0071643192.pdf

SYNCOPE

Syncope is defined as a transient loss of consciousness and postural tone with

subsequent spontaneous recovery. It results from transient cerebral hypoperfu-

sion from a variety of causes (see Table 2.25). It is most commonly benign but is

associated with life-threatening conditions. A post-ictal period is notably absent,

differentiating syncope from seizure.

SYMPTOMS/EXAM

■ Transient loss of consciousness

■ Complete recovery without intervention

■ Other symptoms and exam findings vary with underlying etiology.

■ Table 2.26 lists the classic presentations of syncope.

DIFFERENTIAL

■ It may be difficult to differentiate syncope from seizure.

■ A history of seizures makes a seizure more likely.

■ In rare instances, true syncope leads to seizure.

■ Both may be associated with extremity movement and urinary incon-

tinence.

■ A classic aura, post-ictal confusion, and muscle pain indicate seizure.

CARDIOVASCULAR EMERGENCIES

TABLE 2.25. Causes of Syncope

Acutely life-threatening vascular catastrophe

Aortic dissection, ruptured AAA, ruptured ectopic, subarachnoid hemorrhage, tamponade,

PE, severe hemorrhage (GI, retroperitoneal etc.)

Obstruction to cardiac flow

Aortic stenosis, hypertrophic cardiomyopathy, congenital heart disease, myxoma

Primary dysrhythmia

Vast majority occur with underlying structural heart disease (congenital or acquired) or

ischemia.

Exception to above is familial disorders (eg, congenital long QT syndrome, Brugada

syndrome).

Neurocardiogenic or reflex-mediated

Abnormal autonomic response to stimulus →vagal hyperactivity and symptoms.

Classic vasovagal, carotid sinus syndrome, cough, micturition

Medication-induced

Orthostatic

Neurologic

Transient ischemic attack, subclavian steal, migraine

Psychiatric (hyperventilation)

In patients who present with

syncope, the following factors

increase the risk of

dysrhythmia or sudden death:

1. Age > 45 years old


2. History of ventricular
   dysrhythmias


3. History of CHF


4. Abnormal ECG