Syncope Flashcards
Syncope is defined as
a sudden transiet loss of consciousness with inability to maintain postural tone
Syncope by whatever mechanism is caused by lack of adequate cerebral blood flow with loss of consciousness and inability to remain upright
Most common cause of syncope in the normal pediatric population
Neurocardiogenic syncope
aka vasovagal syncope
aka fainting
Vasovagal syncope is classical associated with
a prodrome that includes diaphoresis, warmth, pallor, or feeling lightheadedness
and is often triggered by a specific event or situation such as pain, medical procedures, or emotional distress
this type of syncope is characterized by hypotension and bradycardia
The most important goal in the evaluation of the new patient with syncope is
to diagnose life-threatening and cardiac causes of syncope so that these causes can be managed
The most important tool in evaluation is
Careful history
Features of Syncope in contrast to Seizures
Relation to posture
Pallor
Diaphoresis
With cardiovascular signs
Features of Seizures in contrast to Syncope
Injuries
Urinary incontinence
Tongue biting
Postictal confusion/headache
Features suggestive of cardiac syncope
No prodrome
Occurrence during exercise
Injury (indicates sudden occurence)
Syncope while recumbent
Family history of sudden death
A loud and single second heart sound is suggestive of
primary pulmonary hypertension
may also have an ejection click and the murmur of pulmonary insufficency
remarks on patients with first episode of syncope
must have an ECG obtained
looking primarily for
- QT interval prolongation
- preexcitation
- ventricular hypertrophy
- T-wave abnormalities
- conduction abnormalities
In patients for whom there is a strong suspicion of a paroxysmal arrhythmia, this may be the most effective means of diagnosis
implantable loop recorder
If a reentrant tachyardia (AVNRT, AVRT) is found, this may be indicated
catheter ablation
If bradycardia from AV block was the cause of the syncope, this may be warranted
pacemaker
These patients may require implantable cardioverter-defibrillator (ICD)
Medically refractory malignant arrhythmias
- HCM
- long QT syndrome (LQTS)
- arrhytmogenic cardiomyopathy
- catecholaminergic polymorpohic V tach (CVPT)
These patients should be referred for surgery
With structural heart disease (valvular disease or coronary artery anomalies)
3 types of orthostatic disorders
- Postural tachycardia syndrome (POTS)
- Orthostatic hypotension (OH)
- Reflex syncope
Remarks on POTS
With the phenomenon of initial orthostatic hypotension (IOH) where syncope is very short (30-60 secs), and BP returns to baseline in 30-60 seconds
Patient complains of lightheadedness and “blacking out” or tunnel vision 5-10 sec after standing
(POTS requires symptoms while upright)
Remarks on OH
OH is defined as sustained decrease in SBP of >20 mm Hg of DBP >10 mm Hg in the 1st 3 min of upright tilt
rarely occurs in children
patient frequently has no symptoms despite very low pressures
Remarks on reflex syncope
i.e., vasovagal or neurally mediated
defined as relatively sudden change in autonomic nervous system activity that leads to a sudden decrease in BP, HR, and cerebral perfusion
