Dynamics of Focal Fibrillation Waves during Persistent Atrial Fibrillation.

The incidence and appearance of focal fibrillation waves on the right and left atrial epicardial surface were visualized during 10 seconds of persistent atrial fibrillation in a 71-year-old woman with valvular heart disease. The frequent, nonrepetitive, widespread, and capricious distribution of focal waves suggests that transmural conduction of fibrillation waves is most likely the mechanism underlying focal fibrillation waves.

Complex MHC Class I Gene Transcription Profiles and Their Functional Impact in Orangutans.

MHC haplotypes of humans and the African great ape species have one copy of the MHC-A, -B, and -C genes. In contrast, MHC haplotypes of orangutans, the Asian great ape species, exhibit variation in the number of gene copies. An in-depth analysis of the MHC class I gene repertoire in the two orangutan species, Pongo abelii and Pongo pygmaeus, is presented in this article.

Detailed characterization of familial idiopathic ventricular fibrillation linked to the DPP6 locus.

Background: Familial idiopathic ventricular fibrillation (IVF) is a severe disease entity and is notoriously difficult to manage because there are no clinical risk indicators for premature cardiac arrest. Previously, we identified a link between familial IVF and a risk haplotype on chromosome 7q36 (involving the arrhythmia gene DPP6).

Objective: The purpose of this study was to expand our knowledge of familial IVF and to discuss its (extended) clinical characteristics.

HALT & REVERSE: Hsf1 activators lower cardiomyocyt damage; towards a novel approach to REVERSE atrial fibrillation.

Background: Atrial fibrillation is a progressive arrhythmia, the exact mechanism underlying the progressive nature of recurrent AF episodes is still unknown. Recently, it was found that key players of the protein quality control system of the cardiomyocyte, i.e.

A novel intra-operative, high-resolution atrial mapping approach.

Purpose: A new technique is demonstrated for extensive high-resolution intra-operative atrial mapping that will facilitate the localization of atrial fibrillation (AF) sources and identification of the substrate perpetuating AF.

Methods: Prior to the start of extra-corporal circulation, a 8 × 24-electrode array (2-mm inter-electrode distance) is placed subsequently on all the right and left epicardial atrial sites, including Bachmann's bundle, for recording of unipolar electrograms during sinus rhythm and (induced) AF. AF is induced by high-frequency pacing at the right atrial free wall.

Feasibility and Accuracy of Cardiac Magnetic Resonance Imaging-Based Whole-Heart Inverse Potential Mapping of Sinus Rhythm and Idiopathic Ventricular Foci.

Background: Inverse potential mapping (IPM) noninvasively reconstructs cardiac surface potentials using body surface potentials. This requires a volume conductor model (VCM), usually constructed from computed tomography; however, computed tomography exposes the patient to harmful radiation and lacks information about tissue structure. Magnetic resonance imaging (MRI) is not associated with this limitation and might have advantages for mapping purposes.

Non-invasive focus localization, right ventricular epicardial potential mapping in patients with an MRI-conditional pacemaker system - a pilot study.

Background: With the advent of magnetic resonance imaging (MRI) conditional pacemaker systems, the possibility of performing MRI in pacemaker patients has been introduced. Besides for the detailed evaluation of atrial and ventricular volumes and function, MRI can be used in combination with body surface potential mapping (BSPM) in a non-invasive inverse potential mapping (IPM) strategy. In non-invasive IPM, epicardial potentials are reconstructed from recorded body surface potentials (BSP).

Diagnosis and Therapy of Atrial Fibrillation: The Past, The Present and The Future.

Atrial fibrillation (AF) is the most common age-related cardiac arrhythmia. It is a progressive disease, which makes treatment difficult. The progression of AF is caused by the accumulation of damage in cardiomyocytes which makes the atria more vulnerable for AF.

Co-evolution of the MHC class I and KIR gene families in rhesus macaques: ancestry and plasticity.

Researchers dealing with the human leukocyte antigen (HLA) class I and killer immunoglobulin receptor (KIR) multi-gene families in humans are often wary of the complex and seemingly different situation that is encountered regarding these gene families in Old World monkeys. For the sake of comparison, the well-defined and thoroughly studied situation in humans has been taken as a reference. In macaques, both the major histocompatibility complex class I and KIR gene families are plastic entities that have experienced various rounds of expansion, contraction, and subsequent recombination processes.

Time Course of Atrial Fibrillation in Patients With Congenital Heart Defects.

Background: The incidence of atrial fibrillation (AF) is rising in the aging patients with congenital heart defects (CHD). However, studies reporting on AF in patients with CHD are scarce. The aim of this multicenter study was to examine in a large cohort of patients with a variety of CHD: (1) the age of onset and initial treatment of AF, coexistence of atrial tachyarrhythmia and (2) progression of paroxysmal to (long-standing) persistent/permanent AF during long-term follow-up.

A priori model independent inverse potential mapping: the impact of electrode positioning.

Introduction: In inverse potential mapping, local epicardial potentials are computed from recorded body surface potentials (BSP). When BSP are recorded with only a limited number of electrodes, in general biophysical a priori models are applied to facilitate the inverse computation. This study investigated the possibility of deriving epicardial potential information using only 62 torso electrodes in the absence of an a priori model.

Clinical Presentation, Long-Term Follow-Up, and Outcomes of 1001 Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy Patients and Family Members.

Background: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a progressive cardiomyopathy. We aimed to define long-term outcome in a transatlantic cohort of 1001 individuals.

Methods And Results: Clinical and genetic characteristics and follow-up data of ARVD/C index-patients (n=439, fulfilling of 2010 criteria in all) and family members (n=562) were assessed.

Bradyarrhythmias: first presentation of arrhythmogenic right ventricular cardiomyopathy?

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disorder characterized by progressive replacement of myocardial cells by fibro-fatty tissue giving rise to ventricular tachyarrhythmias. In this case report, we describe a pediatric patient with sinoatrial arrests and second degree atrioventricular conduction block several years before ARVC became apparent. These findings suggest that bradyarrhythmias can also be the first expression of ARVC.

Impact of genotype on clinical course in arrhythmogenic right ventricular dysplasia/cardiomyopathy-associated mutation carriers.

Aims: We sought to determine the influence of genotype on clinical course and arrhythmic outcome among arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C)-associated mutation carriers.

Methods And Results: Pathogenic mutations in desmosomal and non-desmosomal genes were identified in 577 patients (241 families) from USA and Dutch ARVD/C cohorts. Patients with sudden cardiac death (SCD)/ventricular fibrillation (VF) at presentation (n = 36) were younger (median 23 vs.

Management of atrial fibrillation in patients with congenital heart defects.

Due to improved surgical technologies and post-operative care, long-term survival has improved in patients with congenital heart disease. Atrial fibrillation (AF) is increasingly observed in this aging population and is associated with morbidity and mortality; however, reports about the pathophysiology and the outcome of different treatment modalities of AF are still scarce in patients with congenital heart disease. In this review, the authors describe the epidemiology, pathophysiology and outcome of the different therapies of AF in this specific patient population.

Right versus left atrial pacing in patients with sick sinus syndrome and paroxysmal atrial fibrillation (Riverleft study): study protocol for randomized controlled trial.

Background: The incidence of sick sinus syndrome will increase due to population ageing. Consequently, this will result in an increase in the number of pacemaker implantations. The atrial lead is usually implanted in the right atrial appendage, but this position may be ineffective for prevention of atrial fibrillation.

Impact of adverse left ventricular remodeling on sudden cardiac death in patients with hypertrophic cardiomyopathy.

Background: Adverse left ventricular (LV) remodeling predicts heart failure symptoms and overt LV dysfunction in patients with hypertrophic cardiomyopathy (HCM), but its influence on the occurrence of sudden cardiac death (SCD) is unknown. The aim of this study was to investigate the effect of adverse LV remodeling on SCD risk in patients with HCM.

Hypothesis: Adverse LV remodeling increases SCD in HCM patients.

Computing volume potentials for noninvasive imaging of cardiac excitation.

Background: In noninvasive imaging of cardiac excitation, the use of body surface potentials (BSP) rather than body volume potentials (BVP) has been favored due to enhanced computational efficiency and reduced modeling effort. Nowadays, increased computational power and the availability of open source software enable the calculation of BVP for clinical purposes. In order to illustrate the possible advantages of this approach, the explanatory power of BVP is investigated using a rectangular tank filled with an electrolytic conductor and a patient specific three dimensional model.

Nonhuman genetics. Strong male bias drives germline mutation in chimpanzees.

Germline mutation determines rates of molecular evolution, genetic diversity, and fitness load. In humans, the average point mutation rate is 1.2 × 10(-8) per base pair per generation, with every additional year of father's age contributing two mutations across the genome and males contributing three to four times as many mutations as females.