Pathophysiology of Syncope:Current Concepts and Their Development.

Syncope is a symptom in which transient loss of consciousness occurs as a consequence of a self-limited, spontaneously-terminating, period of cerebral hypoperfusion. Many circulatory disturbances (e.g. brady- or tachyarrhythmias, reflex cardioinhibition-vasodepression-hypotension) may trigger a syncope or near-syncope episode, and identifying the cause(s) is often challenging. Some syncope may involve multiple etiologies operating in concert, whereas in other cases multiple syncope events may be due to various differing causes at different times. In this communication we address current understanding of the principal contributors to syncope pathophysiology including examination of the manner in which concepts evolved, and an overview of factors that constitute consciousness and loss of consciousness, and aspects of neural-vascular control and communication that are impacted by cerebral hypo perfusion leading to syncope . Emphasis focuses on: 1) current understanding of the way transient systemic hypotension impacts brain blood flow and brain function, 2) the complexity and temporal sequence of vascular, humoral and cardiac factors that may accompany the most common causes of syncope, 3) the range of circumstances and disease states that may lead to syncope, and 4) clinical features associated with syncope and in particular the reflex syncope syndromes.

Cardioneuroablation for the treatment of reflex syncope and functional bradyarrhythmias. A Scientific Statement of the European Heart Rhythm Association (EHRA) of the ESC, the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS) and the Latin American Heart Rhythm Society (LAHRS).

Cardioneuroablation has emerged as a potential alternative to cardiac pacing in selected cases with vasovagal reflex syncope, extrinsic vagally induced sinus bradycardia-arrest or atrioventricular block. The technique was first introduced decades ago, and its use has risen over the past decade. However, as with any intervention, proper patient selection and technique are a prerequisite for a safe and effective use of cardioneuroablation therapy. This document aims to review and interpret available scientific evidence and provide a summary position on the topic.

Making certain that noninvasive therapy for vasovagal syncope has failed before proceeding to invasive interventions.

There is a perceived need to express concisely the advice of guidelines in the context of consideration of invasive management of highly symptomatic vasovagal syncope. In response to this need the table is presented as a checklist and the text adds explanation and details. It is anticipated that this will prove to be of value for clinicians.