Because we were concerned about the patient’s unexplained syncopal episode, we ordered laboratory tests, including a complete blood count (CBC), evaluation of electrolytes and glucose levels, and kidney function. In addition, we also ordered an electrocardiogram (ECG) and a noncontrast computed tomography (CT) scan of the head. All laboratory test results were within normal range. The ECG, however, demonstrated sinus bradycardia (approximately 58 beats/minute), a normal PR and QRS interval, a normal axis, and an incomplete right bundle branch block with tall, large, splayed upright T waves in the precordial leads (Figure). Based on the abnormal ECG results, we ordered serum cardiac marker studies, the values of which were all within normal range. The noncontrast CT scan of the head revealed a low-density posterior fossa mass compressing the fourth ventricle with secondary hydrocephalus.
The patient was placed with his head in an upright position and given 1 g/kg mannitol and 10 mg dexamethasone intravenously (IV). Neurosurgery services were consulted, and the patient underwent surgery the following morning. Surgery confirmed the presence of a hemangioblastoma. The hemangioblastoma was successfully excised, and the patient had an uneventful recovery. Interestingly, the significant T-wave changes in the precordial leads were no longer present postoperatively.
Discussion
Syncope and near-syncope are common reasons for ED visits. Syncope is a syndrome characterized by a transient, self-limited episode of loss of consciousness occurring as a result of a brief interruption of the oxygen supply to the brain.1 This interruption is almost always due to a transient cessation of blood flow.1 In true syncope (as opposed to seizures or hypoglycemia), the episode is characterized by a rapid onset of loss of consciousness—with or without warning symptoms.1 It is important to determine the cause of syncope, because 7% to 23% of such patients will suffer serious outcomes within 7 to 30 days of their ED visit—either within a hospital setting or at home.2
Etiology
There are many causes of syncope. In most cases, the etiology falls under one of three broad categories: neurally mediated (or reflex mediated), orthostatic hypotensive-mediated, or cardiovascular (CV)-mediated. Less common causes of syncope include cerebrovascular injury.1 The Table outlines both common and uncommon causes of syncope.
