syncope2 Flashcards
what is syncope?
The abrupt and transient loss of consciousness associated with absence of postural tone, followed by complete and usually rapid spontaneous recovery
A symptom and NOT a diagnosis
impact
30% of adult population will experience syncopal episode
3% of all ED visits in US
Can lead to significant morbidity
50% of the time a specific cause is NOT identified during initial evaluation
Important to distinguish Syncope from other causes of LOC:
Pre-Syncope: lightheadedness without LOC
Drop Attack: loss of posture without LOC
Seizure: Tonic-Clonic Movements that start WITH LOC (vs hypoxic myoclonus which can occur with syncope), post-ictal recovery period
hypoglycemia
hypoxia
types of syncope
Vasodepressor
AKA (Vasovagal/Neurocardiogenic)
Most Common
Cardiovascular (most dangerous)
Orthostatic Hypotension
Neuro / Functional / Psychiatric -
Vasodepressor
AKA (Vasovagal/Neurocardiogenic)
Most Common
decrease preload–>not enough blood to brain for short amount of time, comes back
Pain/Noxious Stimuli Situational (micturation (oldies), cough, defecation) Carotid Sinus Hypersensitivity (CSH) Fear (inc. vagal tone) Prolonged heat exposure
Arrhythmia – Tachycardia/Bradycardia
Mechanical – Aortic Stenosis, HOCM
Orthostatic Hypotension
Drugs: BP meds - Vasodilators, Diuretics, Alpha blockers
Autonomic Insufficiency (Parkinsons, DM, Adrenal Insufficiency)
Hypovolemia: Dehydration, Blood loss, infection
Neuro / Functional / Psychiatric -
Pseudosyncope
TIA or Vertebrobasilar Insufficiency
most important thing in syncope..
hx is absolute key!!
more vasodepressor syncope:
Due to excessive vagal tone
Vasovagal Hypotension: Initiated but stressful, painful situation
Situational Vasovagal Syncope: Associated with activity that may cause increase in vagal tone
- Micturation Syncope
- After Defecation
- Post Prandial
more vasodepressor syncope: Carotid Sinus Hypersensitivity: (Common in Elderly)
- Sensitive Baroreceptors in Carotid body – when activated can decrease HR and drop BP = possible Syncope
- May occur with pressure on neck – tight collar, turning neck
-if massage carotid body, it “goes haywire” causing dec. HR and BP
10 second pause of sudden cardiac death!
orthostatic syncope
one of the most common presentations in hospital
Common in Elderly
Essentially Pooling of blood in LE – while standing or sitting up – leading to decreased Preload = Syncope
causes of orthostatic syncope
Autonomic Insufficiency : ex: DM Neuropathy (not able to “squeeze down as fast”)
Hypovolemia:
- Dehydration (Decreased thirst/ infections) - Blood loss
Medications:
- Vasodilators (i.e. hydralizine) - Alpha Blockers (flomax, tamsulosin) - Diuretics
Orthostatic BP Measurement:
Measure same arm
Measure while patient laying, sitting and standing
Wait 5min between change of position
POSITIVE IF:
a drop in BP of >= 20 mmHg
or in diastolic BP of >=10 mmHg
or experiencing lightheadedness or dizziness
Cardiogenic Syncope
Mechanical or Arrhythmic
not able to maintain CO
Cardiogenic Syncope: mechanical problem
Valvular: (“less lanes of traffic”)
Aortic Stenosis
Pulmonic Stenosis (less common)
Structural:
HOCM
Severe Cardiomyopathy (i.e. DCM, EF 15!)
Myxoma (intracardiac tumor on septal wall obstructing mitral valve)
Cardiogenic Syncope: arrhythmias
Tachycardia:
SVT
VT
VF
Bradycardia:
Sinus Brady
AV blocks
AV dissociation
Aortic stenosis (mechanical cardiogenic syncope)
LV outflow tract gradient secondary to stenosis of Aortic Valve
Aortic Stenosis likely secondary to senile degeneration/ bicuspid aortic valve
CO= SV x HR
normal pressure gradient:
LV: 120/10, Aorta: 120/80, LA: 10
aortic stenosis pressure gradients:
LV: 200/25, Aorta 110/75, LA: 25
2 year mortality: 50%
*Syncope as presenting symptom Aortic Stenosis indicates Poor Prognosis: fix with sx: replace valve
FA: Aortic stenosis
Crescendo-decrescendo S1S2 systolic ejection murmur.
LV»_space; aortic pressure during systole. Loudest at heart base; radiates to carotids. “Pulsus parvus et tardus”—pulses are weak with a delayed peak. Can lead to
*Syncope, Angina, and Dyspnea on exertion (SAD).
Often due to age-related calcification or early-onset calcification of bicuspid aortic valve
Hypertrophic Obstructive Cardiomyopathy
??
severe sinus bradycardia EKG:
around 20!
high grade 2nd degree AVB EKG:
dropping every other QRS complex
regular P waves
“high grade”: could be mobitz 1 or 2
Third degree AVB EKG:
A-V dissociation (“marching at own beats”)
needs pacer
SA/AV nodal dysfunction with Pauses EKG:
almost 9 second pauses!!
needs pacer
arrythmias: bradycardia: consider different part of equation
CO=HRxSV
here the HR is low causing the decrease CO
