Provocation and localization of atrial ectopy in patients with atrial septal defects.

Background: Atrial fibrillation (AF) is associated with atrial septal defects (ASDs), but the mechanism of arrhythmia in these patients is poorly understood. We hypothesised that right-sided atrial ectopy may predominate in this cohort. Here, we aimed to localise the origin of spontaneous and provoked atrial ectopy in ASD patients.

Transseptal puncture for left atrial ablation: Risk factors for cardiac tamponade and a proposed causative classification system.

Aims: Cardiac tamponade is a high morbidity complication of transseptal puncture (TSP). We examined the associations of TSP-related cardiac tamponade (TRCT) for all patients undergoing left atrial ablation at our center from 2016 to 2020.

Methods And Results: Patient and procedural variables were extracted retrospectively.

Transvenous lead extraction on uninterrupted anticoagulation: A safe approach?

Introduction: Current guidelines advocate reviewing peri-procedural anticoagulation on individual case basis for transvenous lead extraction (TLE). We investigated the safety of TLE on uninterrupted warfarin with therapeutic INR.

Methods: Retrospective registry of consecutive patients undergoing TLE on uninterrupted warfarin (Warfarin Group) across two centres.

Initial experience of the High-Density Grid catheter in patients undergoing catheter ablation for atrial fibrillation.

Purpose: A significant proportion of patients undergoing catheter ablation for atrial fibrillation (AF) experience arrhythmia recurrence. This is mostly due to pulmonary vein reconnection (PVR). Whether mapping using High-Density Wave (HDW) technology is superior to standard bipolar (SB) configuration at detecting PVR is unknown.

Percutaneous left ventricular endocardial leads: adverse outcomes and a percutaneous extraction case series.

Background: Conventional cardiac resynchronization therapy (CRT) involves the placement of an epicardial left ventricular (LV) lead through the coronary venous tree. However, alternative approaches of delivering CRT have been sought for patients who fail to respond to conventional methods or for those where coronary venous anatomy is unfavourable. Biventricular pacing through an endocardial LV lead has potential advantages; however, the long-term clinical and safety data are not known.

Chronic performance of Riata 1580 and Endotak 0158 ICD leads: A single center 10-year experience.

Background: The long-term performance of the Riata family of leads has recently come under increasing scrutiny. We aimed to determine the long-term performance of the Riata 1580 leads compared with Endotak 0158 leads.

Methods: All patients with Riata 1580 or Endotak 0158 leads implanted from 2003 to 2008 at the Heart Hospital, UCLH were analyzed.

Atrial tachyarrhythmias following percutaneous device closure of secundum atrial septal defects.

Background: Atrial tachyarrhythmias (ATs) are a major source of morbidity in the atrial septal defect (ASD) patient cohort. The optimal timing and approach of anti-arrhythmic intervention is currently unclear. Here, we sought to determine the overall rate of ATs following percutaneous ASD closure and risk factors that may predict this.

Ultra-High-Density Activation Mapping to Aid Isthmus Identification of Atrial Tachycardias in Congenital Heart Disease.

Objectives: A new electroanatomic mapping system (Rhythmia, Boston Scientific, Marlborough, Massachusetts) using a 64-electrode mapping basket is now available; we systematically assessed its use in complex congenital heart disease (CHD).

Background: The incidence of atrial arrhythmias post-surgery for CHD is high. Catheter ablation has emerged as an effective treatment, but is hampered by limitations in the mapping system's ability to accurately define the tachycardia circuit.

Inter-Rater Reliability and Downstream Financial Implications of Electrocardiography Screening in Young Athletes.

Background: Preparticipation screening for cardiovascular disease in young athletes with electrocardiography is endorsed by the European Society of Cardiology and several major sporting organizations. One of the concerns of the ECG as a screening test in young athletes relates to the potential for variation in interpretation. We investigated the degree of variation in ECG interpretation in athletes and its financial impact among cardiologists of differing experience.

Radiofrequency ablation of atrial tachyarrhythmias in adults with tetralogy of Fallot - predictors of success and outcome.

Background: Adults with tetralogy of Fallot experience atrial tachyarrhythmias; however, there are a few data on the outcomes of radiofrequency ablation. We examined the characteristics, outcome, and predictors of recurrence of atrial tachyarrhythmias after radiofrequency ablation in tetralogy of Fallot patients. Methods/results Retrospective data were collected from 2004 to 2013.

A systematic review of ICD complications in randomised controlled trials versus registries: is our 'real-world' data an underestimation?

Implantable cardioverter defibrillator (ICD) implantation carries a significant risk of complications, however published estimates appear inconsistent. We aimed to present a contemporary systematic review using meta-analysis methods of ICD complications in randomised controlled trials (RCTs) and compare it to recent data from the largest international ICD registry, the US National Cardiovascular Data Registry (NCDR). PubMed was searched for any RCTs involving ICD implantation published 1999-2013; 18 were identified for analysis including 6433 patients, mean follow-up 3 months-5.

Catheter ablation of atrial fibrillation-patient satisfaction from a single-center UK experience.

Background: Patient satisfaction is an indicator of quality of care and a key factor for patients' healthcare choices. Although atrial fibrillation (AF) ablation is now common, there are no published data on patient satisfaction during this procedure.

Methods: Anonymous patient satisfaction questionnaires were distributed to consecutive AF ablation patients over 6 months at a single center.

Improved electrogram attenuation during ablation of paroxysmal atrial fibrillation with the Hansen robotic system.

Background: Robotic catheter ablation aims to improve outcomes after ablation of atrial fibrillation (AF) through improved lesion quality. This study examined electrogram attenuation as a measure of efficacy in response to robotic (ROB) and manual (MAN) ablation.

Methods: Patients with paroxysmal AF undergoing ablation as part of an ongoing randomized controlled trial were studied (Clinical Trials Registration NCT01037296).

Increasing circulating IGFBP1 levels improves insulin sensitivity, promotes nitric oxide production, lowers blood pressure, and protects against atherosclerosis.

Low concentrations of insulin-like growth factor (IGF) binding protein-1 (IGFBP1) are associated with insulin resistance, diabetes, and cardiovascular disease. We investigated whether increasing IGFBP1 levels can prevent the development of these disorders. Metabolic and vascular phenotype were examined in response to human IGFBP1 overexpression in mice with diet-induced obesity, mice heterozygous for deletion of insulin receptors (IR(+/-)), and ApoE(-/-) mice.

An unusual presentation of primary renal hypokalemia-hypomagnesemia (Gitelman's syndrome).

Gitelman's syndrome, or congenital hypokalemic hypomagnesemic hypocalciuria with metabolic alkalosis, is widely described as a benign or milder variant of Bartter's syndrome and most commonly presents with transient periods of weakness and fatigue, presyncope, vertigo, ataxia, and blurred vision, though aborted sudden cardiac death has also been rarely reported. Despite this there are limited data in the literature regarding the formal cardiac evaluation of patients with Gitelman's syndrome. We present the case of a gentleman with Gitelman's syndrome who initially presented to his primary physician with symptoms suggestive of an upper respiratory tract infection and subsequently survived a ventricular fibrillation (VF) cardiac arrest in the community.

Vascular insulin-like growth factor-I resistance and diet-induced obesity.

Obesity and type 2 diabetes mellitus are characterized by insulin resistance, reduced bioavailability of the antiatherosclerotic signaling molecule nitric oxide (NO), and accelerated atherosclerosis. IGF-I, the principal growth-stimulating peptide, which shares many of the effects of insulin, may, like insulin, also be involved in metabolic and vascular homeostasis. We examined the effects of IGF-I on NO bioavailability and the effect of obesity/type 2 diabetes mellitus on IGF-I actions at a whole-body level and in the vasculature.

Effect of endothelium-specific insulin resistance on endothelial function in vivo.

Objective: Insulin resistance is an independent risk factor for the development of cardiovascular atherosclerosis. A key step in the development of atherosclerosis is endothelial dysfunction, manifest by a reduction in bioactivity of nitric oxide (NO). Insulin resistance is associated with endothelial dysfunction; however, the mechanistic relationship between these abnormalities and the role of impaired endothelial insulin signaling versus global insulin resistance remains unclear.

Catheter ablation of premature ventricular contraction-induced cardiomyopathy.

Background: A 44-year-old female presented with a long history of chest pain, palpitations and increasing dyspnea. Electrocardiography and 24 h Holter monitoring revealed multiple premature ventricular complexes (PVCs), and echocardiography demonstrated significant left ventricular dilatation and systolic impairment. After further investigation it was concluded that this cardiomyopathy was secondary to the observed multiple PVCs and that these represented a potential target for treatment.

The role of IGF-I and its binding proteins in the development of type 2 diabetes and cardiovascular disease.

Patients with insulin resistance and type 2 diabetes have an excessive risk of cardiovascular disease (CVD); this increased risk is not fully explained by traditional risk factors such as hypertension and dyslipidaemias. There is now compelling evidence to suggest that abnormalities of insulin-like growth factor-I (IGF-I) and one of its binding proteins, insulin-like growth factor-binding protein-1 (IGFBP-1), occur in insulin-resistant states and may be significant factors in the pathophysiology of CVD. We reviewed articles and relevant bibliographies following a systematic search of MEDLINE for English language articles between 1966 and the present, using an initial search strategy combining the MeSH terms: IGF, diabetes and CVD.

Insulin and endothelial function: physiological environment defines effect on atherosclerotic risk.

A number of population studies have suggested that hyperinsulinaemia is an independent risk factor for the development of cardiovascular atherosclerosis. Furthermore, there is an emerging body of evidence supporting a role for insulin as both a vasoregulatory and glucoregulatory peptide. Principal amongst insulin's putative vascular effects is to stimulate release of the anti-atherosclerotic signalling molecule nitric oxide (NO) from endothelial cells.

Accelerated endothelial dysfunction in mild prediabetic insulin resistance: the early role of reactive oxygen species.

Insulin resistance is well established as an independent risk factor for the development of type 2 diabetes and cardiovascular atherosclerosis. Most studies have examined atherogenesis in models of severe insulin resistance or diabetes. However, by the time of diagnosis, individuals with type 2 diabetes already demonstrate a significant atheroma burden.

IGF-binding protein-2 protects against the development of obesity and insulin resistance.

Proliferation of adipocyte precursors and their differentiation into mature adipocytes contributes to the development of obesity in mammals. IGF-I is a potent mitogen and important stimulus for adipocyte differentiation. The biological actions of IGFs are closely regulated by a family of IGF-binding proteins (IGFBPs), which exert predominantly inhibitory effects.