in New Jersey with his wife and three cats.

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