Syncope Flashcards
Components of syncope:
- rapid onset
- complete loss of consciousness AND postural tone
- Brief (30 sec to < 5min)
- Spontaneous recovery
Factors that could affect CO?
- structure (altered LVEF, or issues with outflow like HOCM/AS)
- LV volume (hemorrhage, renal/adrenal dysfunction, dehydration)
- Heart rate (brady vs. tachy; in tachy, too little time for ventricles to fill and you have decreased output because of low LVEDV)
Syncope originates with
low BP/global cerebral hypoperfusion, leading to low CO or low peripheral resistance
- cardiac syncope (arrhythmia, problems with venous return maybe, cardio-inhibitory)
- reflex syncope (vasodepression, inappropriate reflex)
- syncope secondary to orthostatic hypotention (more dealing with autonomic nervous failure or drug induced ANF)
Usually, cause of syncope is
unknown; however, could be vasovagal/carotid sinus, then cardiac, then orthostatic
Reflex or neurally mediated syncope:
- vasovagal: stress, pain, phobia
- situational: cough, sneeze, eat/pee/poop
- Carotid sinus hypersens;
think loss of symp tone leading to vasodilation/hypotension and bradycardia (could also lose blood volume)
Orthostatic hypotension defined as
drop in BP by 20/10 within 3 min of standing; have inadequate peripheral vasoconstriction;
think DAAD (drugs, autonomic dysfunction, alcohol, dehydration);
DRUGS: diuretics, EtOH, sedatives, alpha blockers
AUTONOMIC: Parkinson’s, MSA, Lewy body dementia
ALCOHOL
VOLUME DEPLETION: diarrhea/dehydration, hemorrhage
Cardiac syncope:
Bradycardia: drugs, electrolytes, conduction disease;
maybe tachyarrhythmia (VT or SVT);
HOCM (systolic murmur), aortic stenosis (systolic murmur), severe CHF (S3S4; lung with crackles)
What will help in diagnosing syncope?
HISTORY!! (are you hurt, any witnesses; also sudden noise syncope could be long QT syndrome)
Prodrome of vasovagal syncope is
nausea/abdo pain, dizziness, tinnitus, neck/shoulder pain, wobbling
Questions to witnesses:
- slumped or fell abruptly
- skin color (cyanotic, pale, flushed)
- any motor movements
- pattern of breathing
- duration of episode
- mental status post-event altered
- incontinence
Post-drome for vasovagal could mean
taking longer to recover (rapid recovery with arrhythmia and maybe post-ictal confusion/neuro deficits with seizure)
PE for syncope
- vitals, including supine/standing BP/HR
- pallor (anemia?)
- neck: carotid pulse!! bruits, JVP
- cardiac exam: regularity, rate, murmurs (structural disease)
- lungs: air entry, wheezing, crackles (heart failure)
- Neuro exam: any deficits?
Labs:
CBC (Hct); BMP (Na/K, BUN/creatinine)
High risk features of syncope:
- exercise-induced
- family history of SCD
- drop attack
- abnormal EKG
- pallor/anemia/electrolyte abnormality
FED AP the ball!!!
For testing of cardiac and neurogenic syncope:
Cardiac: echo, rhythm monitoring (Holter, MCOT, reveal), electrophysio study;
neurogenic: tilt-table testing (vasovagal syncope);
