Transcatheter Mitral Valve Repair via MitraClip in Patients Aged <65 Years: Multicentre 2-year Outcomes.

Background: Transcatheter mitral valve repair (TMVR) using the MitraClip has become a well-established interventional therapy and is usually performed in elderly patients. The objective of this study was to assess 2-year clinical outcomes of TMVR in patients aged <65 years at three heart centres with severe mitral regurgitation (MR) and no surgical options.

Methods: A retrospective study analysed data of 36 patients aged <65 years treated with TMVR .

Impact of balloon predilatation in patients with reduced versus preserved ejection fraction during transcatheter aortic valve implantation.

Background: Although there is a trend toward direct transcatheter aortic valve implantation (TAVI), still balloon predilatation is necessary in some cases, especially in patients with severe calcification. However, predilatation including rapid ventricular pacing may have adverse outcomes, especially in patients with reduced ejection factor (EF).

Objective: To evaluate the impact of predilatation on in-hospital outcomes in patients with reduced versus preserved EF underwent TAVI.

Outcomes of Redo Transcatheter Aortic Valve Replacement According to the Initial and Subsequent Valve Type.

Background: As transcatheter aortic valve (TAV) replacement is increasingly used in patients with longer life expectancy, a sizable proportion will require redo TAV replacement (TAVR). The unique configuration of balloon-expandable TAV (bTAV) vs a self-expanding TAV (sTAV) potentially affects TAV-in-TAV outcome.

Objectives: The purpose of this study was to better inform prosthesis selection, TAV-in-TAV outcomes were assessed according to the type of initial and subsequent TAV.

Transcatheter aortic valve-in-valve implantation to treat aortic para-valvular regurgitation after TAVI.

Background: Para-valvular regurgitation (PVR) after transcatheter aortic valve (TAV) implantation is associated with increased mortality. Redo-TAVI may be applied to treat PVR, yet with unknown efficacy. We thought to assess redo-TAVI efficacy in reducing PVR using the Redo-TAVI registry (45 centers; 600 TAV-in-TAV cases).

Transcatheter Mitral Valve Replacement After Surgical Repair or Replacement: Comprehensive Midterm Evaluation of Valve-in-Valve and Valve-in-Ring Implantation From the VIVID Registry.

Background: Mitral valve-in-valve (ViV) and valve-in-ring (ViR) are alternatives to surgical reoperation in patients with recurrent mitral valve failure after previous surgical valve repair or replacement. Our aim was to perform a large-scale analysis examining midterm outcomes after mitral ViV and ViR.

Methods: Patients undergoing mitral ViV and ViR were enrolled in the Valve-in-Valve International Data Registry.

A safe and simple technique for crossing stenotic aortic valves.

Objectives: To describe and to validate a new technique for crossing stenotic aortic valves (AV).

Background: Current techniques for crossing the AV may be time-consuming and hazardous.

Methods: One hundred consecutive patients with severe aortic stenosis treated by transfemoral TAVI were prospectively selected to have an initial attempt of 5 min to cross the AV with a novel pigtail/J-wire technique before switching to the conventional Amplatz/straight wire approach.

Repeat Transcatheter Aortic Valve Replacement for Transcatheter Prosthesis Dysfunction.

Background: Transcatheter aortic valve replacement (TAVR) use is increasing in patients with longer life expectancy, yet robust data on the durability of transcatheter heart valves (THVs) are limited. Redo-TAVR may play a key strategy in treating patients in whom THVs fail.

Objectives: The authors sought to examine outcomes following redo-TAVR.

Current Generation Balloon-Expandable Transcatheter Valve Positioning Strategies During Aortic Valve-in-Valve Procedures and Clinical Outcomes.

Objectives: This study sought to evaluate SAPIEN 3 (S3) (Edwards Lifesciences, Irvine, California) positioning using different strategies.

Background: Aortic valve-in-valve (ViV) is associated with high risk of elevated gradients.

Methods: S3 aortic ViV procedures in stented bioprostheses were studied.

Transcatheter aortic valve-in-valve implantation in degenerative rapid deployment bioprostheses.

Aims: The aim of this study was to evaluate transcatheter aortic valve-in-valve (ViV) implantation performance in rapid deployment (ViVr) vs. conventional (ViVc) surgical heart valves.

Methods And Results: A multicentre registry was developed as part of the VIVID international registry.

Transient repolarization instability following the initiation of cardiac resynchronization therapy.

Aims: Cardiac resynchronization therapy (CRT) may cause changes in ventricular repolarization (VR), particularly in the initial phase of treatment. This study investigated the effect of CRT cessation and re-initiation on parameters of VR duration and heterogeneity at different paced heart rates.

Methods: Cardiac resynchronization therapy was inactivated for 2 weeks in 16 treatment responders to CRT.

Green tea flavonoid epigallocatechin-3-gallate (EGCG) inhibits cardiac hERG potassium channels.

The catechin EGCG is the main flavonoid compound of green tea and has received enormous pharmacological attention because of its putative beneficial health effects. This study investigated for the first time the effect of EGCG on hERG channels, the main pharmacological target of drugs that cause acquired long QT syndrome. Cloned hERG channels were expressed in Xenopus oocytes and in HEK293 cells.

Optimizing implantable cardioverter-defibrillator treatment of rapid ventricular tachycardia: antitachycardia pacing therapy during charging.

Background: Previous studies in implantable cardioverter-defibrillator (ICD) patients demonstrated the efficacy and safety of antitachycardia pacing (ATP) for rapid ventricular tachycardias (VT). To prevent shock delay in case of ATP failure, a new feature (ATP during charging) was developed to deliver ATP for rapid VT while charging for shock.

Objective: The purpose of this study was to determine the efficacy and safety of this new feature.

Indications for predismissal testing with arrhythmia-induction in patients receiving an implantable cardioverter defibrillator.

Unlabelled: Arrhythmia induction during implantation of cardioverter defibrillators (ICD) is a standard procedure. However, controversy exists regarding the need for routine arrhythmia induction before discharge from hospital (pre-hospital discharge (PHD) test). In order to reduce the number of tests we identified risk factors that predict relevant ICD malfunction.

Cardiac-specific activation of Cre expression at late fetal development.

In a first step towards dissecting molecular mechanisms that contribute to the development of cardiac diseases, we have generated transgenic mice that express a Cre-GFP fusion protein under the transcriptional control of a 4.3kb murine cardiac Troponin I gene (cTnI) promoter. Cre-GFP expression, similar in three transgenic lines, is described in one line.

Prevention of inappropriate shocks in ICD recipients: a review of 10,000 tachycardia episodes.

Background: The efficacy of dual-chamber ICD arrhythmia classification algorithms is crucial to prevent inappropriate shocks. We report our experience from a meta-analysis of five prospective clinical studies with inclusion phases ranging between 1997 and 2003.

Methods: Dual-chamber ICD using standard dual-chamber arrhythmia classification algorithms were implanted in 802 patients (mean age = 64 +/- 11 years, 88% men) in 74 medical centers.

Role of KATP channels in repetitive induction of ventricular fibrillation.

Aim: Patients with sustained ventricular tachyarrhythmias are at high risk for sudden cardiac death. The mechanisms leading to multiple temporally related episodes of ventricular fibrillation (VF) are not yet fully elucidated, and treatment options are limited. We investigated whether K(ATP)-channels could be involved in triggering VF.

Brief antecedent anoxia preserves mitochondrial function after sustained undersupply: a subcellular correlate to ischemic preconditioning?

Background: There is increasing evidence that mitochondria - owning a high degree of autonomy within the cell - might represent the target organelles of the myocardial protection afforded by ischemic preconditioning. It was the aim of the study to investigate a possible subcellular correlate to ischemic preconditioning at the mitochondrial level. In addition, we tested whether this protection depends on mitochondrial ATP-dependent potassium channels (K (ATP)) and an might involve an attenuation of mitochondrial ATP hydrolysis during sustained anoxia.

Regulation of cardiac inwardly rectifying potassium current IK1 and Kir2.x channels by endothelin-1.

To elucidate the ionic mechanism of endothelin-1 (ET-1)-induced focal ventricular tachyarrhythmias, the regulation of I(K1) and its main molecular correlates, Kir2.1, Kir2.2 and Kir2.

Myocardial energy metabolism in ischemic preconditioning and cardioplegia: a metabolic control analysis.

For both, cardioplegia (CP) and ischemic preconditioning (IP), increased ischemic tolerance with reduction in infarct size is well documented. These cardioprotective effects are related to a limitation of high energy phosphate (HEP) depletion. As CP and IP have to be assumed to act by different mechanisms, their effects on myocardial HEP metabolism cannot be assumed to be identical.

Acquired arteriovenous fistula and chronic occlusion of the left anterior descending coronary artery in a patient with previous ablation of a left-sided accessory pathway.

Endocardial catheter ablation of accessory pathways is now considered as therapy of first choice in symptomatic patients. Success rates depend on the location of the accessory pathway itself and the operators experience in catheter ablation procedures. In patients with a left-sided pathway the retrograde transaortic catheter approach is used routinely in most centers.

Inhibition of cardiac HERG channels by grapefruit flavonoid naringenin: implications for the influence of dietary compounds on cardiac repolarisation.

Flavonoids are naturally occurring food ingredients that have been associated with reduced cardiovascular mortality in epidemiological studies. In a previous study, we demonstrated for the first time that flavonoids are inhibitors of cardiac human ether-à-go-go-related gene (HERG) channels. Furthermore, we observed that grapefruit juice induced mild QTc prolongation in healthy subjects.

Regional differences in the dynamics of refractoriness in intact and hypertrophied in situ canine hearts.

Objectives: Functional re-entry is thought to represent the predominant mechanism underlying ventricular arrhythmias. Functional conduction block may be caused by regional dispersion of refractoriness (ERP). Dispersion of ERP may not be evident at baseline, but may occur with sudden changes in heart rate, as ventricular arrhythmias are commonly induced by short-long-short cycles.