Morphologic Analysis of Left Atrial Anatomy by Magnetic Resonance Angiography in Patients With Atrial Fibrillation: A Large Single Center Experience

LA and PV Anatomy in Patients With AF. Introduction: Although transcatheter atrial fibrillation (AF) ablation requires accurate anatomic knowledge, pulmonary vein (PV) anatomy has not been fully investigated. Aim of this study is to describe left atrium (LA) and PV anatomy by magnetic resonance angiography (MRA) in a large cohort of patients with AF. Methods: MRA was performed in 473 patients preceding transcatheter AF ablation (paroxysmal 60.9%; persistent 39.1%). The Venice Chart classification was used to classify PV branching patterns. Results: About 40% of the patients presented typical PV branching pattern (2 left and 2 right PVs). A representative number of patients presented a common left trunk (19.9% and 11.0% short and long, respectively). A right middle PV was described in 12.5% and 2 right middle PVs in 1.5% patients. The remaining patients presented other complex, previously unclassified patterns: 6.3% presented an accessory PV originating from LA areas not describable as right or “upper” and 8.7% a common left trunk plus right middle PV. Diameters and circumference of each PV, LA, and LA appendage volumes resulted larger in patients presenting persistent compared to paroxysmal AF (P < 0.001). Conclusion: This study highlights that “typical” PV branching pattern is not a common finding. That 25.6% of the patients present at least 1 accessory PV needs to be kept in careful consideration when planning and performing transcatheter AF ablation. In addition, not only LA volume, but also each PV ostia and LA appendage are significantly enlarged in patients with persistent compared to paroxysmal AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1‐7, January 2011)     

Somatosensory mismatch negativity in healthy children

Aim  Event-related potentials (ERPs) obtained when focused attention is kept away from the stimulus (unnoticed stimulation) are possibly linked to automatic mismatch-detection mechanisms, and could be a useful tool to investigate sensory discrimination ability. By considering the high impact of impaired somatosensory integration on many neurological disturbances in children, we aimed to verify whether mismatch-related responses to somatosensory stimulation could be obtained in healthy children.
Method  Eleven healthy participants (age range 6–11y, mean 8y 2mo, SD 1y 7mo; seven males, four females) underwent 'oddball' electrical stimulation of the right hand (80% frequent stimuli delivered to the thumb, 20% deviant stimuli delivered to the fifth finger). Data were compared with those obtained when the frequent stimuli to the thumb were omitted ('standard-omitted' protocol). ERPs were recorded at frontal, central, and parietal scalp locations. Children's overt attention was engaged by a demanding video game.
Results  In the oddball protocol, deviant stimulation elicited a left central negativity at about 160ms latency, followed by a left frontal negative response at about 220ms latency. Standard-omitted traces showed only a left parietal negative response spreading to right parietal regions.
Interpretation  Mismatch-related somatosensory responses can be reliably obtained in children, providing that appropriate technical contrivances are used. In clinical use, the frontal components, which are present only during the oddball protocol, could be a reliable and unequivocal neurophysiological marker of the automatic mismatch-detection mechanism.     

Hypoepiluminescence Microscopy of Pigmented Skin Lesions: New Approach to Improve Recognition of Dermoscopic Structures

BACKGROUND: Hypoepiluminescence microscopy (HELM) is a new dermoscopic approach for analysis of pigmented skin lesions (PSLs) after surgical excision. OBJECTIVES: The objective was to verify whether this method could provide additional morphologic information for diagnostic or didactic purposes compared to conventional epiluminescence microscopy (ELM). PATIENTS AND METHODS: Thirty-one PSLs from 30 patients were consecutively evaluated by ELM and, after excision, by HELM. For HELM examination, the lesion was positioned on a glass slide and illuminated from above with a halogen lamp and from underneath with an LED source. All lesions were subsequently examined histopathologically. RESULTS: In 11 of 31 (35.5%) lesions, a typical pigment network, as assessed by ELM, appeared bidimensional with HELM. In 9 lesions (9/31; 29%) ELM showed a gray-blue area, while HELM allowed us to distinguish 5 lesions (5/9, 55.5%) with gray area predominant showing a lichenoid lymphocytic infiltration and few melanophages from the other 4 lesions (4/9, 44,5%) with heavy dermal accumulation of pigmented melanocytes or melanophages where a blue area was clearly visible at HELM. In 9 other cases (29%), ELM analysis revealed a central homogeneous dark brown/black pigmentation that in 7 cases was seen under HELM examination to consist of globules. CONCLUSIONS: HELM is particularly useful in evaluating heavily PSLs or structures located in the reticular dermis.     

Reasons for persistent and emerging post‐treatment endodontic disease

This article is a critical review of the reasons for persistent and emerging post‐treatment endodontic disease (PTED). While there is a strong consensus that micro‐organisms, mainly bacteria, are practically the only cause of primary apical periodontitis, the reasons for persistent apical periodontitis lesions have been more a matter of debate. The authors of this review focus on the role of micro‐organisms in PTED, and while secondary developments such as cholesterol crystals or foreign material in the periapical area of a tooth with apical periodontitis may contribute to additional irritation and/or an inflammatory reaction, a detailed analysis of the available data suggests that evidence supporting a primary role for such secondary factors without the continued presence of bacteria is lacking. Therefore, even in PTED, elimination of micro‐organisms residing within the tooth structure, root surface, or periapical tissues remains the goal of treatment and the key to long‐term success.     

Anterior Provisional Restorations Used to Determine Form, Function, and Esthetics for Complex Restorative Situations, Using All-Ceramic Restorative Systems

A technique is proposed for the restoration of a large and visible maxillary anterior defect. The importance of proper diagnosis, treatment planning, and communication is emphasized. Irreversible treatment should only be rendered once patient approval has been obtained through objective evaluation with provisional restorations. The techniques presented in this article use a combination of ceramic systems currently available to satisfy functional demands while achieving acceptable esthetics. A controlled series of steps, where the provisional restorative components are being replaced by the definitive ones is planned. The only difference between the provisional and definitive restorative components is the material used. The definitive restorations consisted of an implant-supported zirconium oxide framework. Individual pressed porcelain restorations were luted to the framework and a natural tooth.

CLINICAL SIGNIFICANCE

Provisional restorations allow an objective form of communication. Vertical and horizontal transitional lines can be effectively masked with appropriate treatment planning and a skilled ceramist. Many traditional dental laboratory steps may be eliminated or simplified without compromising the definitive restorations.
( J Esthet Restor Dent 22:7–17, 2010)