Examinations in suspected vasovagal syncope

Abstract

The purpose of this chapter is to provide a comprehensive and accurate guide to the clinician in order to choose the best test or test battery for a patient with a suspected vasovagal syncope (VVS), either typical or nontypical. The European Society of Cardiology Guidelines ensure a methodical and rational approach to patients with syncope and aid in choosing the right patient for the right test. Detailed autonomic clinical history and physical examination are the essentials for the individualized selection of appropriate autonomic tests. Together with the precise acknowledgment of what information a test can or cannot provide, a pragmatic approach, based on the pretest probability inferred from the initial examination, would assure the use of appropriate tests and avoidance of those inappropriate with a consequential improvement of sensitivity and specificity, diagnostic accuracy, and cost savings. We recommend a tailored algorithm for each patient. The coexistence of different neurally mediated mechanisms in the genesis of syncope, in particular in older people, pushes toward a complete autonomic and cardiovascular evaluation in every patient without stopping at the first apparent diagnosis. On the whole, the employed tests would suggest a more precise diagnosis together with the underlying mechanisms. In addition, in some cases, tests, in particular the Tilt Table Test, can help patients to better recognize their own symptoms (e.g., prodromes) and can be useful to evaluate the adequacy and impact of therapeutic measurements. We classify the tests of autonomic function according to the final organ response to be evaluated: (1) tests that integrate the evaluation of blood pressure and heart rate; (2) tests that predominantly evaluate heart rate; (3) tests that predominantly evaluate blood pressure.