Cardiac Autonomic Response to Active Standing in Adults With Vasovagal Syncope.

Purpose: Little is known about the autonomic response to active standing in vasovagal syncope, and most works have focused on children or adolescents. The aim of this work was to study the changes in cardiac autonomic modulation in adult patients with vasovagal syncope through heart rate variability analysis with linear and short-term complexity (alpha-1) indexes during supine position and active standing, in patients with positive or negative head-up tilt test (HUTT).

Methods: Twenty-five patients with vasovagal syncope were included.

Simplified progressive approach for the ablation of scar related atrial macroreentrant tachycardias.

Introduction: Radiofrequency ablation of scar related right atrial flutter is challenging. Long procedures, prolonged fluoroscopic times and high percentages of recurrences are of concern. We present a simple and progressive approach based on a single electroanatomic map of the right atrium.

Efficacy and safety of apixaban in patients after cardioversion for atrial fibrillation: insights from the ARISTOTLE Trial (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation).

Objectives: The aim of this study was to determine the risk of major clinical and thromboembolic events after cardioversion for atrial fibrillation in subjects treated with apixaban, an oral factor Xa inhibitor, compared with warfarin.

Background: In patients with atrial fibrillation, thromboembolic events may occur after cardioversion. This risk is lowered with vitamin K antagonists and dabigatran.

Prevalence of fibromyalgia in vasovagal syncope.

Background: Vasovagal syncope is an acute manifestation of autonomic nervous system dysfunction. This type of syncope is often associated with other dysautonomic expressions such as migraine, gastroparesis, or postural tachycardia syndrome. Autonomic nervous system dysfunction has been proposed as a key element in the pathogenesis of fibromyalgia.

Apixaban versus warfarin in patients with atrial fibrillation.

Background: Vitamin K antagonists are highly effective in preventing stroke in patients with atrial fibrillation but have several limitations. Apixaban is a novel oral direct factor Xa inhibitor that has been shown to reduce the risk of stroke in a similar population in comparison with aspirin.

Methods: In this randomized, double-blind trial, we compared apixaban (at a dose of 5 mg twice daily) with warfarin (target international normalized ratio, 2.

[Genetic study of the vasovagal syncope associated to the Arg389Gly polymorphism of the beta1 adrenergic receptor].

The purpose of this study was to evaluate the correlation between the vasovagal syncope (VVS) and the beta1 adrenergic receptor polymorphism at the 389 position. Seventy individuals with VVS were selected. DNA was extracted from peripheral blood by salting out and subjected to the amplification-restriction test.

Personal exposure to PM2.5 air pollution and heart rate variability in subjects with positive or negative head-up tilt test.

Particulate matter air pollution has been related to an increase in cardiopulmonary morbidity and mortality especially in susceptible subjects with a known cardiopulmonary disease. Recent studies suggest that PM(2.5) air pollution was associated with changes in heart rate variability (HRV).

Value of symptoms to predict tilt testing outcome in patients with clinical suspicion of vasovagal syncope.

Studies to assess the value of clinical symptoms to predict the head-up tilt test (HUT) outcome in patients with suspicion of vasovagal syncope have shown controversial results. We undertook this study to compare the frequency of symptoms between subjects with and without history of syncope, its association with syncopal spells in those with a history of syncope and positive or negative HUT, and to identify clinical predictors of HUT outcome. Sixty seven subjects with a history of unexplained syncope and 26 subjects without a history of syncope were interviewed using a structured questionnaire before undergoing HUT, which was performed first in a passive phase and, if negative, was repeated with pharmacological challenge using 5 mg of sublingual isosorbide.

The Arg389Gly beta1-adrenergic receptor gene polymorphism and susceptibility to faint during head-up tilt test.

Aims: To investigate the association of the Gly389 allele with positive head-up tilt test (HUT) in a Mexican Mestizo population.

Methods And Results: HUT results were compared between carriers (one or two copies of the Gly389 allele) and non-carriers (Arg389Arg genotype) of the Gly389 allele of the beta(1)AR gene in 50 patients with unexplained syncope. Thirty-three patients (66%) had a positive HUT.

Ionic basis of pharmacological therapy in Brugada syndrome.

An implantable cardioverter-defibrillator is considered the only effective therapy to terminate ventricular arrhythmias in symptomatic patients with Brugada syndrome. However, it does not prevent future arrhythmic episodes. Only antiarrhythmic drug therapy can prevent them.

Non-invasive assessment of endothelial function. Intra and inter-observer variability.

Background And Objectives: Non-invasive evaluation of endothelial function with high resolution ultrasound has become a widely accepted tool in determination of high risk subjects for early atherosclerosis. Despite its simple appearance, ultrasonographic assessment of brachial artery changes, is technically challenging and has a significant learning curve. In the present study, we evaluate the intra and inter-observer variability in assessing peripheral endothelial function with high resolution ultrasound at a tertiary referral center.

[Differences in cardiac autonomic modulation between women and men].

Gender differences in cardiac autonomic modulation are a controversial topic in several studies. The aim of this study, was to describe and compare the heart rate variability in 30 women and 20 men, Mexicans, between 21 to 36 years of age. A 20 to 24 hours Holter monitoring was performed in all of them.

Cerebrovascular blood flow during the near syncopal phase of head-up tilt test: a comparative study in different types of neurally mediated syncope.

Aims: This study analyses the changes in cerebral blood flow (CBF) velocity occurring in the near syncopal phase of head-up tilt test (HUT) to determine whether their appearance during the premonitory symptoms permits the differentiation of the different types of haemodynamic response.

Methods And Results: Six hundred and nineteen patients aged 35.9 +/- 16.

Drug therapy in Brugada syndrome.

Sudden cardiac death in healthy individuals with structurally normal hearts and a characteristic morphology of the QRS complex resembling a right bundle branch block with elevation of the ST segment in V1 to V3 is known as Brugada syndrome (BrS). Although placement of an implantable cardioverter-defibrillator is considered the only effective therapy for symptomatic patients, some authors have repeatedly reported a beneficial effect of quinidine and isoproterenol in patients with BrS. Also, isolated case reports on the usefulness of cilostazol, sotalol, and mexiletine have been described.

Neurocardiogenic syncope in chronic atrioventricular block.

We report a 37-year-old man with type I second-degree atrioventricular (AV) block (atypical Wenckebach's periodicity) referred to our department for pacemaker implantation because of an episode of syncope. After exhaustive evaluation, including electrophysiological test, in which Wenckebach's cycles with block within the AV node was demonstrated, syncope was considered to be neurally mediated. Head-up tilt testing with sublingual isosorbide dinitrate was positive.

Ambient fine particles modify heart rate variability in young healthy adults.

Particulate air pollution has been related with cardiopulmonary morbidity and mortality. Recent studies have shown that an increase in particulate matter (PM)(2.5) ambient concentrations was associated with a decrease in heart rate variability (HRV) in the elderly with cardiovascular conditions, which could increase the risk of death.

Arrhythmic storm responsive to quinidine in a patient with Brugada syndrome and vasovagal syncope.

A 37-year-old man with Brugada syndrome (BrS) and arrhythmic storm is described. One month after implantation of a cardioverter-defibrillator he presented with recurrent appropriate shocks for spontaneous ventricular fibrillation (VF). Because of this arrhythmic storm, quinidine therapy was initiated with total suppression of all spontaneous arrhythmias.

Familial vasovagal syncope.

Vasovagal syncope (VVS) is a common clinical problem characterized by transient episodes of loss of consciousness due to abnormal autonomic activity. This paper describes two groups of monozygotic twins, from different families, affected by VVS and a family with several members with this condition. Their clinical characteristics, haemodynamic response to tilt, treatment, and outcome are described.

Age, body mass index, and menstrual cycle influence young women's heart rate variability --a multivariable analysis.

Heart rate variability (HRV) in women has been related independently to endogenous sex hormones, hormone replacement therapy, menopause, menstrual cycle, body mass index (BMI), and physical conditioning. However, the joint influence of all these factors has not been reported. The present study describes the relation between circadian variation HRV and assesses its association with BMI, age, and menstrual cycle in healthy young women.

Dynamic electrocardiographic changes after aborted sudden death in a patient with Brugada syndrome and rate-dependent right bundle branch block.

A 37-year-old man with Brugada syndrome and dynamic changes of the ST-segment morphology observed after an episode of aborted sudden death is described. On admission, after 3 syncopal episodes during nighttime, his electrocardiogram showed right bundle branch block (RBBB) with a J-point elevation of 0.6 mV in lead V 2 .