OBJECTIVE Attempts to cardiovert tachycardia by rapid point pacing can sometimes result in transient or stable increase of the heart rate (acceleration), changed ECG morphology, and/or fibrillation. The goal of this study was to investigate the effect of rapid pacing on the dynamics of functional reentry in monolayer cultures of cardiac cells. METHODS Fully confluent, uniformly anisotropic mo...

BACKGROUND Heart failure is operationally defined as the inability of the heart to maintain blood flow to meet the needs of the body and it is the final common pathway of various cardiac pathologies. Electrophysiological remodeling, intercellular uncoupling and a pro-fibrotic response have been identified as major arrhythmogenic factors in heart failure. OBJECTIVE In this study we investigate...

Phase-2 reentry is a basic mechanism for the transition to VT and VF in the heart. It is thought to underly many causes of idiopathic ventricular arrhythmias as, for instance, those occurring in Brugada syndrome. Reentry is usually linked to heterogeneity in tissue repolarization. We study some circumstances under which a region of depolarized tissue can reexcite adjacent regions that exhibit s...

Of the many direct numerical methods, the pseudospectral method serves as an effective tool to solve the reentry trajectory optimization for hypersonic vehicles. However, the traditional pseudospectral method is time-consuming due to large number of discretization points. For the purpose of autonomous and adaptive reentry guidance, the research herein presents a multistage trajectory control st...

BACKGROUND The effect of effective refractory period (ERP) shortening on the vulnerability and characteristics of induced functional reentry in the ventricle remain poorly defined. We hypothesized that ERP shortening increases ventricular vulnerability to reentry and accelerates its rate, as is the case in the atrium. METHODS AND RESULTS The epicardial surfaces of 19 isolated and superfused c...

BACKGROUND The characteristics of transmembrane potential (TMP) at the core of functional reentry in the atrium are not well understood. METHODS AND RESULTS In protocol 1 (11 dogs), isolated perfused canine right atria were mapped from the endocardial surface while simultaneous TMPs were recorded from the epicardial surface. Episodes of reentry (n=64) were induced in the presence of 1 to 5 mi...

This article is based on an ethnographic study involving 58 Roma and Romanian participants who were released from Jilava Prion in Romania between January and July 2015. The methodology involved interviews, observation, questionnaires, and photovoice. The findings seem to suggest that most of the factors associated with desistance and reentry in the literature are relevant to the ex-prisoner's e...

Background Assessment of risk of sudden cardiac death (SCD) due to ventricular tachycardia and fibrillation (VT/VF) remains one of the most challenging areas in management of patients with chronic myocardial infarction. VT substrate consists of reentry circuits near or within a chronic scar. Invasive catheter mapping using electroanatomical system (EAM) is the clinical standard for identificati...

Alternating WEnckebach periodicity is generally believed to reflect bilevel block due to horizontal electrophysiologic dissociation in the conducting tissues. We describe a case of atrial pacing-induced atrioventricular nodal alternating Wenckebach periodicity with concealed reentry in a longitudinally dissociated AV conduction system. Three observations support this unique mechanism: Concealed...

Reentrant waves propagating in a ring or annulus of excitable media are a model of the basic mechanism underlying a major class of irregular cardiac rhythms known as anatomical reentry. Such reentrant waves are terminated by rapid electrical stimulation (pacing) from an implantable device. Because the mechanisms of such termination are poorly understood, we study pacing of anatomical reentry in...