Syncope Flashcards
Syncope
A transient loss of consciousness accompanied by a loss in postural tone, followed by a return to baseline function
- if no return to base line = SCD
- results from global hypo-perfusion to cerebral cortices
- is a symptom, must find out why it occurred
Most common age groups are 10-30 and >70 yr olds
Pathophysiology of syncope
Usually results once a fall in systolic BP to <50mmHg or lower
- will return back to baseline afterwards however
Neurally mediated syncope (reflex syncope)
- also called vasovagal syncope*
- most common cause of syncope and is benign
Mixed group of disorders w/ final pathway being hypotension, vasodilation and bradycardia
- increases parasympathetic tone And baroreceptors responses
- loss of sympathetic tone
Symptoms before passing out includes:
- prodromal symptoms
- dizzy/light head ness
- nausea/vomiting
- pallor
- ab pain
Patient regains consciousness quickly and is otherwise fine
- results in no increases in mortality
Carotid sinus hypersensitivity
Type of reflex-mediated syncope
Results from external pressure at the carotid sinus where the carotid is extra sensitive
Includes the following possible reasons:
- shaving
- tight collar
- turning of the head
- coughing
- dedication/micturition
- swelling
- stressful situation syncope
Symptoms are the same as vasovagal and may also include possible asystole
NOT life threatening
Orthostatic syncope
Syncope associated w/ drop in systolic BP (>20mmHg/>10mmHg) when changing position to standing up
- very common in elderly patients since the medications they are taking
Is an autonomic dysfunction and can also be induced by the following meds
- BBs
- CBBs
- nitros/ vasodilators
Possible physical reasons include:
- volume/blood loss
- major dehydration
May be life-threatening but depends
How to test for orthostatic hypertension
Have patient lie down quietly for five minutes
- check BP
Have patient stand up quickly and check blood pressure after 3 minutes
If the patients 2nd BP measure decreases 20/10mmHg or more, they have orthostatic hypotension
Serious causes for cardiac syncope
cardiac syncope is the most dangerous
1) Arrhythmias
- sinus node dysfunction (sick sinus, SA blocks)
- Stokes-Adams attack (syncope by heart block)
- A fib
- type 2 or 3rd degree heart blocks (leads to stokes-Adams
- tachyarrthmias
2) valvular diseases
- especially AS
- no prodromal symptoms will be present no warning signs
Tachyarrthmias w/ cardiac syncope
Heart rate >200 can cause syncope
- caused by decreased diastolic filling leading to poor perfusion to carotid, hypotension and ischemia
tachyarrthmias are the most concerning for cardiac syncope
Groups of patients that have increased chance of ventricular arrhythmias
Ischemic heart disease
- 3% of patients w/ MI will have a major syncopal episode(s)
Long QT syndrome
- mechanism PVCs that occur naturally
- defective sodium and potassium channels that leads to increase repolarization
- QTc >450msec is the norm (or greater than half the rate of RR interval)
- very predisposed to TdS
- is also very likely caused by hypokalemia or hypomagnesemia
Brugada syndrome
Cardiomyopathies
- especially HCM
Congestive Heart failure
- w/ <35% EF
WPW disease
Romano ward vs jervell syndromes
Both are long QT syndromes
Jervell = presents w/ congenital deafness
Romano-ward = presents w/out congenital deafness
WPW w/ atrial fibrilation/flutter
Dangerous since the ventricular rates will get above 300bpm
- will induce V. Fib or asystole if not treated
Hypertrophic cardiomyopathy
Most common cause of sudden death of <35 year old males
Very genetic based w/ 60-70% of people having an affected family member
- autosomal dominant but effects men slightly more than women
Most common symptoms
- passed out w/ exercise or strenuous movements
- also proved to denaturation syncope
- EKG shows LVH
- always shows some level of angina w/ exercise
- septal hypertrophy will be common
- murmur is louder along left sternal border
Tx:
- surgical myomectomy
- ICD
- septal ablation
Aortic stenosis w/ syncope
10% of patients w/ severe aortic stenosis will show syncope
- cardiac output will not increase w/ exercise as well (similar to HCM)
Presents w/ increased risk of atrial fibrillation due to stretched irritated SA node cells (left atrial enlargement will occur)
- not much of a risk for ventricular arrhythmias but can be induced by a fib
- # 1 cause is congenital bicuspid aortic valve*
HF w/ syncope
Almost always occurs if the HF is presented w/ ejection fractions of <35%.
- increased risk of v fib
- requires ICD placement
Other less common causes of cardiac syncope
Right atrial myxoma (obstruction of right atria)
PEs
Metabolic problems (specifically hypoglycemia)
Vascular emergencies
