These might involve the avoidance of the standing posture and tapering off exertion rather than suddenly stopping. POTS and syncope often coexist. There are a couple of exceptions that we are aware of. One is the syncope at rest that follows exertion in some subjects. Uncommonly, the subject who has had one or more syncopal episode induced by standing will have an additional one even after sitting or lying down.
Neurocardiogenic syncope is generally benign and death is extremely rare.
Sudden death is generally due to an Arrhythmia. One reason why the patient with frequent syncope needs a cardiologic opinion is that it is important to ensure that the patient truly has neurocardiogenic syncope and not a cardiac rhythm abnormality. After a number of seconds, the heart restarts spontaneously. We have not had any confirmed cases of NCS as a cause of sudden death at Mayo. In November of this year a special supplement to the American Journal of Medical Sciences will be published on OI and Orthostatic Tachycardia.