A 27-year-old man comes to the office due to syncope. Two days ago, the patient was sitting at his computer at work and then suddenly awakened lying on the ground. His coworkers saw him collapse to the floor, jerk a few times, and become still. The patient was unconscious for 1-2 minutes. He was not lethargic or confused after the episode and did not experience chest pain or shortness of breath. The patient has had two similar episodes in the last year but did not seek medical attention. He has become concerned following this third episode. He has no medical history and takes no medications. Temperature is 36.7 C (98.1 F), blood pressure is 120/60 mm Hg, pulse is 72/min, and respirations are 16/min. Pulse oximetry is 100% on room air. The patient is awake, alert, and oriented, with normal speech. He has a small occipital hematoma. Oropharyngeal examination is normal. The pupils are equal and reactive to light. Heart and lung examinations are normal. Strength is 5/5 in the upper and lower extremities, and gait is normal. ECG is normal. What is the best next step in management of this patient?
Clues to etiology of syncope | ||
Reflex syncope | Vasovagal |
|
Situational |
| |
Carotid hypersensitivity |
| |
Orthostatic syncope | Medications |
|
Hypovolemia |
| |
Autonomic dysfunction |
| |
Cardiac syncope | LV outflow obstruction |
|
Ventricular tachycardia |
| |
Conduction impairment* |
| |
*Sick sinus syndrome or advanced atrioventricular block. DM = diabetes mellitus; HD = heart disease; LV = left ventricular. | ||
This patient's sudden, brief (eg, 1-2 min) episode of loss of consciousness (LOC) and postural tone, followed by rapid recovery, is consistent with syncope. Syncope occurs due to global hypoperfusion of the brain and can have many causes. In most cases, syncope is benign and self-limiting; however, it can be the initial manifestation of a life-threatening disease process (eg, cardiac syncope).
A detailed initial evaluation can provide several clues to the underlying etiology. This patient's syncopal episode had no obvious trigger or prodrome to implicate reflex syncope; it also did not occur with position change (ie, standing from a seated position) to suggest orthostatic syncope. Instead, the syncopal episode occurred with the patient at rest and without warning symptoms. This presentation raises concern for a cardiac etiology, specifically an arrhythmic etiology, and should prompt further cardiac evaluation (Choice D).
Continuous ECG monitoring can evaluate for transient arrhythmia (eg, ventricular tachycardia) that may not be detected on initial ECG. In relatively young patients (eg, age <40) without structural heart disease, ambulatory ECG monitoring (eg, Holter monitor, insertable cardiac monitor) is usually appropriate. In contrast, patients likely need hospital admission for closer monitoring and expedited cardiac evaluation when they are older, have underlying structural heart disease (eg, prior myocardial infarction), or have an abnormal ECG.
(Choice B) CT angiography of the chest can evaluate for pulmonary embolism (PE), which sometimes presents with syncope. However, other symptoms (eg, chest pain, dyspnea) or signs (eg, hypoxemia, tachycardia) are usually present, and PE is unlikely to account for recurrent episodes of syncope.
(Choice C) Seizure activity (diagnosed on electroencephalography) can cause LOC with jerking movements; however, other suggestive features (eg, prodromal aura, postictal period) are typically present. Muscle jerks can occur in all types of syncope because sudden cerebral hypoperfusion often causes brief myoclonus.
(Choice E) Noncontrast CT scan of the head helps rule out trauma-induced intracranial injury (eg, hemorrhage). It is not indicated in this patient who experienced a relatively low-impact mechanism of injury and has no abnormal neurologic symptoms or findings 2 days after the incident.
Educational objective:
Patients with syncope not clearly attributable to a benign etiology (eg, reflex or orthostatic syncope) should undergo further cardiac workup (eg, ambulatory ECG) to determine whether a cardiac etiology is present. Syncope that occurs while supine or sitting, at rest, and without warning symptoms suggests an arrhythmic etiology.