We deal with fractional generalized logistic problems in presence of a signed and unbounded weight. We describe the first eigenpair of the underlying operators and we show a bifurcation result for ...positive solutions, which are proved to be unique. A symmetry result is established under suitable geometric constraints.
Congenital heart disease (CHD) patients represent a challenge for ablation procedures and may require unusual procedural techniques. An example is the absence of femoral venous accesses that makes a ...conventional TSP approach impossible.
We report a series of 6 procedures in which transseptal puncture (TSP) was performed via the jugular vein approach using a radiofrequency (RF) needle visualized on the electroanatomical mapping (EAM) system.
Ablation procedures for either atrial fibrillation and left-sided atrial tachycardia were performed in 3 patients (54-53-29years) with congenital disease and blocked femoral approach (interrupted inferior vena cava with azygos continuation (2 pts), bilaterally blocked femoral venous access due to previous interventions (1 pt)). Using the right jugular(n = 5) and left jugular vein(n = 1) we performed a single TSP using a combination of fluoroscopy and EAM guidance with 3D visualisation of the RF needle tip. The main difficulties encountered and solutions are described. In four procedures, remote magnetic navigation was subsequently used. Left atrial access was gained in all cases without complications. Overall procedural time was 373 321–458 min, with a median fluoroscopy time of 16 8–26 min and median radiation dose of 1442 348–3007 μGym2.
TSP via superior access is feasible in patients with complex congenital cardiac anatomy. Pre-procedural imaging, EAM and the 3D visualisation of the transseptal needle are tools that greatly facilitate the procedural success.
The diagnostic Brugada-electrocardiogram (Br-ECG) is characterized by "coved-type" ST-segment elevation (type 1) in V(1) to V(2)/V(3). The sodium-channel blocker test is clinically used to unmask ...diagnostic Br-ECG in patients with nondiagnostic "saddle-back" Br-ECG (type 2 and type 3).
To assess the prognostic value of the sodium-channel blockers test in individuals with a nondiagnostic Br-ECG.
We studied 153 consecutive patients (128 men; age 41.7 ± 14.0 years) with a type 2/3 Br-ECG who underwent a sodium-channel blocker test with either flecainide (48%) or ajmaline (52%). Nondiagnostic Br-ECGs were identified during the evaluation of cardiac arrest in 5 patients (3%), syncope in 36 (24%), cascade family screening in 48 (31%), and incidental ECG in 64 (42%). A spontaneous type 1 Br-ECG was systematically excluded by serial ECGs (6.1 ± 0.4) and recording of right precordial leads both at standard and second and third intercostal spaces.
The sodium-channel blocker test result was positive in 76 (50%) patients. During a follow-up of 59 ± 33 months, 9 (5.9%) patients experienced events such as syncope (n = 4), appropriate interventions of defibrillator (n = 4), or sudden death (n = 1). A positive sodium-channel blocker test was associated with a significantly higher event rate in symptomatic patients (P = .01) but not in asymptomatic individuals (P = .18). No events occurred among asymptomatic individuals with an incidental nondiagnostic Br-ECG.
In asymptomatic individuals with a nondiagnostic Br-ECG, the incidence of events is low regardless of the sodium-channel blocker test result while in symptomatic patients a positive sodium-channel blocker test result is associated with an adverse arrhythmic outcome and may contribute to risk stratification.
We consider an elliptic problem driven by the square root of the negative Laplacian in the presence of a general logistic function having an indefinite weight. We prove a bifurcation result for the ...associated Dirichlet problem via regularity estimates of independent interest for when the weight belongs only to certain Lebesgue spaces.
Background
The identification of a “low-voltage bridge” to guide ablation of atrioventricular nodal reentry tachycardia (AVNRT) has been described as a safe and effective strategy in children. We ...investigated the presence of a low-voltage bridge in adult patients undergoing AVNRT ablation, to evaluate its anatomical correspondence with the successful ablation site. We also investigated the possible correlations between Koch’s triangle anatomy and patients’ biometric characteristics.
Methods
This observational registry prospectively collected data from 200 patients undergoing AVNRT ablation, guided by 3D electroanatomical mapping system, in 6 electrophysiology centers. Koch’s triangle voltage map was collected; then, the anatomical correspondence between the low-voltage bridge and the successful ablation site was evaluated. Koch’s triangle anatomical dimensions were subsequently drawn from the mapping system and correlated to patients’ gender, age, and weight.
Results
The low-voltage bridge was identified in 159 over 200 procedures (79.5%). When the low-voltage bridge was identified, its anatomical correspondence with the successful ablation site has been proved in 137 over 159 cases (86%), with a reduction of radiofrequency deployment time. No strict correlations were found, on the other side, between Koch’s triangle anatomy and patients’ biometric data.
Conclusions
The identification of the low-voltage bridge has proved to be a helpful strategy to guide AVNRT ablation in a large cohort of adult patients. Targeting the low-voltage bridge during AVNRT ablation helps to reduce RF application time. Koch’s triangle morphological characteristics cannot be predicted on the base of patients’ biometric data.
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