Catheter ablation of idiopathic ventricular tachycardia without the use of fluoroscopy.

Background: Catheter ablation is the treatment of choice for many patients with idiopathic ventricular tachycardia (VT). Unfortunately, conventional catheter ablation is guided by fluoroscopy, which is associated with a small but definite radiation risk for patients and laboratory personnel. The aim of our study is to assess feasibility, success rate and safety of idiopathic VT ablation procedure performed without the use of fluoroscopy.

Which is the best catheter to perform atrial fibrillation ablation? A comparison between standard ThermoCool, SmartTouch, and Surround Flow catheters.

Introduction: Catheter ablation (CA) is an established therapy for atrial fibrillation (AF). The SmartTouch catheter (STc) provides information about catheter tip to tissue contact force (CF). The Surround Flow catheter (SFc) provides a uniform cooling of the tip during ablation.

Catheter-tissue contact force for pulmonary veins isolation: a pilot multicentre study on effect on procedure and fluoroscopy time.

Aims: Catheter-tissue contact is critical for effective lesion creation in radiofrequency catheter ablation (RFCA). In a multicentre prospective study, we assessed the effect of direct contact force (CF) measurement on acute procedural parameters during RFCA of atrial fibrillation (AF).

Methods And Results: A new open-irrigated tip catheter with CF sensing (SmartTouch™, Biosense Webster Inc.

Impact of respiration on electroanatomical mapping of the right atrium: implication for cavotricuspid isthmus ablation.

Purpose: Cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFL) has become the preferred treatment for this arrhythmia. The aims of this study were to assess the impact of respiratory gating (RG) on electroanatomical mapping of CTI and to assess the efficiency of CTI ablation guided by the Carto3® system equipped with the new respiration gating software.

Methods: Forty-four consecutive patients (mean age, 60 ± 13 years; 25 male) undergoing cavotricuspid ablation for symptomatic common AFL were randomly assigned to CARTO™ mapping with or without enabling RG module (Group A, RG OFF, Group B, RG ON).

Catheter ablation of right atrial ganglionated plexi in patients with vagal paroxysmal atrial fibrillation.

Background: Catheter ablation of ganglionated plexi (GP) in the left atrium has been proposed in different subgroup of patients with atrial fibrillation (AF). Anatomic studies found a high prevalence of GP in the posterior surface of the right atrium (RA). Experimental data suggested the potential role of right atrial GP in the AF initiation and maintenance.

The new electroanatomical Carto3 mapping system: three-dimensional right ventricular fast anatomical map resolution in comparison to magnetic resonance image.

Three-dimensional mapping systems are required in some electrophysiological procedures in order to allow nonfluoroscopic catheter navigation, reconstruction of electrophysiological mechanisms, particularly of complex arrhythmias, and to facilitate catheter ablation. Accuracy in three-dimensional reconstructions of cardiac chambers is crucial to increase the effectiveness and safety of electrophysiological procedures. We report on the feasibility of the anatomical reconstruction of the right ventricular chamber by means of the new Carto3 system.

Integration of MR images with electroanatomical maps: feasibility and utility in guiding left ventricular substrate mapping.

Purpose: The purpose of the study is to evaluate the feasibility and utility of magnetic resonance (MR) image and electroanatomic (EA) maps integration in guiding detailed left ventricle (LV) anatomical and substrate mapping, identifying the most accurate registration strategy.

Methods: Twenty-five patients with dilated ischemic or non-ischemic cardiomyopathy were enrolled. We first verified the feasibility and accuracy of EA mapping and MR image integration using four different strategies (15 patients).

Noncompacted ventricular myocardium: characterization by intracardiac echo.

We report a patient with clinical manifestation of arrhythmias and evidence of noncompacted myocardium in both left and right ventricular apex. The diagnosis was made with intracardiac echo performed during the electrophysiologic study. This method has allowed the diagnosis of noncompaction of the ventricular myocardium due to its high resolution.

Pain perception during esophageal warming due to radiofrequency catheter ablation in the left atrium.

Purpose: We investigated the relationship among esophageal warming, pain perception, and the site of radiofrequency (RF) delivery in the left atrium (LA) during the course of catheter ablation of atrial fibrillation. Such a procedure in awake patients is often linked to the development of visceral pain and esophageal warming. As a consequence, potentially dangerous complications have been described.

Intracardiac echocardiography and electroanatomic mapping in diagnosis of arrhythmogenic right ventricular dysplasia.

A 48-year-old man with an episode of syncope and family history of sudden cardiac death was evaluated. The ECG showed negative T waves from V1 to V3 with evidence of epsilon-wave. Magnetic resonance imaging showed replacement with fibrofatty tissue in midapical regions of free wall of the right ventricle with dyskinesia.

Novel substituted aminoalkylguanidines as potential antihyperglycemic and food intake-reducing agents.

We report the synthesis and evaluation of aminoalkylguanidine analogues and derivatives in C57BL/KsJ db/db diabetic mice, following identification by random screening of 1a and 1b as potential antihyperglycemics and/or modulators of food intake. These compounds are related to galegine, a gamma,gamma-dimethylallylguanidine. Between the newly identified compounds, 1h N-(cyclopropylmethyl)- N'-(4-(aminomethyl)cyclohexylmethyl)guanidine showed the most balanced activity as antihyperglycemic and food intake-reducing agent.

L-carnitine inhibits a subset of platelet activation responses in chronic uraemia.

Background: Activated uraemic platelets expose the aminophospholipid phosphatidylserine (PS) at their outer surface, which generates a cell procoagulant phenotype and seems at least partly due to an increase in cell caspase-3 activity. L-carnitine (LC) may decrease surface-exposed PS in stored apheresis platelets and inhibit the activity of recombinant caspases, but its effects on platelet activation response with PS externalization have not been ascertained in chronic renal failure. In the present study, we investigated in vitro and in vivo the effects of LC on PS exposure in platelets from chronic uraemic patients.

Cellular properties of human erythrocytes preserved in saline-adenine-glucose-mannitol in the presence of L-carnitine.

L-Carnitine (LC) in the preservation medium during storage of red blood cells (RBC) can improve the mean 24-hr percent recovery in vivo and increase RBC life-span after reinfusion. The purpose of the study was to investigate the differences in the biochemical properties of RBCs stored in the presence or absence of LC, and the cell-age related responses to storage conditions and to LC. RBC concentrates in saline-adenine-glucose-mannitol (SAG-M) were stored in the presence or absence of 5 mM LC at 4 degrees C for up to 8 weeks.

Increased platelet phosphatidylserine exposure and caspase activation in chronic uremia.

Platelet activation is associated with exposure of the aminophospholipid phosphatidylserine (PS) to the outer hemi-leaflet of the plasma membrane bilayer, which seems to be involved in the coagulation process. Because platelet activation may occur in patients suffering from chronic uremia, which is frequently associated with a thrombophilic tendency, we studied whether uremic platelets show an increased propensity to expose PS on the outer membrane leaflet and whether this process is linked with important functional and molecular changes. Flow cytometric percentage of annexin V-positive platelets, a measure of PS externalization, was significantly elevated (P < 0.

Removal of uraemic plasma factor(s) using different dialysis modalities reduces phosphatidylserine exposure in red blood cells.

Background: Solute(s) retained during uraemia cause increased exposure of aminophospholipid phosphatidylserine (PS) on the outer surface of erythrocyte membranes, and this phenomenon may be involved in the pathophysiology of uraemia by promoting abnormal erythrocyte interactions.

Methods: We examined in a prospective randomized cross-over fashion the ability of various dialysis modalities to remove the circulating uraemic factor(s) causing increased PS externalization in red cells. Each patient was treated with haemodialysis (HD) and with on-line haemodiafiltration (HDF) using standard high-flux polysulphone membranes or with the new polisulphone-based Helixone membrane to compare the effects of dialysis technique and membrane type on PS exposure.

Participation of carnitine palmitoyltransferase in the synthesis of dipalmitoylphosphatidylcholine in rat alveolar type II cells.

We have investigated the role of carnitine palmitoyltransferase (EC 2.3.1.

L-carnitine decreases glycolysis in liquid-stored platelets.

Background: The platelet storage lesion is characterized metabolically by a pH decrease associated with lactic acid generation; a change in platelet morphology from discoid to spherical; a diminished response to in vitro challenge tests, such as the hypotonic shock response (HSR) and extent of shape change (ESC); increased surface P-selectin expression; and decreased in vivo recovery and survival. Altering storage conditions to improve these measures could allow for extension of the duration of in vitro storage.

Study Design And Methods: ABO-identical paired platelet concentrates were pooled and then equally divided into two plastic bags.

Increased erythrocyte phosphatidylserine exposure in chronic renal failure.

The appearance of phosphatidylserine, an aminophospholipid normally confined to the inner monolayer, at the outer leaflet of red cell membrane may have several pathophysiologic implications. This study examines erythrocyte phosphatidylserine exposure in chronic renal failure (CRF) patients on conservative treatment or on dialysis, to assess possible alterations to phospholipid asymmetry in a condition associated with a state of deranged red cell function. A significant increase in phosphatidylserine-expressing erythrocytes was found in undialyzed patients with CRF (2.

Addition of L-carnitine to additive solution-suspended red cells stored at 4 degrees C reduces in vitro hemolysis and improves in vivo viability.

Background: The role of L-carnitine (LC) as the requisite carrier of long-chain fatty acids into mitochondria is well established. Human red cells (RBCs), which lack mitochondria, possess a substantial amount of LC and its esters. In addition, carnitine palmitoyl transferase, an enzyme that catalyzes the reversible transfer of the acyl moiety from acyl-coenzyme A to LC is found in RBCs.

High performance liquid chromatography of long-chain acylcarnitine and phospholipids in fatty acid turnover studies.

In this paper we describe a rapid, isocratic high performance liquid chromatography (HPLC) method for the study of radioactive fatty acid incorporation into complex lipids of human erythrocytes, which allows the simultaneous separation of the major phospholipid classes and long-chain acylcarnitines. The lipid extract of erythrocytes pulsed with radioactive fatty acids was injected into an HPLC system equipped with a silica column. The individual components eluted were monitored by ultraviolet absorption and radioactive emission.

Effect of propionyl-L-carnitine treatment on membrane phospholipid fatty acid turnover in diabetic rat erythrocytes.

In this work we have examined the effect of the oral administration of propionyl-L-carnitine (PLC) on the membrane phospholipid fatty acid turnover of erythrocytes from streptozotocin-induced diabetic rats. A statistically significant reduction in radioactive palmitate, oleate, and linoleate, but not arachidonate, incorporation into membrane phosphatidylcholine (PC) of diabetic rat erythrocytes with respect to control animals was found. Changes in radioactive fatty acid incorporation were also found in diabetic red cell phosphatidylethanolamine (PE), though they were not statistically significant.

Effects of L-carnitine and its acetate and propionate esters on the molecular dynamics of human erythrocyte membrane.

EPR and fluorescence probes were used in this study to define the effects of L-carnitine and its short-chain esters, acetyl-L-carnitine and propionyl-L-carnitine, on the natural fluidity gradient and molecular packing of phospholipid headgroups of erythrocyte membrane in intact cells. Purified erythrocyte suspensions, labeled with different stearic acid derivatives containing a stable doxyl radical ring at the C-5, C-7, C-12 and C-16, were incubated with 0.5-5 mM L-carnitine and its esters for 60 min at 37 degrees C and washed twice with an isosmotic buffer.

Acyl-trafficking in membrane phospholipid fatty acid turnover: the transfer of fatty acid from the acyl-L-carnitine pool to membrane phospholipids in intact human erythrocytes.

In this work we have investigated the transfer of radioactive palmitic acid between membrane phospholipids and acyl-L-carnitines in intact human erythrocytes. During the incubation period of labeled erythrocyte in non-defatted bovine serum albumin, radioactivity in phosphatidylcholine and phosphatidylethanolamine increased. On the contrary, a decrease of radioactivity in erythrocyte palmitoyl-L-carnitine was observed.