Syncope

Key considerations: Cardiac arrhythmia (VT, bradycardia, heart block), Aortic stenosis, Pulmonary embolism

Cannot miss

history: Position at time of event (standing, sitting, supine); Activity (exertional vs rest); Prodrome: lightheadedness, nausea, tunnel vision, diaphoresis (vasovagal); Witness account: seizure activity, duration of LOC; Medications: antihypertensives, diuretics, QT-prolonging drugs; Post-event confusion (suggests seizure, not syncope); exam: Orthostatic vital signs (supine → standing: positive if SBP drop ≥20 or HR rise ≥30); Cardiac: murmurs (aortic stenosis, HOCM), irregular rhythm; Neurological: focal deficits (stroke, SAH); Rectal exam if GI bleed suspected; Pregnancy test in women of reproductive age; labs: CBC (anemia, infection); BMP (electrolytes, glucose); Troponin if cardiac etiology suspected; HCG in women of reproductive age; Lactate if concern for shock; Blood glucose; imaging: CXR if cardiopulmonary cause suspected; CT head if concern for SAH or head trauma from fall; CT angiography if PE or dissection suspected; Echocardiogram if structural heart disease suspected; bedside: 12-lead ECG: arrhythmia, long QT, Brugada, WPW, heart block; Point-of-care glucose; Bedside echo if concerned for structural cause

immediate: IV access, cardiac monitor, orthostatic vitals; Assess for traumatic injuries from fall; Pregnancy test if applicable; general: Risk stratify with San Francisco Syncope Rule or Canadian Syncope Risk Score; IV fluids if orthostatic or dehydrated; Review medication list for offending agents; Telemetry monitoring if cardiac cause suspected; specific: diagnosis: Vasovagal; steps: Reassurance and education on prodromal awareness; Counter-pressure maneuvers (leg crossing, hand gripping); Avoid prolonged standing, dehydration; Follow up with PCP; diagnosis: Orthostatic; steps: IV fluid resuscitation; Review and adjust medications; Compression stockings, slow positional changes; Evaluate for autonomic neuropathy if recurrent; diagnosis: Cardiac Arrhythmia; steps: Treat underlying arrhythmia per ACLS protocols; Cardiology consult; Continuous telemetry; Consider EP study and possible ICD placement

admit: Abnormal ECG suggesting arrhythmia; Syncope with exertion; Known structural heart disease; Positive troponin; Hemodynamic instability; High-risk features on risk scoring; discharge: Classic vasovagal with clear trigger and prodrome; Normal ECG, normal labs, normal vitals; Young patient without cardiac risk factors; Reliable follow-up within 1-2 weeks; consults: Cardiology: suspected arrhythmia, structural heart disease, exertional syncope; Neurology: suspected seizure, focal neurological findings

Syncope during exertion = cardiac until proven otherwise — never discharge without cardiology evaluation
Orthostatic vitals must be measured properly: 3 minutes standing minimum before checking
Post-event confusion lasting >5 minutes suggests seizure rather than syncope
Elderly syncope: always consider GI bleed, PE, and cardiac arrhythmia even if presentation seems benign
San Francisco Syncope Rule: CHF history, Hct <30, abnormal ECG, shortness of breath, SBP <90 → admit if any positive

ESC Syncope Guidelines 2018, AHA/ACC Syncope Guidelines 2017. Last reviewed: 2024-11-01