CLINICAL PRESENTATION

...... History

A comprehensive history is critical and may identify the

etiology in up to 40% of cases. It is very important to

clarify all of the events immediately preceding, during, and

after the episode. Interview all family members and emer ­

gency medical service personnel present during the event.

Inquire about any concerning prodromal symptoms

including headache (ie, subarachnoid hemorrhage [SAH] ),

chest pain (ie, myocardial infarction [MI] , aortic dissec ­

tion, PE), and abdominal or back pain (ie, ruptured

abdominal aortic aneurysm [AAA] or ectopic pregnancy).

Obtain a detailed past medical history and review all current medications. Patients with significant cardiac histories

are at higher risk of arrhythmia, whereas elderly patients

on multiple medications are predisposed to orthostatic

syncope.

Antecedent dizziness, nausea, and diaphoresis or

symptoms occurring after moving from a recumbent or

sitting to upright position suggest a benign vasovagal

or orthostatic episode respectively. Syncope that occurs

either suddenly without prodrome or with physical exertion suggests arrhythmia or structural heart disease (aortic stenosis, hypertrophic cardiomyopathy). A prolonged

recovery period after syncope indicates a cerebrovascular

etiology (stroke, seizure, SAH), as classically all patients

should regain consciousness within several seconds of the

event.

...... Physical Examination

Always obtain triage vital signs and repeat when abnormal.

Obtain blood pressure (BP) measurements in both arms,

looking for unequal pressures suggestive of aortic dissec ­

tion. Consider orthostatic vitals, comparing recumbent

SYNCOPE

and standing vital signs. Significant BP findings include a

drop in systolic BP by :2:20 mmHg or an absolute value ::;90

mmHg when standing. Orthostasis suggests volume depletion or medication side effects. The cardiovascular exam

should include a detailed auscultation of the heart, listening for arrhythmias or any murmurs suggestive of underlying structural heart disease. A detailed neurologic exam

should identify any focal neurologic deficits. Perform a

rectal exam with stool guaiac analysis to assess for gastrointestinal ( GI) blood loss.

DIAGNOSTIC STUDIES

...... Laboratory

Routine laboratory evaluation is useful only when indicated by the history and physical exam. Obtain a rapid

bedside glucose in all patients with an altered sensorium.

Beside urine pregnancy testing is important for all females

of reproductive age. Check a complete blood count in all

patients with a history of bleeding or a positive stool

guaiac. Order a basic metabolic panel with any concern for

cardiac dysrhythmia secondary to significant electrolyte

abnormalities. Finally, check cardiac markers in patients

with antecedent chest pain or shortness of breath.

...... Electrocardiogram

Although the yield is relatively low ( <5%) for discerning

the source of a syncopal event, obtain an electrocardiogram (ECG) in all patients to rapidly identify any emergent

life threats. Concerning abnormalities on ECG include the

following:

1. Signs of ischemia or strain (Q waves, T wave, and

ST-segment changes, right bundle branch block)

2. Signs of conduction anomalies (prolonged QRS or QT

intervals, atrioventricular blocks, sinus pauses/arrest)

3. Signs of ectopy or arrhythmia (frequent premature

ventricular contractions, pre-excitation, Brugada crite ­

ria, significant bradycardia <50 bpm) (Figure 19-1)

4. Signs of cardiomyopathy (left ventricular hypertrophy

with or without strain pattern)