Assessment of systolic ejection time as a hemodynamic marker of incipient bradycardic vasovagal syncope. A pilot study.

Background: Detection of markers of incipient syncope in patients with vasovagal syncope (VVS), without prodromal symptom, is still an open issue. The aim of this study was to assess the behavior of heart rate (HR) and ejection time, expressed as the percentage of the corresponding cardiac cycle (ET%), in patients with bradycardic VVS with a view to providing an alarm before the event.

Methods: In 33 patients with syncope and positive tilt testing and in 33 control patients, we collected beat-to-beat data on HR, ET%, stroke volume (SV), and blood pressure (BP).

Do subjects with vasovagal syncope have subtle haemodynamic alterations during orthostatic stress?

Aims: There are conflicting reports on the presence of subtle haemodynamic alterations during orthostatic stress in subjects with vasovagal syncope (VVS). The aim of the present study was to investigate whether young/middle-aged subjects with VVS show abnormal responses to orthostatic stress.

Methods And Results: Four groups of subjects underwent tilt testing (TT) during the passive phase and, if negative, after nitroglycerin administration: Group I, 20 subjects with a history of syncope and positive passive TT; Group II, 23 subjects with a history of syncope and TT positive after nitroglycerin; Group III, 23 subjects with a history of syncope and negative TT; and Group IV, 20 normal control subjects.

Current treatment of recurrent vasovagal syncope: between evidence-based therapy and common sense.

Vasovagal syncope is very frequent and benign and the vast majority of subjects do not need any specific treatment, but only reassurance and education. An unknown but small percentage of patients require specific treatment when syncope is very frequent or is responsible for major trauma. For these patients, there are some evidence-based therapies available and some first-line treatments appear to be established.

The venous system is the main determinant of hypotension in patients with vasovagal syncope.

Aims: In patients with vasovagal syncope (VVS), a neural reflex appears the main determinant of hypotension leading to loss of consciousness; whether hypotension is mainly due to involvement of the arterial system or the venous system remains a debated issue. The aim of the present study was to assess which of these two systems is responsible for the fall in blood pressure (BP) in patients with VVS; to this end, a haemodynamic study was carried out not only before and during loss of consciousness but also during the recovery phase.

Methods And Results: Beat-to-beat recordings of heart rate (HR), BP (volume-clamp method) and stroke volume (SV) (modelflow method), cardiac output (CO), and total peripheral resistance (TPR) were made at rest, during unmedicated tilt testing (TT) and recovery from loss of consciousness in 18 patients with a history of syncope (age 45+/-23 years) and positive response to TT.

Efficacy of tilt training in the treatment of neurally mediated syncope. A randomized study.

Recurrent neurally mediated syncope represents a common clinical event and a therapeutic challenge. Recently tilt training has been proposed for the treatment of recurrent neurally mediated syncope. To evaluate the efficacy of tilt training in preventing tilt-induced syncope and its feasibility, this controlled, randomized study was undertaken.

Clinical spectrum of neurally mediated reflex syncopes.

Aims: The clinical features of the various types of neurally mediated reflex syncope have not been systematically investigated and compared. We sought to assess and compare the clinical spectrum of neurally mediated reflex syncopes.

Methods And Results: Four hundred sixty-one patients with syncope were prospectively evaluated and 280 had neurally mediated reflex syncope.

Plasma galanin response to head-up tilt in normal subjects and patients with recurrent vasovagal syncope.

Neurohumoral factors may contribute to cardiovascular changes associated with vasovagal syncope (VVS). Galanin (GAL) is a neuropeptide, widely distributed in the central and peripheral nervous systems, that interacts with both sympathetic and vagal systems as well as with neurotransmitters, such as serotonin. We investigated the changes in plasma GAL and catecholamine levels during head-up tilt (HUT) test in patients with recurrent VVS.

Mechanism of syncope in patients with positive adenosine triphosphate tests.

Objectives: We prospectively evaluated the mechanism of syncope in patients with positive adenosine triphosphate (ATP) tests (defined as the induction of atrioventricular [AV] block with a ventricular pause >/=6 s after an intravenous bolus of 20 mg ATP).

Background: Patients with unexplained syncope tend to have more positive ATP tests results than those without syncope.

Methods: An implantable loop recorder (ILR) was inserted in 36 ATP-positive patients (69 +/- 10 years; 22 women; median of 6 syncopal episodes); 15 of them also had a positive response to tilt testing.