A7- Syncope Flashcards
WHat is syncope?
the suddent transient loss of consciousness and postural tone with spontaneous recovery.
Loss of consciousness occurs within 10 secinfd of hypoperfusion of the reticular activating system in the mid brain.
What is presyncope? Symptoms?
What is another name for presyncope?
Pre-syncope is the feeling that you are about to faint. Someone with pre-syncope may be lightheaded (dizzy) or nauseated, have a visual “gray out” or trouble hearing, have palpitations, or feel weak or suddenly sweaty. When discussing syncope with your doctor, you should note episodes of pre-syncope as well.
Symptoms include: dizziness, lightheadedness or faintness, weakness, fatigue, and visual and auditory disturbances
Syncopal prodrome
______ causes of syncope have the highest mortality rates
Cardiac causes of syncope have the highest mortality rates
How can syncope impact someones life
Cause anxiety/Depression
Alter Faily Activities
Restricted Driving
Change Employment
Explain the maintenance postural Normal tension
When standing there is a pooling of 500-1000mL of blood in the lower extremities and slanchi circulation.
There is a decrease in venous return to the heart and reduced ventricular filling that result in diminished cardiac output and blood
These haemodynamic changes provoke a compensatory reflex response, initiated by the baroreceptors in the carotid sinus and aortic arch, resulting in increased sympathetic outflow and decreased vagal nerve activity
The reflex increases peripheral resistance, venous return to the heart, and cardiac output and thus limits the fall in blood pressure
Syncope causes can be split into 5 groups.
What are they?
Neurally-Mediated
Orthostatic
Cardiac Arrhythmia
Structural Cardio-Pulmonary
Non Cardio-Vascular
Example of Neurally mediated syncope causes?
Vasovaal
Carotid Sinus
Situational
- Cough
- Post-Micturition
Example of Orthostatic syncope causes?
Drug induced
ANS Failure: Primary or Secondary
Brady: Sick Sinus, AV Block
Tachy: VT, SVT
Long QT Syndrome
Example of Structural Cardio-Pulmonary syncope causes?
Aortic Stenosis
HOCM
Pulmonary Hypertension
Example of Non-Cardio Vascular syncope causes?
Psychogrnic
Metabolic eg hyper-ventilation
Neurological
What are some causes of syncope in a younger patients?
Vasovagal
Situational
Psychiatric
Long OQ
Brugada Syndrome
WPW syndrom
RV
Dysplasia
Hypertophic Cardiomyopathy
Catecholamnergic VT
Other genetic syndromes
What are some causes of syncope in a older patients?
Cardiac: Mechanical, Arrhythmic
Orthostatic hypotension
Drug induced
Neurally mediated
Mutifactorial
What is Cardiac Syncope?
Severe obstruction to cardiac output or rhythmn disturbace can lead to syncope
a) due to strucural abnormalites leading to flow: exertional syncope is a common mindeststion of all types of heart diseae in which cardiac output is fixed an ddoes not rise or may fall with exercise
b) LVOTO: common conditiona AS,HCM
Syncope occurs in what percentage of people with aortic stenosis?
<42%
What is the mechanism of syncope for people with aortic stenosis?
Due to fixed CO, CO Decreases on exertion due to reflex fall in perioheral vascular resistance
30 % Hypertophic cardiomyopathy patients have syncope
Explain its mechanism
Dynamic LVOTO is worsened by an increase in LV contractility (stinulatin the LV mechanoreceptors), decrease in chamber size, or decrease in after-load.. (Hence, a Valsalva maneuver, severe cough or drugs precipitates hypotension and syncope.
How does RVOTO cause syncope?
inability to incrase CO in association with a reflec fall of peripheral resistance results in hypotension and syncope
How does CAD cause syncope?
sudden pump failure producing hypotension and decreased perfusion of the brain
What is the common arrhythmia that causes syncope?
Ventricular tachycardia?