Effects of Acute Autonomic Modulation on Atrial Conduction Delay and Local Electrograms Duration in Paroxysmal Atrial Fibrillation

Slowed atrial conduction may contribute to reentry circuits and vulnerability for atrial fibrillation (AF). The autonomic nervous system (ANS) has modulating effects on electrophysiological properties. However, complex interactions of the ANS with the arrhythmogenic substrate make it difficult to understand the mechanisms underlying induction and maintenance of AF. AIM: To determine the effect of acute ANS modulation in atrial activation times in patients (P) with paroxysmal AF (PAF). METHODS AND RESULTS: 16P (9 men; 59±14years) with PAF, who underwent electrophysiological study before AF ablation, and 15P (7 men; 58±11years) with atrioventricular nodal reentry tachycardia, without documentation or induction of AF (control group). Each group included 7P with arterial hypertension but without underlying structural heart disease. The study was performed while off drugs. Multipolar catheters were placed at the high right atrium (HRA), right atrial appendage (RAA), coronary sinus (CS) and His bundle area (His). At baseline and with HRA pacing (600ms, shortest propagated S2) we measured: i) intra-atrial conduction time (IACT, between RAA and atrial deflection in the distal His), ii) inter-atrial conduction time (interACT, between RAA and distal CS), iii) left atrial activation time (LAAT, between atrial deflection in the distal His and distal CS), iv) bipolar electrogram duration at four atrial sites (RAA, His, proximal and distal CS). In the PAF group, measurements were also determined during handgrip and carotid sinus massage (CSM), and after pharmacological blockade of the ANS (ANSB). AF was induced by HRA programmed stimulation in 56% (self-limited - 6; sustained - 3), 68.8% (self-limited - 6; sustained - 5), and 50% (self-limited - 5; sustained - 3) of the P, in basal, during ANS maneuvers, and after ANSB, respectively (p=NS). IACT, interACT and LAAT significantly lengthened during HRA pacing in both groups (600ms, S2). P with PAF have longer IACT (p<0.05), a higher increase in both IACT, interACT (p<0.01) and electrograms duration (p<0.05) with S2, and more fragmented activity, compared with the control group. Atrial conduction times and electrograms duration were not significantly changed during ANS stimulation. Nevertheless, ANS maneuvers increased heterogeneity of the local electrograms duration. Also, P with sustained AF showed longer interACT and LAAT during CSM. CONCLUSION: Atrial conduction times, electrograms duration and fractionated activity are increased in PAF, suggesting a role for conduction delays in the arrhythmogenic substrate. Acute vagal stimulation is associated with prolonged interACT and LAAT in P with inducible sustained AF and ANS modulation may influence the heterogeneity of atrial electrograms duration.

One Anastomosis Gastric Bypass versus Roux en Y Gastric Bypass as Salvage Technique after Failed Gastric Band: a Retrospective Analysis of 80 Cases

The classical “Roux en Y Gastric Bypass” (RYGBP) is still the standard technique between all the ones being used nowadays. The “One anastomosis gastric bypass” (OAGBP), is an evolution of the “Minigastic bypass” described by Robert Rutledge in 2001, is a well known and progressively frequent but still controversial technique. In our group, after an experience of 10 years using the RYGBP as a salvage surgery after failed gastric banding, in 132 cases, we decided to adopt the OAGBP as our preferential bariatric technique also in this situation. The theoretical main reasons for that shift are related to the increased safety, maximized weight loss, long term weight loss maintenance and reversibility of the operation. Method: Retrospectively we evaluated data of the surgical management of revisional cases for conversion, after failed or complicated gastric bands to gastric bypass. We selected the last 40 cases of each technique since May 2010. Results: All cases were performed by laparoscopy without any conversion. In both groups the conversion has been performed in one single step (17 cases, 42,5%). Data showed lower morbidity with OAGBP (2,5% against 7,5%) and better weight loss in theOAGBP cohort after a median follow up of 16months (67%against 55%) in patients revised after gastric band failure or complications. None had statistic significance (p>0,1) by the chi-square contingency table analysis.Conclusion: It seems to there is a difference in favour of OAGBP for conversion of complicated gastric bands. In this study we didn’t found statistic significance probably because of the short numbers. Prospective and more powerful studies are necessary to evaluate the benefit of the studied procedure.

The Role of Sensory Modulation Deficits and Behavioral Symptoms in a Diagnosis for Early Childhood

To contribute to the validation of the sensory and behavioral criteria for Regulation Disorders of Sensory Processing (RDSP) (DC:0-3R, 2005), this study examined a sample of toddlers in a clinical setting to analyze: (1) the severity of sensory modulation deficits and the behavioral symptoms of RDSP; (2) the associations between sensory and behavioral symptoms; and (3) the specific role of sensory modulation deficits in an RDSP diagnosis. Based on clinical observations, 78 toddlers were classified into two groups: toddlers with RDSP (N = 18) and those with‘‘other diagnoses in Axis I/II of the DC:0-3R’’ (OD3R; N = 60). The parents completed the Infant Toddler Sensory Profile and the Achenbach Checklist. The results revealed that the RDSP group had more severe sensory modulation deficits and specific behavioral symptoms; stronger, although not significant, associations between most sensory and behavioral symptoms; and a significant sensory modulation deficit effect. These findings support the validity of RDSP.