In this edition of Circulation, Spirito and coworkers present a retrospective study of a large cohort of patients with hypertrophic cardiomyopathy in which they compare the prognostic significance of neurally mediated (vasovagal) faints and unexplained syncope.1 Although neither symptom was significantly associated with sudden-death risk, subgroup analysis revealed that unexplained syncope was ...

Vasovagal or neurocardiogenic syncope is the most common form of reflex syncope. In this case, the final syncope mechanism is the sudden shut-down of the autonomic nervous system to maintain the minimum blood pressure and heart rate for proper cerebral perfusion. The prognostic outlook for patients with vasovagal syncope is usually favourable, but a patient subgroup presents episodes that are a...

AIM To evaluate the possible relation between adenosine sensitive syncope and tilt induced vasovagal syncope. METHODS An ATP test and a head up tilt test were performed in 175 consecutive patients with syncope of uncertain origin. The ATP test consisted of the rapid intravenous injection of 20 mg of ATP; a positive response was defined as the induction of a ventricular pause (maximum RR inter...

During standing, both the position of the cerebral circulation and the reductions in mean arterial pressure (MAP) and cardiac output challenge cerebral autoregulatory (CA) mechanisms. Syncope is most often associated with the upright position and can be provoked by any condition that jeopardizes cerebral blood flow (CBF) and regional cerebral tissue oxygenation (cO(2)Hb). Reflex (vasovagal) res...

OBJECTIVE The G protein is responsible for signal intracellular transduction and participates in cardiovascular reflexes. C825T polymorphism of the gene encodes the B3 subunit of G protein (GNB3) and causes the increased intracellular signal transduction. The aim was the evaluation GNB3 C825T polymorphism manifestation in vasovagal patients with no other diseases. METHODS In 68 positive tilte...

The ESC guidelines on syncope were published in 2001 and updated in 2004. Adherence to the recommendations enables early stratification of low and high risk patients and prevents unnecessary investigations and admissions. Vasovagal syncope (VVS) is the commonest cause of syncope in all age groups and a low risk condition. The study objective was to determine whether the ESC guidelines were adhe...

A 30 year old woman with a lifelong history of severe, recurrent, vasovagal syncope became asystolic for 30 seconds after 37 minutes of 60 degrees head-up tilt. During early tilt, sympathetic activity, heart rate, left ventricular contractility, and cardiac output increased. Mean blood pressure was initially maintained. Presyncope was associated with maximal contractility and bradycardia despit...