Catheter-induced mechanical trauma to fast and slow pathways during radiofrequency ablation of atrioventricular nodal reentry tachycardia: incidence, predictors, and clinical implications.

Background: Data on the incidence and significance of catheter-induced trauma to fast and slow pathways are scarce.

Objectives: To evaluate the incidence, predictors, and clinical implications of inadvertent catheter-induced mechanical trauma to fast and slow pathways during radiofrequency ablation (RFA) of atrioventricular nodal reentry tachycardia (AVNRT).

Methods: A total of 901 consecutive patients (aged 9-92 years old) with inducible sustained AVNRT underwent RFA of the slow pathway.

The morphology of the QT interval predicts torsade de pointes during acquired bradyarrhythmias.

Objectives: The purpose of this study was to define the electrocardiographic (ECG) predictors of torsade de pointes (TdP) during acquired bradyarrhythmias.

Background: Complete atrioventricular block (CAVB) might lead to downregulation of potassium channels, QT interval prolongation, and TdP. Because potassium-channel malfunction causes characteristic T-wave abnormalities in the congenital long QT syndrome (LQTS), we reasoned that T-wave abnormalities like those described in the congenital LQTS would identify patients at risk for TdP during acquired bradyarrhythmias.

Radiofrequency ablation of atrioventricular nodal reentry tachycardia: a 14 year experience with 901 patients at the Tel Aviv Sourasky Medical Center.

Background: Atrioventricular nodal reentry tachycardia is the most frequent cause of regular, paroxysmal supraventricular tachycardia. Radiofrequency ablation of the slow pathway has been recommended as first-line therapy for curing AVNRT.

Objectives: To report a 14 year experience of RFA of the slow pathway in patients with AVNRT treated in our laboratory.

Effects of losartan + L-arginine on nitric oxide production, endothelial cell function, and hemodynamic variables in patients with heart failure secondary to coronary heart disease.

The purpose of the present study was to evaluate the effects of losartan and the combination of losartan and L-arginine on endothelial function and hemodynamic variables in patients with heart failure (HF). Endothelium-dependent vasodilation is impaired in patients with HF. It was hypothesized that the administration of losartan and the combination of losartan and L-arginine might increase nitric oxide production and have a beneficial additive effect on endothelial function and hemodynamic variables in patients with HF.

Long-term effects of dual-chamber pacing with periodic echocardiographic evaluation of optimal atrioventricular delay in patients with hypertrophic cardiomyopathy >50 years of age.

Various treatment modalities have been introduced to reduce the subaortic pressure gradient in patients with obstructive hypertrophic cardiomyopathy, including pacemaker insertion. Complete ventricular capture during pacing is essential and requires optimization of the atrioventricular interval (AVI). In this study, a protocol using echocardiographic examination assessing the changes in the left ventricular outflow tract (LVOT) gradient in different AVIs, pacing rates, and pacing modes was used for optimal pacemaker programming.

Frequency of spontaneous and inducible atrioventricular nodal reentry tachycardia in patients with idiopathic outflow tract ventricular arrhythmias.

Objectives: We sought to assess the frequency of spontaneous or inducible atrioventricular nodal reentry tachycardia (AVNRT) in patients referred for radiofrequency ablation (RFA) of idiopathic outflow tract ventricular arrhythmias.

Background: In patients with no obvious heart disease, AVNRT and outflow tract ventricular tachycardia (VT) are the most frequently encountered supraventricular and ventricular tachycardias, respectively. An increased coexistence of the two arrhythmias has been recently suggested.

Idiopathic left ventricular tachycardia with a right bundle branch block morphology and left axis deviation ("Belhassen type"): results of radiofrequency ablation in 18 patients.

Background: Idiopathic left ventricular tachycardia with a right bundle branch block configuration and left axis deviation, first described by Belhassen et al., is a rare electrocardiographic-electrophysiologic entity. Radiofrequency catheter ablation has been proposed as a good therapeutic option, but the best criteria for determining the optimal site of ablation are still under debate.

The anti-inflammatory effects of 1,25-dihydroxyvitamin D3 on Th2 cells in vivo are due in part to the control of integrin-mediated T lymphocyte homing.

The fat soluble vitamin D3 metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)(2)D(3)], and its nuclear receptor play an important role in regulating immune responses. While 1,25(OH)(2)D(3 )is known to inhibit transcription of cytokine genes that are required for Th1 differentiation or are products of differentiated Th1 cells, its role in regulating differentiation of Th2 cells is less clear. In this study, we show that 1,25(OH)(2)D(3) has anti-inflammatory effects in an in vivo Th2-dependent asthma model.

Cutting edge: anti-inflammatory properties of low levels of IFN-gamma.

Activation of naive T and B cells occurs only within the context of organized lymphoid tissue. Thus, the continuous recirculation of mature lymphocytes is crucial for the development of primary immune response to foreign Ags. We have previously shown that low levels of IFN-gamma inhibit homing of B cells to the secondary lymphoid organs.

Preferential Th1 immune response in invariant chain-deficient mice.

MHC class II molecules associate with the invariant chain (Ii) molecule during biosynthesis. Ii facilitates the folding of class II molecules, interferes with their peptide association, and is involved in MHC class II transport. In this study, we have investigated the in vitro and in vivo immune response of Ii-deficient mice (Ii(-/-)).