About this Research Topic
Syncope, sudden and transient loss of consciousness due to circulatory collapse is a frequent medical emergency and a substantial diagnostic challenge for many. Between 1-2% of all admissions to emergency departments worldwide are due to syncope, and up to 30-40% of all people faint at least once during their lifetime. The three main syncope aetiologies are autonomically mediated abnormal cardiovascular reflexes, amongst which vasovagal is the most prevalent, autonomic dysfunction resulting in orthostatic hypotension, and primary heart and great vessels diseases. Of the latter, cardiac arrhythmias are predominantly involved in cardiac syncope, other causes being less frequent.
Important advances in syncope diagnosis, such as introduction of provocation tests, especially head-up tilt with continuous non-invasive haemodynamic monitoring, and implantable/insertable cardiac monitors allowed better understanding of syncope pathophysiology. Moreover, studies on cardiovascular neurohormones revealed basic neuroendocrine interactions underlying circulatory collapse leading to syncope.
There is a broad consensus that three most important aspects of syncope evaluation and management are initial risk stratification, further workup based on pre-test probability, and application of more advanced diagnostic modalities under supervision of specially trained syncope experts.
Prognosis in cardiac syncope is much worse than in reflex-mediated conditions. However, the poor prognosis in autonomic failure (orthostatic hypotension) cannot be neglected implying a systematic approach to patients with unexplained syncope, especially in older populations is crucial.
Today, there are very potent and effective treatment options available for syncope associated with cardiac arrhythmias, such as pacemakers, implantable cardioverter/defibrillators, invasive electrophysiological procedures and pharmacological agents. On the other hand, there are only few procedures and agents effective against the most prevalent forms of syncope associated with autonomic dysfunction, abnormal reflexes and autonomic failure. This is a huge challenge for tomorrow and apart from systematic approach to syncope management, this Research Topic will discuss new directions and recent achievements in the field of syncope research.
Keywords: Reflex Syncope, Vasovagal Syncope, Neuroendocrine Role in Syncope, Prognosis of Syncope, Therapy of Syncope