11. Syncope Flashcards
Syncope distribution
Initial 20-30 and older
Syncope ddefn
transient LOC and postural tone with rapid, complet spont recovery (cause by global hypopefusion)
3 broad categories of syncope
reflex
orthostatic
cardiac
How does reflex syncope occur?
inappropriate vasodilation, bradycardia or both - includes vasovagal, carotid sinus syndrome and situational
Vasovagal syncope - how does this occur?
prodrome nausea, pallor, sweat, lightheaded, change in vision
Carotid sinus syndrome
pause of >/=3s and or >/=50mm hbg decrease in bp when stimulate carotid sinus
Orthostatic hypotension defn
decr bp sbp 20, dbp 10 within 3 min of standing (HR incr 30)
Cardiac diagnosis associated with syncope - 2 dysrh
tachydys
bradydys
Cardiac diagnosis associated with syncope - structural causes
hcm
ao stenosis
severe pulmonic stenosis
ac MI
cardiac masses like myoma
pericrdial tamponade
prosth valve dysfunc
vad dysfunc
Cardiac diagnosis associated with syncope - 3 cardiopulmonary causes
ac ao dissection
pe
phtn
Name 5 bradyarrh associated with syncope
ABblock mobitz 2 and III
sinus pause >3s
sick sinus syndrome
persistent sinus brady <40s
Name 5 tachydysrh assoc with syncope
vent tachy: Monomorphic, polymorphic, vent fib
SVT: afib/flutter, AVNRT, AVRT
Alt L and RBBB
PM or ICD malfunc
ECG abnormalities potentially associated with syncope
signs of AMI
Pre-excitation of wpw
long qtc
short qt
RBBB with brugada
inverted t wave in R precordial leads and epsilon waves sugg of arrhthmogenic RV cardiomyopathy
LVH, abn q wabes or deep inverted HCM
RV strain pattern suggestive of PE
Syncope mimics
mechanical fall
intxoication
hypoglycemia
hypoxemia
head truama - concussion
seizures
tia
cataplexy
drop attack
psychogenic syncope
What medications are assoc with orthostatic hypotension:
- Vasodilators:
Beta blockers, calcium channel blockers, nitrates, hydralazine, angiotensin-
converting enzyme inhibitors, angiotensin receptor blockers, phenothi-
azines, phosphodiesterase inhibitors (e.g., sildenafil, tadalafil)
Diuretics (e.g., hydrochlorothiazide, furosemide)
Central antihypertensives (e.g., clonidine, methyldopa)
QT-prolonging agents (e.g., amiodarone, flecainide, procainamide, quini-
dine, sotalol) - Psychoactive agents:
Anticonvulsants (e.g., carbamazepine, phenytoin)
Antipsychotic drugs (e.g., olanzapine, risperidone)
Antiparkinsonian agents (e.g., levodopa, pramipexole)
Central nervous system depressants (e.g., barbiturates, benzodiazepines) Antidepressants (e.g., monoamine oxidase inhibitors, Selective serotonin
receptor reuptake inhibitors, trazodone, tricyclic antidepressants) Opiates analgesics (e.g., morphine)
Sedating antihistamines (e.g., diphenhydramine)
Cholinesterase inhibitors (e.g., donepezil, tacrine, galantamine) Alcohol
Digitalis
Neuropathic agents (e.g., vincristine) Bromocriptine
Routine laboratory testing, although often done for patients with syn- cope,…? recommended?
is not supported by evidence and is not recommended in national guidelines.
Critical diagnoses assoc with syncope: list 8
Myocardial infarction
Life-threatening dysrhythmias
Acute aortic dissection
Critical aortic stenosis
Hypertrophic cardiomyopathy Pericardial tamponade
Abdominal aortic aneurysm (ruptured)
Massive pulmonary embolism Subarachnoid hemorrhage Toxic-metabolic derangements Severe hypovolemia or hemorrhage
Ruptured ectopic pregnancy
Sepsis
Systemic Hypoperfusion Resulting in Central Nervous System Dysfunction
Cardiovascular System–Mediated:
Outflow Obstruction
Mitral, aortic, or pulmonic stenosis Hypertrophic cardiomyopathy Atrial myxoma
Pulmonary embolism
Pulmonary hypertension Cardiac tamponade Congenital heart disease
Systemic Hypoperfusion Resulting in Central Nervous System Dysfunction
Cardiovascular System–Mediated:
Reduced CO - tachy
Supraventricular tachycardia Ventricular tachycardia Ventricular fibrillation Wolff-Parkinson-White syndrome Torsades de pointes
Systemic Hypoperfusion Resulting in Central Nervous System Dysfunction
Cardiovascular System–Mediated:
Reduced CO - brady
Sinus node disease
Second-degree and third-degree atrioventricular block Prolonged QT syndrome
Brugada syndrome
Pacemaker malfunction
Implanted cardioverter-defibrillator malfunction
Systemic Hypoperfusion Resulting in Central Nervous System Dysfunction
Cardiovascular System–Mediated:
Reduced CO - other CVD x3
Aortic dissection
Myocardial infarction Cardiomyopathy
DDX vasovagal neurally medial
Reflex syncope (vasovagal): Emotion
Pain Instrumentation
Valsalva—elevated intrathoracic pressure, weightlifting; tussive, sneeze Situational
Carotid sinus sensitivity (necktie, shaving syncope) Post-exercise
Gastrointestinal—swallowing, vomiting, defecation Post-micturition
Focal hypoperfusion of nervous system causing syncope ddx
Cerebrovascular disease Hyperventilation Subclavian steal Subarachnoid hemorrhage Basilar artery migraine Cerebral syncope
Central Nervous System Dysfunction With Normal Cerebral Perfusion Hypoglycemia
Hypoxemia—asphyxiation
Seizure
Narcolepsy Psychogenic
Anxiety disorder Conversion disorder Somatization disorder Panic disorder Breath-holding spells
Intoxication Medications
Carbon monoxide Undetermined causes
Recommended tests for syncope
glucose
ecg
hx and pe
labs per hx and pe
Canadian syncope risk score
- Predisposition to vasovagal syncope −1
- History of heart disease +1
- Any systolic pressure reading in the emergency department <90 or >180
mm Hg +2 - Troponin level >99th percentile for normal population +2
- Abnormal QRS axis (<−30 degrees or >110 degrees) +1
- Prolonged QRS interval >130 ms +1
- Prolonged corrected QT interval >.480 ms +2
- Emergency department diagnosis of vasovagal syncope −2
- Emergency department diagnosis of cardiac syncope +2
Score of −2 is very low risk, −1 or 0 is low risk, 1–3 is medium risk, and >3 is high risk
FAINT score syncope
- History of heart failure +1
- History of cardiac arrhythmia +1
- Initial abnormal 12-lead ECG result +1
- Elevated N-terminal pro b-type natriuretic peptide (NT proBNP) >125 pg/mL
+2 - Elevated high-sensitivity troponin T >19 ng/L +1
San Francisco Syncope Risk Score
- History of congestive heart failure
- Hematocrit <30%
- Abnormal findings on 12-lead ECG or cardiac monitoring 4. History of shortness of breath
- Systolic blood pressure <90 mm Hg at triage
Short term RF for syncope
- Older age
- Male gender
- Family history of early sudden death (under 50 years old) 4. Syncope without prodrome
- Exertional syncope
- Syncope while in supine position
- Palpitations before syncope
