1. What is the most important etiology to rule out?
C.L.I.P.S.
SYNCOPE (1)
Etiology
45%: Neurally mediated (carotid sinus syndrome, situational, vasovagal)
20%: Cardiogenic (arrhythmia, structural disease)
10%: Orthostatic (meds, postural tachycardia syndrome, autonomic failure, volume depletion)
Others: unexplained or other non-traumatic causes (seizure, Neurogenic, Psychogenic, intoxication, metabolic)
Diagnosis/Workup
Standardized approach: ↓ admission, costs and testing
History, history history!!! (check if really syncope, if with CV hx and for other clues re etiology; FHx of sudden death?)
The BIG THREE: Hx and PE, Orthostatic vital signs, ECG.
Orthostatic hypotension: ↓ SBP to <90mmHg, ↓ SBP by 20mmHg, ↓DBP by 10mmHg.
Labs and Imaging: only as necessary.
Risk stratification
Low risk: no admission if ALL are met
- age <50, no hx of CV dx, normal ECG, hx consistent with neurally mediated or orthostatic cause, normal cardiac exam
High risk: admission for monitoring and further work up
- everything else; including severe anemia, abnormal electrolytes, hypotension, and family hx of sudden death.
What is the most important etiology to rule out?
Cardiogenic.
Associated with increased morbidity and mortality. Mortality rate OVERALL of 8.4% in 1 year, 1/3 of cases from cardiovascular (CV) causes.
Updated 6/18 MChungtuyco

2. Common meds associated with orthostatic syncope:
C.L.I.P.S.
Common meds associated with orthostatic syncope:
Anti-arrhythmics
Anti-HTN
Macrolide
Antiemetics
Antipsychotics
TCAs
BPH medications
Work up
Cardiogenic: Echocardiogram, Holter monitoring, event monitor; consider implantable loop recorder, exercise stress testing
Non cardiogenic: Carotid sinus massage, Head tilt testing (differentiates neurally mediated vs orthostatic)
Treatment
Neurally mediated: avoid precipitating factors, counter-pressure (squat, cross legs). Meds with no clear benefit.
Orthostatic hypotension syncope: counter-pressure, education; consider midodrine or fludrocortisone.
Cardiogenic: treat etiology.
Other pearls:
Sudden onset, occurs in supine position, with palpitations/chest pain: likely cardiogenic.
Sx with position change or prolonged standing, precipitated by certain activities, preceded by autonomic prodrome (abdominal pain, nausea, vomiting): likely neurally mediated vs orthostatic.
Frequent and prolonged syncope: consider psychogenic.