Definition
• LOC/postural tone from abrupt drop in cerebral perfusion w/ spontaneous recovery. Presyncope, near-syncope: As above, but sxs resolve before LOC.
• Accounts for 1–1.5% ED visits & up to 6% hospital admission
History
• Ask about activity/posture preceding event, precipitants, prodromal sxs (weakness, lightheadedness, diaphoresis, constriction of visual fields, blurred vision), length of syncopal episode (<5 s suggests cardiac; >5 s suggests vasovagal)
• ROS, PMH (cardiac dz), meds, & FHx (sudden cardiac D) are very important
• Different from szs: Typically abrupt onset, short duration, quick recovery (seconds–minutes), no tongue biting/incontinence. Syncope can cause brief myoclonic jerking (usually 6–8 s).
• Use hx or physical exam findings consistent w/ heart failure to help identify pts at higher risk of adverse outcome
• Consider older age, structural heart dz or a h/o CAD as RFs of adverse outcomes
• Consider younger pts w/ syncope that is nonexertional, w/o signs of cardiac dz, FHx of sudden cardiac death, & w/o comorbidities to be at low risk of adverse events
Evaluation
• Obtain a standard 12-lead ECG in pts w/ syncope
• ECG should be observed for stigmata of diseases that increase risk of malignant dysrhythmia (HOCM, ARVD, Brugada syndrome, prolonged QTc, pre-excitation syndrome, coronary artery abnormalities)
• Lab testing & advanced testing such as echo or head CT need not be routinely performed unless guided by sp findings in hx or physical exam
• Consider CBC, lytes, continuous cardiac monitoring in most pts; add hCG (for women)
• Consider cardiac markers, UA, stool guaiac, head CT in elderly
Disposition (Ann Emerg Med 1997;29:4)
• Home if low-risk cardiac features: (1) Age <45, (2) nl ECG, (3) nl exam. Consider outpt f/u.
• Admit if high-risk cardiac features: (1) Age (unknown age threshold, but continuous variable), (2) h/o cardiac dz (esp e/o heart failure or structural heart dz), (3) one or more Criteria of San Francisco Syncope rule
• Other if diagnosed or suspected life-threatening diseases (eg, MI, aortic dissection, GI bleed), acute neurologic abnlty (eg, stroke, sz), ± for congenital heart dz, FHx sudden death, exertional syncope in pt w/o obvious cause
Pearl
• Any pt w/ ICD who has syncope should have their ICD interrogated by an appropriate specialist given the high likelihood of malignant dysrhythmia in such pts, which was likely the initial indication for ICD placement prophylactically.
Decision Rules in Evaluation of Syncope
Guideline: Huff JS, Decker WW, Quinn JV. Clinical policy: Critical issues in the evaluation and management of adult patients presenting to the emergency department with syncope. Ann Emerg Med. 2007;49(4):431–444.
CARDIAC SYNCOPE
IHSS/HOCM
History
• Precipitated by exertion, lack of prodrome, lasts <5 s. PMH of cardiac dz, FHx of syncope or SCD.
Findings
• E/o heart failure (elevated JVP, S3), murmurs, LVH (S4, LV heave)
Evaluation
• ECG (LVH most common; see above), CXR (cardiomegaly), echo (essential test, shows LVH, LV outflow tract narrowing), ± cardiac cath
Treatment
• BB or CCB, amiodarone, surgery, &/or PM if severe
Disposition
• Admission, cardiology consult, as syncope is independent predictor of SCH
Pearl
• Echo to differentiate from valvular abnormalities, PHT; avoid nitrates for pts w/ CP, they decrease outflow tract size; increased risk for SCH, SBE
Pulmonary HTN
History
• Precipitated by exertion; PMH: IPAH, connective tissue d/o, L-sided HF, MS/MR, COPD
Findings
• E/o right-sided HF (elevated JVP, peripheral edema, RUQ fullness, abd distention, RV heave, PR/TR)
Evaluation
• ECG (RAE, RBBB, RVH), CXR (enlarged pulmonary vasculature, RA, RV), cardiology consult, echo (increased RSVP, PR/TR), BNP, ± cardiac cath
Treatment
• O2, diuretics if presence of failure; consult cardiology for further tx: Digoxin, CCB, dobutamine & inhaled NO for decompensated PHT, prostacyclins, PDE-5 inhibitors
Pearl
• Consider PE, LV dysfxn, parenchymal lung dz on differential
Subclavian Steal
History
• A/w arm exercise, causing retrograde flow of blood in ipsilateral Vertebral artery; PMH atherosclerosis; can cause vertigo, dizziness, pain w/ use of ipsilateral arm
Findings
• SBP differential in the 2 arms (45 mmHg), asymmetric pulses
Evaluation
• Check BP in both arms, CXR (r/o 1st rib), duplex US carotid, SC, vertebral arteries, CTA aortic arch, vascular surgery consult
Treatment
• Potential surgery
Disposition
• Admission
Vertebrobasilar Insufficiency
History
• Consider in anyone of advanced age w/ new-onset vertigo & no known cause; lasts seconds–minutes; assoc sx: HA common, also dysarthria, ataxia, weakness, numbness, double vision
Findings
• Dysarthria, abnl gait, +Romberg, visual field deficit, nystagmus
Evaluation
• CT head (r/o bleed), MRI/MRA, neurology consult
Treatment
• Meclizine for sx relief, ?anticoagulation
Disposition
• Admission
Pearl
• Always test gait when pts have vertigo
NEUROCARDIOGENIC SYNCOPE
Vasovagal/Carotid Sinus Hypersensitivity (CSH)
History
• Precipitated by stressors: Sight of blood, emotional distress, fatigue, prolonged standing, warm environment, nausea, vomiting, cough, micturition, defecation, swallowing
• CSH a/w head turning, shaving. +prodrome. Lasts >5 s.
Findings
• Typically nl exam
Evaluation
• ECG
Disposition
• D/c if low risk, admit if high risk (see above)
Pearl
• No increased risk of D, MI, stroke (Ann Emerg Med 1997;29:459; NEJM 2002;347:878)
ORTHOSTATIC HYPOTENSION
Hypovolemia
History
• Precipitated by position change, +prodrome, typically >5 s.
Findings
• Orthostatic hypotension (+ → supine to standing causes >20 mmHg drop SBP, >10 mmHg drop DBP, or >10–20 bpm increase HR), hypotension (if severe or 2/2 to blood loss)
Evaluation
• Stool guaiac for occult blood
Treatment
• Fluids (PO if pt able to tolerate, o/w IV)
Disposition
• D/c if low risk & sxs resolve w/ hypotension; admit if high risk, persistent hypotension despite rehydration, or unexplained hypovolemia
Pearl
• Assess cause of hypotension (decreased PO intake vs. occult bleed)
Medications
History
• Use of vasodilators (α-blockers, nitrates, ACEI/ARB, CCB, hydralazine, phenothiazines, antidepressants), diuretics, negative chronotropes (BB, CCB), antiarrhythmics (class IA, IC, III), psychoactive meds (antipsychotics, TCAs, barbiturates, benzos, EtOH)
Treatment
• Discontinue offending agent, if sxs severe w/ hypotension, give fluids, ± tx overdose w/ glucagon (βB), IV calcium (CCB), or sodium bicarb (TCAs)
Disposition
• May require admission for changes to med regimen
Autonomic Dysfunction
History
• Precipitated by position change, PMH of DM, prior episodes
Findings
• Orthostatic hypotension (+ → supine to standing causes >20 mmHg drop SBP, >10 mmHg drop DBP, or >10–20 bpm increase HR)
Treatment
• Avoid sudden changes in position, treat underlying d/o
Pearl
• This is a Dx of exclusion, esp in elderly. R/o cardiac & neuro causes 1st.