Syncope Flashcards
Which group of syncope are at the greatest risk of mortality and morbidity
patient with cardiovascular history and any cause of syncope are at the greatest risk for mortality and morbidity
Discuss the pathophysiology of syncope
The final common pathway of all syncope is dysfunction of both cerebral hemispheres or brainstem (reticular activating system) , usually from acute hypoperfusion.
Reduced blood flow can be regional (vasoconstriction) or systemic (hypotension)
Syncope and presycnope should be considered on a continuum with similar causes for both
generally reduced cerebral blood flow of more then 35% will lead to loss of consciousness
By definition syncope is transient
Discuss broad categories for cause of syncope
1) neurally (reflex) mediated
2) orthostatic hypotension mediated
3) cardiovascular mediated
Other causes of transient loss of consciousness that do not fall into these categories are likely mediated by other pathways these include – seizure, hypoglycaemia, certain toxins, metabolic derangements, hyperventilation, primary neurological condition and psych disorderd n
Discuss DDX of cardiovascular mediated syncope
Can be divided into outflow obstruction, reduced cardiac output and other
Outflow obstruction
- mitral, aortic or pulmonary stenosis
- HOCM
- Atrial myxoma
- PE
- Pulmonary hypertension
- Cardiac tamponande
- congenital heart disease
Reduced cardiac output (arrhythmia)
- Tachycardias
- -SVT
- -VT
- -VF
- -WPW
- -Torsades
- Bradycardias
- -Sinus nodal disease
- -prolonged QT syndrome
- -Brugad’s syndrome
- -Pacemaker Malfunction
Other
- -Aortic dissection
- -MI
- -Cardiomyopathy (HOCM, ARVD)
Discuss neurally mediated causes of sycnope
Reflex
- emotion
- pain
- instrumentation
- valsalva
Situational
- carotid sinus sensitivity( necktie, shaving) ]
- post exercise
- GIT – swallowing, vomiting, defecation
- postmicturation
Discuss orthostatic mediated causes of syncope
Volume depletion – anemia hemorrhage, dehydration
Primary autonomic failure
Drug induced
List critical diagnosis to consider in syncope
MI Life threatening dysrhythmias thoracic aortic dissection crtical aortic stenosis HOCM Pericardial tamponande AAA massive PE Subarachnoid haemorrhage Stroke Toxic metabolic derangements Severe hypovolaemia or hemorrhage Ruptured ectopic pregnancy Sepsis
Discuss which patient need to be admitted
Hospitalization is required for patients with chest pain, unexplained SOB, history of CCF or significant valvular disease
Patients with ECG evidence of ventricular dysrhythmias, ischemia, significantly prolonged QT or new bundle branch block should also be admitted
Monitoring should be considered for anyone older then 65, pre-existing cardiovascular or congiental heart disease, family history of sudden cardiac death, serious co-morbididites such as DM or exertional syncope
Safe to send home women under 55 and men under 45 for outpatient follow-up without period of monitoring if likley neurally mediated
Key characteristic to be ascertained are rate of onset, position on onset, duration and rate of recovery
List markers of increased short term risk in syncope patient
- Older then 65
- male
- history of CCF
- history of CVS or serious dysrhythmia
- history of structural heart disease
- family history of early sudden death
- syncope without prodrome
- exertional syncope
- syncope during supine position
- dyspnoa
- hypotension
- abnormal ECG
- anaemia with haematocrit <30% or HB <90g/l
Discuss approach to syncope patient
Main goal is to separate those with concerning features from those with a benign course
- Setting of sycope can be a key (post micturation, veno puncture)
- position of patient - sitting to standing
- prodrome
- prior episodes
Discuss DDX of patient with focal hypoperfusion of CNS structures
CVA Hyperventilation Subclavian steal Subarachnoid haemorrhage Basilar artery migraine Cerbral syncope
Discuss DDX of syncope patient with nroma cerbral pergusion
Hypoglycaemia
Hypoxemia
Seizure
Narcolepsy
Psychogenic (anxiety, conversion panic attack)
TOxic ( Drugs, CO, Other, Undetermined ca)
Discuss sanfransicsco syncope rule
A risk factor tool looking at 5 criteria to identify those who are high risk patient with syncope
Include
1) heart failure history
2) ECG changes (EKG changed, or any non-sinus rhythm on EKG or monitoring)
3) SOB
4) haematocrit <30%
5) systolic <90 at triage
This rule has a 96% sensitivity and 62% specificity for serious outcome - negative predictive value: 99.2%; positive predictive value 24.8%
List cause of cardiac syncope in children (Look at ECG in children)
- brugada
- long qt
- short qt
- WPW
- ARVD
- HOCM
Describe canadian syncope score
30 day risk for serious adverse event
1) predisposition to vasovagal symptoms -1
2) heart disease history (CAD, AF, CHF or valvular disease) +1
3) SBP <90 or >180 +2
4) elevated TNI +2
5) abnormal QRS axis +1
6) QRS duration +1
7) QTC >480+1
8) ED diagnosis
- vasovagal -2
- cardiac syncope +2
- neither 0
