Answers: 1. D, 2. C, 3. B
Syncope is the sudden transient loss of consciousness with a loss of postural tone. The most important defining feature being transient, in that it resolves spontaneously within a small time frame. It is a common complaint in the ED and presents at a national rate of 2.8 visits per 1000. Most cases are benign and have a very low morbidity/mortality outcome, although serious underlying disease and trauma following syncope often complicates the clinical picture.
The causes of syncope are numerous, but all causes eventually lead to a final common pathway of dysfunction of either both cerebral hemispheres or the brain stem/reticular activating system. A 35% reduction in blood flow to the CNS usually results in LOC and can be attributed to changes in CO, SVR, and/or intravascular volume. Etiologies behind these changes often define the type of syncope that occurs. With such a large differential the goal of an ED physician handling a patient with syncope is identifying those patients with serious pathology that would result in increased morbidity and mortality if left untreated. Life threatening causes of syncope that need to be identified include cardiac ischemia, dysrhythmias, cardiac valve lesions, cerebrovascular disease, metabolic and toxicologic derangements, severe hypovolemia, and anemia.
Clearly, syncope is often just a symptom of another disease and often when a patient presents following a syncopal episode they will have no other complaints. That is why a thorough HPI, PMH, and medication list must be obtained. It is invaluable in separating benign syncopal events from the more serious. Combined with a proper physical exam and a few ancillary tests including EKG a serious case of syncope will never be missed.
In our case a middle aged female with past medical hx of anemia and fibroid uterus presented with a case of apparent orthostatic syncope. The patient reported standing up from a sitting position becoming faint and loosing consciousness. Family provided details of the actual syncopal event and described the fast return to baseline. In further questioning she admits to vaginal bleeding for multiple days and feeling weak days leading up to presentation. Pertinent negatives included the patient not exerting herself before the event, she had no chest pain, SOB, and no history of cardiac arrhythmias or CHF. Also, no seizure like activity was described. The patient’s medication list showed no drugs with cardiac effects.
Physical exam also helped narrow the diagnosis. Vital signs including orthostatics were consistent with anemia or volume depletion. CV demonstrated no murmurs or thrills and lungs were clear to auscultation leading one away from a diagnosis of valvular disease, MI, of CHF that could be underlying her syncope. A thorough neuro exam helped rule out stroke and seizure.
Ancillary tests including EKG, CBC, and electrolytes helped clinch the diagnosis. With hemoglobin of 2.9, a hx of sig bleeding and syncope on standing this was most likely a case of volume depletion combined with chronic anemia leading to hypoperfusion of the CNS and syncope. The patient autocorrected the hypoperfusion on her own by losing postural tone and falling to the ground. In doing this she was able to increase venous return to the heart, increase CO, and subsequently return proper perfusion to the CNS thereby regaining consciousness and postural tone.
The first question is general epidemiology. The correct answer is D, unknown or idiopathic. Most cases of syncope in the age group are related to benign etiologies. These patients will have a completely negative ED workup and further testing to make a definitive diagnosis like a tilt table test are not within the realm of an ED workup.
The second question brings to light the problem of distinguishing syncope from a seizure which at times can be difficult. The correct answer is C. It is not uncommon for generalized tonic/clonic movements to present during syncope. It is also not completely rare to see new onset seizures in the patients in this age group. If a patient remembers feeling faint and loosing tone they could have had a “presyncopal” event or a simple/complex partial seizure among other things. If on the other hand, there is no post ictal state with loss of postural tone and a quick return to baseline status no matter what happens in between, this is most likely to be syncope and not a seizure.
The third question brings up disposition of a syncopal pt. The correct answer is B. Using the San Francisco Syncope Rule as guidelines, pts with the absence of abnormal ECG findings, SOB, Hypotension (systolic less then 90), anemia (Hematocrit less then 30%), or hx of CHF are low risk and can be followed up outpatient. Furthermore any patients with exertional syncope, chest pain, or valvular disease need hospitalization. In this question, the correct answer B whom has none of these findings. He does however qualify for carotid sinus sensitivity and carotid sinus syncope which is usually benign and can be followed up as an outpatient.
Rosen’s Emergency Medicine, seventh edition, 2010, pages 142-147, Marx
Syncope: E-Medicine. emedicine.medscape.com/article/811669
Carotid Sinus Hypersensitivity: E-Medicine. emedicine.medscape.com/article/153312
Approach to adult patient with syncope: UpToDate. www.uptodate.com
Filed under: Intern Report |