Dionyssios Leftheriotis

National and Kapodistrian University of Athens | uoa · Division of Cardiology I

Background: In 2008, the radiofrequency ablation (RFA) procedures registry of the Hellenic Society of Cardiology was created. This online database allowed electrophysiologists around the country to input data for all performed ablation procedures. The aim of this study is to provide a thorough report and interpretation of the data submitted to the...

Background: Noninvasive risk stratification aims to detect abnormalities in the pathophysiological mechanisms underlying ventricular arrhythmias. We studied the predictive value of repeating risk stratification in patients with an implantable cardioverter-defibrillator (ICD). Methods: The EUTrigTreat clinical study was a prospective multicenter tri...

Background Prediction of sudden cardiac death in heart failure (HF) remains suboptimal. Blood levels of the S100A8/A9 heterodimer protein complex and the soluble receptor of advanced glucation end product (sRAGE) are promising biomarkers in HF, reflecting inflammatory/fibrotic and apoptotic pathways, possibly involved in ventricular arrhythmogenesi...

Introduction Glycemic control reflected by glycated hemoglobin (HbA1c) is regarded as a risk factor and a strong predictor of mortality in patients with heart failure (HF). Hyperglycemia may contribute to oxidative stress, endotelial dysfunction and cardiac fibrosis and influence negatively heart failure prognosis in patients with or without diabet...

Treatment of left ventricular outflow tract (LVOT) obstruction in hypertrophic obstructive cardiomyopathy (HOCM) with septal reduction, either with myectomy or alcohol septal ablation, is aiming to reduce the LVOT gradient and improve symptoms in patients who are refractory to or do not tolerate medical treatment. Apart from contributing to the evo...

Background-Aim: T-wave alternans (TWA), defined as a beat-to-beat fluctuation in ST- segment or T- wave morphology, has emerged as a useful electrocardiographic (ECG) marker of risk for cardiovascular mortality and sudden cardiac death (SCD). The 2 most extensively studied techniques are i) the Spectral, assessed as negative or not, and the ii) the...

Background and purpose: Vasovagal syncope (VVS) is linked to more than one pathophysiologic mechanisms. Copeptin, an emerging cardiovascular marker, is a surrogate for arginine-vasopressin, which increases following VVS. We aimed to assess the dynamic pattern of copeptin levels in typical VVS, categorized by the degree of vasoconstriction during o...

Aims The optimal medical therapy of patients with vasovagal syncope (VVS) remains controversial. Fluoxetine is effective against anxiety and panic disorders, while its use has shown promising results for VVS. Anxiety sensitivity is a personality trait observed in a considerable proportion of patients with VVS, associated with predisposition to anxi...

Introduction Pacemaker implantation is a minimally invasive technique performed under fluoroscopic guidance. Purpose This study aims to compare effective dose (ED) delivered to patients at pacemaker implantation procedures by two angiographic systems of different image capture technology; one with flat panel detector (FPD) and one with image inten...

Background: In experimental models, stellate ganglion block (SGB) reduces the induction of atrial fibrillation (AF), while data in humans are limited. Objective: In this study, we assessed the effect of unilateral SGB on atrial electrophysiologic properties and AF induction, in patients with paroxysmal AF. Methods: Thirty-six patients with par...

Although transient sinus arrest has been reported during pulmonary-vein isolation (PVI), the long-term impairment of sinus node following PVI has not been described. In this report, we present a case of sinus node dysfunction necessitating a permanent pacemaker, caused during PVI. Clinical data, intracardiac electrograms, and cardiac imaging were i...

The impact of ranolazine, an anti-ishemic agent with antiarrhythmic properties, on paroxysmal atrial fibrillation (PAF) in patients with coronary artery disease (CAD) remains unclear. Pacing devices can be useful tools for disclosing even asymptomatic PAF. Purpose of this study is to assess the effect of ranolazine on atrial fibrillation (AF), in p...

Ranolazine is a relatively novel antiischemic/antianginal compound with antiarrhythmic properties. We investigated its ability to shorten the time to conversion of postoperative atrial fibrillation (POAF) when added to amiodarone after coronary artery bypass graft (CABG) surgery. In this prospective, randomized, allocation-concealed, single-blind,...

Purpose: The impact of ranolazine, an anti-ishemic agent with antiarrhythmic properties, on Paroxysmal Atrial Fibrillation (PAF) in patients with Coronary Artery Disease (CAD) remains unclear. Pacing devices can be useful tools for disclosing even asymptomatic PAF. Purpose of this study is to assess the effect of ranolazine on atrial fibrillation (...

Purpose: The Selvester score translates subtle changes in ventricular depolarization measured by the electrocardiogram (ECG) into information about myocardial scar location and size, with a high degree of concordance with autopsy and MRI-measured findings. It has recently been shown that this score enhances prediction of which patients will experie...

Purpose: The arginine-vasopressin (AVP) system is one of the main blood pressure regulating systems. Copeptin is a stable and sensitive surrogate marker for AVP release. Vasovagal syncope (VVS) is the most common type of syncope. The purpose of this study was to assess copeptin, as a marker of AVP system responsiveness, in patients (pts) with VVS d...

Objectives: Hemodialysis patients have a cardiovascular mortality rate of 20-40 times that of the general population. Aldosterone inhibition by spironolactone has exerted beneficial, prognostically significant cardiovascular effects in patients with heart failure maintained on hemodialysis or peritoneal dialysis. Our aim was to investigate spirono...

Pathologic collagen remodeling has been involved in the occurrence of ventricular arrhythmias and sudden cardiac death in heart failure. The aim of the study was to investigate the relationship between malignant ventricular arrhythmias and cardiac collagen turnover indexes, expressing specific types of derangement in collagen physiology, in stable...

The multi-electrode ablation catheter PVAC is used to simplify pulmonary vein isolation in patients undergoing ablation of atrial fibrillation. The use of the PVAC in cases of atrial tachycardia has not been reported before. In the present report, we present the use of the PVAC for the ablation of a left atrial tachycardia following pulmonary vein...

Pulmonary vein isolation has become the cornerstone of ablation for atrial fibrillation. However, it is sometimes followed by the development of left atrial macro-reentrant tachycardia. There is evidence to suggest that the myocardial sleeves within the pulmonary veins may be implicated in the mechanism of the tachycardia. Here we present a case of...

Purpose: Experimental studies showed that local capture of atrial fibrillation (AF) by rapid pacing was possible in humans. However, contradictory observations were reported on its effect at distant atrial sites. The present model-based study investigated the effect of rapid pacing on the paced and the non-paced atria. Methods: A biophysical model...

Selective serotonin re-uptake inhibitors (SSRIs) have been associated with better psychiatric status, functional capacity, and fewer arrhythmias in depressive patients with heart failure (HF). In this study, we tested the impact of sertraline (an SSRI) on patients with HF, but not clinical depression. We studied 62 clinically stable, nondepressive...

Background: Pulmonary vein isolation (PVI) is an established treatment option for patients with drug refractory paroxysmal atrial fibrillation. A novel compliant endoscopic ablation system housing a 980-nm-diode laser allows for discrete point-by-point ablation enabling a true circumferential ablation line design. We sought to determine the feasib...

Nonrandomized studies suggest a survival benefit for patients with atrial fibrillation (AF) undergoing catheter ablation compared with antiarrhythmic drug (AAD) therapy. Data from randomized trials are lacking. We performed a meta-analysis on mortality in randomized controlled trials comparing AF ablation with AADs. Pubmed, the Cochrane Central Reg...

Although there is evidence that inflammation and oxidative stress might contribute to the pathogenesis of atrial fibrillation (AF), the predictive value of inflammatory and oxidative stress markers in patients with AF has not been fully assessed. The aim of this study is to evaluate these markers as predictors of sinus rhythm (SR) maintenance, in p...

Severe hyperkalaemia is a life threatening electrolyte abnormality that if not treated urgently, might cause electric death. Hyperkalaemia induced electrocardiogram (ECG) alterations vary according to the levels and rate of increase of potassium concentration ([K(+)]) in the extracellular milieu but the paradox is that not all these cases provide E...

To compare the responses between clomipramine, a centrally acting substance, and nitroglycerin, with mainly peripheral action, when each drug is used during tilt test for the induction of vasovagal syncope (VVS). Hundred patients with recurrent episodes of classical VVS underwent two tilt tests in a randomized sequence. One test included 20 min of...

Right ventricular (RV) apical pacing deteriorates left ventricular (LV) function. RV nonoutflow (low) septal pacing may better preserve ventricular performance, but this has not been systematically tested. Our aim was to assess (1) whether long-term RV lower septal pacing is superior to RV apical pacing regarding LV volumes and ejection fraction (E...

Adjunctive interventions protect from reperfusion injury during primary percutaneous coronary intervention (PCI), but it is not known whether they are also protective during elective PCI. We sought to assess the efficacy of staccato reperfusion (SR) during PCI. Thirty seven patients with recent acute coronary syndrome and target lesions of 85-100%...

Abnormal (increased, but also decreased) vasodilative responses have been observed in patients with vasovagal syncope (VVS). The objective was to assess reactive vasodilation in supine patients with VVS and its relation to severity of the syndrome. Reactive vasodilation was also assessed after a simple therapeutic intervention (water drinking). Thi...

A high prevalence of minor psychiatric disorders (MPDs) has been reported in patients with vasovagal syncope (VVS). However, the relationship between the psychiatric substrate and syncope remains unclear. In order to test the hypothesis that MPDs may predispose to VVS, we assessed the prevalence of syncope, the response to head-up tilt test (HUTT)...

Heart rate turbulence (HRT) following isolated premature complexes is a baroreceptor-mediated prognostic marker. Short runs of spontaneous, nonsustained ventricular tachycardia (nsVT) exert a greater hemodynamic effect than extrasystoles and may trigger a more potent turbulence-like response (HRT(VT)), possibly related to other risk-related markers...

Positive inotropes used for the treatment of heart failure have been arrhythmogenic. Levosimendan is a novel calcium sensitizer with vasodilating properties and a complex mechanism of action. Its effect on ventricular arrhythmias and 24-hour Holter electrocardiographically derived prognostic autonomic nervous system-related markers, because it occu...

Novel imaging techniques reveal the aetiology of a pseudoinfarction ECG pattern A 64-year-old patient complaining of chest discomfort with an ECG compatible to myocardial infarction (panel A) was admitted to the cardiologic department with the diagnosis of acute coronary syndrome. Myocardial enzymes were within normal range throughout hospitalisa-t...

To compare the therapeutic efficacy of placebo, propranolol, and fluoxetine in patients with vasovagal syncope (VVS). Ninety-six consecutive patients with VVS were randomized to treatment with placebo, propranolol, or fluoxetine and followed-up for 6 months. Before and during treatment, they reported their syncopal and presyncopal episodes and grad...

Cardiac resynchronization therapy (CRT) pacing has been proposed as an additional treatment to medical therapy to improve heart failure patients with left ventricular asynchrony. The aim of this study was to evaluate the influence of CRT treatment on proinflammatory cytokines in patients with heart failure. Twenty patients, with a mean age 64 +/- 2...

Stimulation of atrial 5-HT4 receptors is associated with arrhythmias. Their blockade prolongs atrial effective refractory period (ERP), following short runs of atrial fibrillation (AF). The role of 5-HT4 receptors during longer periods of AF is unknown. In this study, we investigated the effects of the selective 5-HT4 receptor stimulation and block...

Among sequential patients with neurally-mediated syncope, we studied the response to head-up tilt test (HUTT) in patients with situational syncope (SS) and their follow-up. Our findings were compared to those in patients with vasovagal syncope (VVS). The response to HUTT in patients with SS has not to date been fully investigated. Additionally, the...

Introduction: Pulmonary veins have been found to play an important role in generating paroxysmal atrial fibrillation. Ablation of arrhythmogenic pulmonary veins appears to be one of the approaches to cure lone atrial fibrillation, when antiarrhythmic drugs have been proven to be ineffective. The purpose of this study was to describe our experience...

Introduction: Occurrence of ventricular pause of more than 6 seconds following administration of 20 mg b&s of intravenous adenosine (ATP test) has been observed in a relatively high percentage of patients (pts) with unexplained syncope. However, these results have been reported in a relatively limited number of pts in only 2 series. The aim of OUT...

This case report describes a patient with a history of neurocardiogenic syncope, who had had a negative head-up tilt test with isoprenaline, but he experienced a prolonged asystole during a head-up tilt test with clomipramine (serotonin reuptake inhibitor) 24 h later. This patient was successfully treated with fluoxetine.

Selective endothelin receptor-A antagonists are a promising new treatment in patients with heart failure and/or pulmonary hypertension. Animal studies have suggested that these agents may have additional cardiac electrophysiologic actions, however, no data exist in man. We examined the effects of acute endothelin receptor-A blockade on the sinus no...

The aim of the study was to randomly compare clomipramine, used as a challenge-agent during head-up tilt test, with isoproterenol, used in the conventional test, in patients with vasovagal syndrome. The serotonergic re-uptake inhibitor clomipramine was infused (5mg in 5min) at the start of head-up tilt test (Clom-HUT) in 126 patients (mean age 41+/...

Biventricular pacing is emerging as a long-term therapy for symptomatic heart failure. Analysis of heart rate variability (HRV) has become an important predictive tool in this syndrome. To assess whether chronic resynchronization therapy can affect HRV in patients with heart failure. Thirteen patients with heart failure were studied (mean age+/-1 S...

Although there are many studies concerning the effects of long-term oestrogen administration on systemic haemodynamics in postmenopausal women, the effects of oestrogen in patients with chronic heart failure are not defined. The goal of this study was to ev