A simple semi-empirical theory is developed for the ionic strength dependence of the flexible polymer-induced condensation of semiflexible polyelectrolytes such as DNA and F-actin filaments. Critical concentrations of flexible polymer needed for condensation are calculated by comparing the free energies of inserting the semiflexible polyelectrolytes in a solution of flexible polymers, respectiv...

A new technique for ablation of atrioventricular nodal reentrant tachycardia, using catheter-directed continuous wave Nd-YAG laser light, 1064 nm, via a novel pin-electrode laser catheter, was applied in 10 patients aged 15-63 years (mean 43 years). A total of 22 laser pulses, 1-5 per patient, at 20 or 30 W, of 10-45 s (mean 27 s) were aimed at the postero-inferior aspect of the tricuspid annul...

Slow Pathway Ablation. Introduction: The relationship between temperature at the electrode-tissue interface and the loss of AV and ventriculoatrial (VA) conduction is not established, and the optimal target temperature for the slow pathway approach to radiofrequency ablation of AV nodal reentrant tachycardia (AVNRT) is unknown. Therefore, the purpose of this study was to compare target temperat...

S low pathway ablation provides curative treatment for patients with atrioventricular nodal re-entrant tachycardia (AVNRT). The major concern remains the induction of complete atrioventricular (AV) block. To minimise the risk, many centres apply a stepwise approach, targeting initially inferoposterior sites of the septal annulus of the tricuspid valve. If the first ablation attempts are unsucce...

BACKGROUND Catheter ablation of the slow conducting pathway (SP) is treatment of choice for atrioventricular nodal reentrant tachycardia (AVNRT). Although there are abundant data on AVNRT ablation in adult patients, little is known about the long-term results ≥3 years after AVNRT ablation in pediatric patients. METHODS AND RESULTS Follow-up data from 241 patients aged ≤18 years who had underg...

Introduction Unroofed coronary sinus is a rare congenital anomaly that may alter the complex anatomy of the atrioventricular (AV) node. Arrhythmia circuits occurring among these patients may not be located in the usual position, especially those circuits involving the AV node. We report a case of the coexistence of this uncommon coronary sinus (CS) anomaly and the atypical form of atrioventricu...

Atrioventricular nodal reentrant tachycardia is the most common mechanism of paroxysmal supraventricular tachycardia in adults and is relatively uncommon in children. While the precise anatomy of the reentry circuit underlying AVNRT and relative role of the atrioventricular node and extranodal atrial inputs remain controversial, the electrophysiologic mechanism of the arrhythmia involving the c...

Eight cases of ventricular parasystole are reported. In all these cases, regardless of whether parasystole seems intermittent or "continuous," the presence of second degree entrance block of the Mobitz type I was suggested. Parasystole alternated with concealed extrasystolic bigeminy showing occasional reentrant extrasystoles. Such intermittent parasystole appears to originate in the reentrant ...

Two patients with supraventricular parasystole (one atrioventricular and one auricular) are reported. In both patients, reentrant extrasystoles appeared to occur as the result of Mobitz type I second-degree entrance block. We believe that when a sinus impulse fell soon after the absolute refractory period of the pathway containing the parasytolic focus, it reached and discharged the focus after...

BACKGROUND AND OBJECTIVES Some studies have demonstrated that the use of propofol is occasionally associated with bradyarrhythmias or reversion of arrhythmias to sinus rhythm. This property of propofol suggests interference with the Cardiac Conduction System (CCS). CONTENTS A review of the main contemporary articles on the use of propofol in the presence of cardiac arrhythmias was undertaken....