SIM Flashcards
Epidemiology of syncope
- 3-37% lifetime prevalence
- 6% annual incidence in institutionalized elderly
- 3% of ER visits
- 1 % of hospital admissions
V tach
- three or more consecutive beats of WIDE QRS ventricular origin at 100-200 bpm
- stable = asymptomatic
- unstable = symtpoms
Distinguish between neurally (reflex) mediated, cardiac, orthostatic, other causes
l
Neurally (reflex) mediated syncope
- vasovagal (pain, fear, emotional distress, prolonged standing) 18% prevalence
- situational (urination, defecation, coughing, sneezing, swallowing, exercise, weight lifting, etc.) 5% prevalence
- carotid sinus syncope (shaving, massage, etc.) 1% prevalence
Cardiac syncope
- Arrhythmias (14% prevalence)
- SA/AV node dysfunction
- PSVT
- paroxysmal v tach
- ischemia/CAD
- medication effects
- pacer/ICD dysfunction
- inherited syndromes (long QT, etc.) - Structural Disease (4% prevalence)
- obstructive cardiac valve disease
- ACS
- obstructive cardiomyopathy
- atrial myxoma
- acute dissection of aorta
- pericardial disease
- pericardial tamponade
- pulmonary HTN
- PE
Orthostatic syncope
diarrhea, hemorrhage, vomiting, adrenocortical insufficiency
8% prevalence
Other causes of syncope
34% prevalence (of unknown cause of syncope)
Management of stable v tach
l
Management of unstable v tach
l
Labs for syncope
- telemetry (long qt, arrhythmia)
- pulse-oximetry
- 12 lead EKG
- CBC
- glucose
- urine HCG
- BNP
Definition of syncope
transient loss of consciousness 2* to cerebral hypoperfusion
characterized by:
- rapid onset
- short duration
- complete spontaneous recovery
Autonomic Dysfunction
- 1* autonomic failure (Lewy body disease, Parkinson disease)
- 2* autonomic failure (diabetic neuropathy, amyloid neuropathy, spinal cord injury)
- medications (antihypertensives, diuretics eg. HCTZ, TCAs, phenothiazines, etc.)
- alcohol
- exercise
- post-prandial
neurally mediated etiology clues
defecation urination prolonged coughing pain fear heat exposure
cardiogenic etiology clues
syncope during prone posture during exercise palpitations startling more likely prolonged QT syndrome
autonomic dysfunction etiology clues
standing quickly prolonged standing postprandial heat exposure following cessation of exercise
Syncope distribution by peak incidence
bimodal
- age 10-30
- age > 65
Symptoms of unstable vtach
chest pain
dyspnea
hypotension (SBP
Causes of vtach
CAD cardiomyopathy electrolytic abnormality myocardial ischemia hypoxemia acidosis idopathic
Tx of unstable vtach
- immediate synchronized cardioversion (50 joules initially, repeat at increased energy levels 100, 200, 360 as necessary)
Tx of stable vtach
- amiodarone
- plan for elective synchronized cardioversion
vtach long-term Tx
*DC cardioversion is safest and most effective
- implantable cardioverter-defibrillator (ICD)
- amiodarone
- beta blockers
AHA guidelines for driving after arrhythmia
6 months arrhythmia-free interval before driving
