Syncope

work and brain imaging are necessary unless the underlying cause of the status epilepticus is clear.

SYNCOPE

Syncope involves the sudden but brief loss of consciousness and loss of muscle tone. Most patients spontaneously recover once they are recumbent but, until then you will see a weakness of the pulse, cool extremities, and shallow breaths with involuntary muscle jerking. This can be preceded by near-syncope, which is the sensation of an impending fainting episode. Seizures by themselves are not syncopal episodes.

While most syncope comes out of inadequate blood flow to the brain, a few cases come from low substrate levels in the brain, such as insufficient oxygen or low glucose levels. Look first for situations of low cardiac output. These can come from systolic dysfunction, diastolic dysfunction, obstruction to cardiac outflow, poor venous return to the heart, or arrhythmias. These are collectively referred to as vasovagal syncope. Orthostatic hypotension comes when the normal mechanisms to increase blood to the brain, such as vasoconstriction or sinus tachycardia, do not happen when standing up.

Evaluate syncope as soon as possible after the event. Find out the inciting events and if there were prodromal symptoms suggesting presyncope. Find out the duration of the syncopal episode. In a review of symptoms, look for evidence of occult bleeding, palpitations, chest pain, vomiting or diarrhea, and risk factors for pulmonary embolism. Determine if there have been prior similar events, known heart disease, or use of vasodilators, diuretics, or antiarrhythmic drugs.

Your examination must include orthostatic blood pressure measurements. Listen for heart murmurs and note the patient’s mental status. Obtain an ECG. Check the stool for occult blood and get a neurological examination. Pulse oximetry, tilt table testing, or echocardiogram might be necessary. Rarely will CNS imaging be necessary.

Things you should be most concerned about include multiple recurring instances of syncope, syncope during exertion, older age, new heart murmur, secondary injury from the episode, and a family history of sudden death.