[Dizziness and syncope : clinical case examples].

Syncope is defined as a transient, self-limiting loss of consciousness and postural tone due to transient global cerebral hypoperfusion. After syncope the following questions have to be answered: was it a syncopal episode, has the etiological diagnosis been determined, are there data suggestive of a high risk of cardiovascular events or death and what are the therapeutic options? Therefore, a standardized diagnostic work-up is necessary. This diagnostic work-up with differential diagnostic considerations is given for three clinical cases: a 52-year-old man experienced syncope while driving a car and on the morning of the same day syncope had previously occurred while in a standing position. The initial cardiological and neurological evaluation revealed no pathological findings but after implantation of a loop recorder a further syncope with a sinus arrest of 17 s occurred 1 year later. The patient received a single chamber pacemaker. The second case is a 79-year-old female with Parkinson's disease for many years and a primary autonomic dysfunction leading to dizziness and syncope due to pronounced blood pressure fluctuations with hypertensive and hypotensive phases. The last patient is a 22-year-old female with postural orthostatic tachycardia syndrome and recurrent syncope. The diagnostic evaluation and treatment proved to be difficult.