JOURNAL OF PHYCOLOGY, Issue 5 2005
Walter H. Adey
Lithothamnion tophiforme (Esper) Unger is a dominant, arctic, saxicolous species that extends southward, albeit with reduced cover, into the deeper colder waters of the North Atlantic subarctic, where it also occurs in significant rhodolith deposits with L. glaciale. The external appearance of L. tophiforme is distinctive, but typification, anatomy, reproduction, ecology, and biogeography have not been previously analyzed. These topics are now addressed, with extensive use of SEM, in comparison with other North Atlantic arctic and subarctic melobesioid genera and species. The species considered in this article comprise 95% of the coralline biomass of the colder North Atlantic and adjacent arctic (i.e. less than 12° C summer and less than 0° C winter). In the outer thallus region of coralline algae, crust extension proceeds, calcification develops, surface sloughing and grazing occur, and reproductive structures are initiated. Analysis of the ultrastructure of the outer thallus region (epithallium, meristem, and perithallium) of L. tophiforme shows distinctive generic similarities and specific differences from the other Lithothamnion species discussed here. Considerable generic differences from the Clathromorpum and Leptophytum species also encountered in the region considered are highlighted as well. We discuss the functional and taxonomic implications of these distinguishing features and recommend that they be more widely considered in future research on coralline algae to understand more fully the ecology and evolution of the Corallinales. [source]

ENVY'S NARRATIVE SCRIPTS: CYPRIAN, BASIL, AND THE MONASTIC SAGES ON THE ANATOMY AND CURE OF THE INVIDIOUS EMOTIONS

MODERN THEOLOGY, Issue 1 2009
PAUL M. BLOWERS
Incorporating Martha Nussbaum's work on the "intelligence" of human emotions in Greco-Roman moral philosophy, Robert Kaster's analysis of the "narrative scripts" of rivalrous emotions in antiquity, and René Girard's insights into the role of "mimetic desire" in human envy, this article explores the strategies of two major early Christian bishops, Cyprian and Basil of Caesarea, to "read" and to cure the variant scripts of envy and related invidious passions in concrete ecclesial contexts. The article also examines certain monastic theologians in late antiquity who aspired to preempt invidious passions by encouraging salutary scripts of competition in virtue that realized equality of honor in their respective communities. [source]

CLINICAL ANATOMY: APPLIED ANATOMY FOR STUDENTS AND JUNIOR DOCTORS.

ANZ JOURNAL OF SURGERY, Issue 10 2007
11th EDITION - BY HAROLD ELLIS
No abstract is available for this article. [source]

Doubles and Desire: Anatomies of masculinity in the later nineteenth century

ART HISTORY, Issue 5 2003
Anthea Callen
This article explores duality and splitting in representations of the male body, stressing as a crucial factor the issue of social class. Focusing on the ,golden age' of doubles in the 1880s and 1890s, my study crosses the boundaries between France and Britain, art and medicine, visual images and literature, to analyse François Sallé's monumental painting of male homosociality, The Anatomy Class at the Ecole des Beaux-Arts (1888); I suggest parallels with the male doubling identified in R.L. Stevenson's novella The Strange Case of Dr Jekyll and Mr Hyde (1886). Addressing representations of medical professionals, I position my material within nineteenth-century clinical discourse (Foucault), and propose readings that develop the medical gaze as an alternative visual economy to that of the modern Parisian flâneur. Linking anatomy and dissection to the performance of striptease, I argue that Sallé's painting represents a scene in which unsuppressed homoerotic pleasure allows the visibility of homosexual desire, and permeability of sexual categories. [source]

Spermatogenesis in Boccardiella hamata (Polychaeta: Spionidae) from the Sea of Japan: sperm formation mechanisms as characteristics for future taxonomic revision

ACTA ZOOLOGICA, Issue 4 2010
Arkadiy A. Reunov
Abstract Reunov, A.A., Yurchenko, O.V., Alexandrova, Y.N. and Radashevsky, V.I. 2009. Spermatogenesis in Boccardiella hamata (Polychaeta: Spionidae) from the Sea of Japan: sperm formation mechanisms as characteristics for future taxonomic revision. ,Acta Zoologica (Stockholm) 91: 477,456. To characterize novel features that will be useful in the discussion and validation of the spionid polychaete Boccardiella hamata from the Sea of Japan, the successive stages of spermatogenesis were described and illustrated. Spermatogonia, spermatocytes and early spermatids are aflagellar cells that develop synchronously in clusters united by a cytophore. At the middle spermatid stage, the clusters undergo disintegration and spermatids produce flagella and float separately in coelomic fluid as they transform into sperm. Spermatozoa are filiform. The ring-shaped storage platelets are located along the anterior nuclear area. The nucleus is cupped by a conical acrosome. A nuclear plate is present between the acrosome and nucleus. The nucleus is a cylinder with the implantation fossa throughout its length and with the anterior part of the flagellum inside the fossa. There is only one centriole, serving as a basal body of the flagellum, situated in close vicinity of the acrosomal area. A collar of four mitochondria is located under the nuclear base. The ultrastructure of B. hamata spermatozoa from the Sea of Japan appears to be close to that of B. hamata from Florida described by Rice (Microscopic Anatomy of Invertebrates, Wiley-Liss, Inc., New York, 1992), suggesting species identity of the samples from the two regions. However, more detailed study of Florida's B. hamata sperm is required for a reliable conclusion concerning the similarity of these two polychaetes. In addition to sperm structure, features such as the cytophore-assigned pattern of spermatogenic cell development, the synchronous pattern of cell divisions, the non-flagellate early spermatogenic stages, and the vesicle amalgamation that drives meiotic cell cytokinesis and spermatid diorthosis will likely be useful in future testing of the validity of B. hamata and sibling species throughout the world. [source]

Anatomy of an Ambush: Security Risks Facing International Humanitarian Assistance

DISASTERS, Issue 1 2005
Frederick M. Burkle Jr. MD
The 2003 war with Iraq has generated security concerns that present unique challenges to the practice of providing international humanitarian assistance during war and conflict. Objective research studies on security management are lacking. However, case studies have proven to be an important education and training tool to advance situational awareness of security risks. These challenges are illustrated by an analysis of the events surrounding the first ambush of, and assassination attempt on, a senior US aid official in Baghdad. Before deployment to conflict areas, especially those characterised by insurgent activity, humanitarian providers must realistically assess the threats to life and to the mission. They must obtain pre-deployment situational awareness education, security training and optimal protective equipment and vehicles. [source]

Anatomy and systematics of the minute syrnolopsine gastropods from Lake Tanganyika (Caenogastropoda, Cerithioidea, Paludomidae)

ACTA ZOOLOGICA, Issue 4 2008
Ellen E. Strong
Abstract The minute syrnolopsine gastropods endemic to Lake Tanganyika have been allied to a number of freshwater, marine and terrestrial groups as a consequence of superficial conchological similarity. Although early anatomical studies confirmed the cerithioid organization of this clade, their close relationship to other lake species was not consistently recognized. In several recent cladistic analyses based on molecular data, the higher taxonomic placement and sister group relationships of syrnolopsines have been unstable. The present analysis confirms that syrnolopsines possess a spermatophore-forming organ , a synapomorphy of the Paludomidae , corroborating their placement in this family. Consistent with the molecular data, syrnolopsine monophyly is supported by two characters that occur exclusively in this group (salivary gland ducts that bypass the nerve ring and a linear albumen gland). Several characters in Martelia tanganyicensis, the most diminutive syrnolopsine , are only evident in the smallest lake species thus far investigated (Bridouxia, Stormsia) namely reduction of ctenidial leaflets, sorting area, intestine length and number of statoconia. These features are interpreted as being correlated with reduction in size. Nevertheless, close examination reveals differences in detail that allow more refined hypotheses of homology and are consistent with their independent origin. [source]

Anatomy of a Pennine peat slide, Northern England

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2003
Dr. Jeff Warburton
Abstract This paper describes and analyses the structure and deposits of a large UK peat slide, located at Hart Hope in the North Pennines, northern England. This particular failure is unusual in that it occurred in the winter (February, 1995) and shows excellent preservation of the sedimentary structures and morphology, both at the failure scar and downstream. The slide was triggered by heavy rain and rapid snowmelt along the line of an active peatland stream flush. Detailed mapping of the slide area and downstream deposits demonstrate that the slide was initiated as a blocky mass that degenerated into a debris flow. The slide pattern was complex, with areas of extending and compressive movement. A wave-like motion may have been set up in the failure. Within the slide site there was relatively little variability in block size (b axis); however, downstream the block sizes decrease rapidly. Stability analysis suggests the area at the head of the scar is most susceptible to failure. A ,secondary' slide area is thought to have only been initiated once the main failure had occurred. Estimates of the velocity of the flowing peat mass as it entered the main stream channel indicate a flow velocity of approximately 10 m s,1, which rapidly decreases downstream. A sediment budget for the peat slide estimates the failed peat mass to be 30 800 t. However, sediment delivery to the stream channel was relatively low. About 37% of the failed mass entered the stream channel and, despite moving initially as debris flow, the amount of deposition along the stream course and on the downstream fan is small (only about 1%). The efficiency of fluvial systems in transporting the eroded peat is therefore high. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Anatomy of employment growth

ECONOMIC POLICY, Issue 34 2002
Pietro Garibaldi
Summary This paper studies net employment growth across 21 OECD economies since 1980, focusing on the wide range of experiences within the European Union. The initial composition of employment across sectors is relevant in a few countries, but can only partially account for cross-country differences in net employment growth. Institutions play a more important role. A policy package including low dismissal costs and low taxation is significantly associated with high net employment growth and can account for a substantial share of cross-country differences. While the Netherlands' employment miracle is largely accounted for by an increase in part-time jobs for women aged 25,49 in the services sector, we find that in the whole sample part-time jobs largely replace full-time jobs, and temporary jobs replace permanent jobs, with small net effects on hours worked. Continental Europe did not increase employment as much as other OECD countries until the mid-1990s, but later appears to be staging a resurgence of employment growth. We argue that this resurgence is not merely cyclical, is likely related to reforms, and may well be there to stay. [source]

Anatomy of an overfill: a reflection on the process

ENDODONTIC TOPICS, Issue 1 2007
ALAN H. GLUSKIN
The design and implementation of shaping, cleaning and sealing objectives in root canal therapy are fraught with real and potential pitfalls when the anatomic complexity of the space and technical considerations for its instrumentation, disinfection and obturation are contemplated. This review will focus on the genesis of results that lead to endodontic overfills. We will look at how the literature defines overfill and overextension; attempt to address the consensus opinion on the definition of working length; and determine the effects of shaping geometry on overfill as well as the biological impact of obturation materials that go beyond the root canal space. In addition, this manuscript will highlight evidence for the prevention of overfills as well as focus on the local factors that affect repair and healing. [source]

Posterior Quadrantic Epilepsy Surgery: Technical Variants, Surgical Anatomy, and Case Series

EPILEPSIA, Issue 8 2007
Roy Thomas Daniel
Summary:,Objective: Patients with intractable epilepsy due to extensive lesions involving the posterior quadrant (temporal, parietal, and occipital lobes) form a small subset of epilepsy surgery. This study was done with a view to analyze our experience with this group of patients and to define the changes in the surgical technique over the last 15 years. We also describe the microsurgical technique of the different surgical variants used, along with their functional neuroanatomy. Methods: In this series there were 13 patients with a median age of 17 years. All patients had extensive presurgical evaluation that provided concordant evidence localizing the lesion and seizure focus to the posterior quadrant. The objective of the surgery was to eliminate the effect of the epileptogenic tissue and preserve motor and sensory functions. Results: During the course of this study period of 15 years, the surgical procedure performed evolved toward incorporating more techniques of disconnection and minimizing resection. Three technical variants were thus utilized in this series, namely, (i) anatomical posterior quadrantectomy (APQ), (ii) functional posterior quadrantectomy (FPQ), and (iii) periinsular posterior quadrantectomy (PIPQ). After a median follow-up period of 6 years, 12/13 patients had Engel's Class I seizure outcome. Conclusion: The results of surgery for posterior quadrantic epilepsy have yielded excellent seizure outcomes in 92% of the patients in the series with no mortality or major morbidity. The incorporation of disconnective techniques in multilobar surgery has maintained the excellent results obtained earlier with resective surgery. [source]

Anatomy of executive deficit following ruptured anterior communicating artery aneurysm

EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2009
O. Martinaud
Background and purpose:, To evaluate behavioral and cognitive deficits following anterior communicating artery aneurysm rupture and determine critical lesion locations. Methods:, We investigated 74 patients with standardized cognitive tests and behavioral inventory. Two examiners rated MRI signal abnormalities in 51 predetermined regions of interest. Classification tree analysis was used to select regions associated with each cognitive deficit. Results:, Eleven patients presented behavioral executive deficits and 10 had cognitive executive deficit. Their presence depended on left hemisphere lesions only: (i) ventral striatum lesion was associated with behavioral executive deficit (P = 0.04), reduction of activities (P = 0.01), and hyperactivity (P = 0.02); (ii) superior frontal gyrus lesion, with cognitive executive deficit (P = 0.01), action initiation deficit (P = 0.02), and rule deduction deficit (P = 0.02); (iii) anterior half of centrum semiovale lesion, with Stroop inhibition deficit (P = 0.02); (iv) medial superior and middle frontal gyri lesions, with task coordination deficit (P = 0.01); and (v) middle frontal gyrus lesion, with words generation deficit (P = 0.02). Conclusion:, This study supports that (i) cognitive executive deficits depend mostly on lateral prefrontal lesions, (ii) with locations varying according to executive process, and (iii) behavioral executive deficits are mainly due to left ventral striatum lesion in post-aneurysmal damage. [source]

An Overview of the Anatomy of Crystal Plasticity Models

ADVANCED ENGINEERING MATERIALS, Issue 9 2009
Georges Cailletaud
Abstract Single crystals, polycrystals, and DS alloys can be modeled in the same framework by means of crystal plasticity. This paper wants to show the common features of the different approaches on the grain level, and the additional assumptions that are needed to derive polycrystal or DS models. Phenomenological rules are introduced for representing the hardening in the single crystal constitutive equations. Series of examples are given to illustrate the capabilities of the various approaches that are mainly related to the crystallographic character, and to the fact that the macroscopic yield locus is not predefined, but built from a collection of linear yield conditions. [source]

Anatomy of Primary Afferents and Projection Neurones in the Rat Spinal Dorsal Horn with Particular Emphasis on Substance P and the Neurokinin 1 Receptor

EXPERIMENTAL PHYSIOLOGY, Issue 2 2002
A. J. Todd
The dorsal horn of the spinal cord plays an important role in transmitting information from nociceptive primary afferent neurones to the brain; however, our knowledge of its neuronal and synaptic organisation is still limited. Nociceptive afferents terminate mainly in laminae I and II and some of these contain substance P. Many projection neurones are located in lamina I and these send axons to various parts of the brain, including the caudal ventrolateral medulla (CVLM), parabrachial area, periaqueductal grey matter and thalamus. The neurokinin 1 (NK1) receptor on which substance P acts is expressed by certain neurones in the dorsal horn, including approximately 80% of lamina I projection neurones. There is also a population of large NK1 receptor-immunoreactive neurones with cell bodies in laminae III and IV which project to the CVLM and parabrachial area. It has been shown that the lamina III/IV NK1 receptor-immunoreactive projection neurones are densely and selectively innervated by substance P-containing primary afferent neurones, and there is evidence that these afferents also target lamina I projection neurones with the receptor. Both types of neurone are innervated by descending serotoninergic axons from the medullary raphe nuclei. The lamina III/IV neurones also receive numerous synapses from axons of local inhibitory interneurones which contain GABA and neuropeptide Y, and again this input shows some specificity since post-synaptic dorsal column neurones which also have cell bodies in laminae III and IV receive few contacts from neuropeptide Y-containing axons. These observations indicate that there are specific patterns of synaptic connectivity within the spinal dorsal horn. [source]

Anatomy of Failure: Bush's Decision-Making Process and the Iraq War

FOREIGN POLICY ANALYSIS, Issue 3 2009
David Mitchell
The Bush administration's decision-making process leading to the invasion of Iraq in 2003 has been singled out for its many shortcomings: failure of intelligence; lack of debate concerning options; an insufficient invading force; and poor postwar planning. Contrary to the administration's claim that no one foresaw the difficulties of waging a war in Iraq, many concerns about the challenges the United States would face were raised inside and outside of government. Yet, none of this information had a significant effect on the decision-making process. This paper develops a decision-making model that integrates elements from the individual to the organizational level and explains how important information was marginalized, leading to a poor policy outcome. The model illustrates how the combined effects of the president's formal management style, anticipatory compliance on the part of key players, bureaucratic politics, and the intervening variable of the 9/11 terrorist attacks contributed to a defective decision-making process. [source]

Interpreting three-dimensional structures from two-dimensional images: a web-based interactive 3D teaching model of surgical liver anatomy

HPB, Issue 6 2009
Jodi L. Crossingham
Abstract Background:, Given the increasing number of indications for liver surgery and the growing complexity of operations, many trainees in surgical, imaging and related subspecialties require a good working knowledge of the complex intrahepatic anatomy. Computed tomography (CT), the most commonly used liver imaging modality, enhances our understanding of liver anatomy, but comprises a two-dimensional (2D) representation of a complex 3D organ. It is challenging for trainees to acquire the necessary skills for converting these 2D images into 3D mental reconstructions because learning opportunities are limited and internal hepatic anatomy is complicated, asymmetrical and variable. We have created a website that uses interactive 3D models of the liver to assist trainees in understanding the complex spatial anatomy of the liver and to help them create a 3D mental interpretation of this anatomy when viewing CT scans. Methods:, Computed tomography scans were imported into DICOM imaging software (OsiriXÔ) to obtain 3D surface renderings of the liver and its internal structures. Using these 3D renderings as a reference, 3D models of the liver surface and the intrahepatic structures, portal veins, hepatic veins, hepatic arteries and the biliary system were created using 3D modelling software (Cinema 4DÔ). Results:, Using current best practices for creating multimedia tools, a unique, freely available, online learning resource has been developed, entitled Visual Interactive Resource for Teaching, Understanding And Learning Liver Anatomy (VIRTUAL Liver) (http://pie.med.utoronto.ca/VLiver). This website uses interactive 3D models to provide trainees with a constructive resource for learning common liver anatomy and liver segmentation, and facilitates the development of the skills required to mentally reconstruct a 3D version of this anatomy from 2D CT scans. Discussion:, Although the intended audience for VIRTUAL Liver consists of residents in various medical and surgical specialties, the website will also be useful for other health care professionals (i.e. radiologists, nurses, hepatologists, radiation oncologists, family doctors) and educators because it provides a comprehensive resource for teaching liver anatomy. [source]

Strange Anatomy: Gertrude Stein and the Avant-Garde Embryo

HYPATIA, Issue 1 2006
Lynn M. Morgan
Today's personable, sanitized images of human embryos and fetuses require an audience that is literally and metaphorically distanced from dead specimens. Yet scientists must handle dead specimens to produce embryological knowledge, which only then can be transformed into beautiful photographs and talking fetuses. I begin with an account of Gertrude Stein's experience making a model of a fetal brain. Her tactile encounter is contrasted to the avant-garde artistic tradition that later came to dominate embryo imagery. This essay shows the embryo visualizations portrayed in a contemporary coffee-table book about gestational development to be a remarkable political achievement predicated, in part, on keeping hidden the unsavory details of anatomical technique that transform dead specimens into icons of life. [source]

Anatomy and ultrastructure of the reproductive organs in Dactylopodola typhle (Gastrotricha: Macrodasyida) and their possible functions in sperm transfer

INVERTEBRATE BIOLOGY, Issue 1 2008
Alexander Kieneke
Abstract. The reproductive anatomy of gastrotrichs is well known for several species, especially for the marine taxon Macrodasyida. However, there is little information on the reproductive organs and the modes of mating and sperm transfer in putative basal taxa, which is necessary for accurate reconstruction of the ground pattern of the Gastrotricha. We present the first detailed morphological investigation of the reproductive system of a putative basal gastrotrich, Dactylopodola typhle, using transmission and scanning electron microscopy, histology, and microscopic observations of living specimens. Dactylopodola typhle is a hermaphrodite that possesses paired female and male gonads, an unpaired uterus with an outlet channel that we call the cervix, and an additional accessory reproductive organ, the so-called caudal organ. We hypothesize that the hollow, secretory caudal organ serves for picking up autospermatozoa (self-sperm), for spermatophore formation, and finally for transferring the autospermatophore to a mating partner. The allospermatophore (foreign spermatophore) is stored within the uterus where fertilization occurs. We think that the mature and fertilized egg is released through the cervix and the dorsolateral female gonopore, and not by rupture of the body wall. Based on the morphology, we provide a plausible hypothesis for spermatophore formation and transfer in D. typhle. Preliminary phylogenetic considerations indicate that the stem species of Macrodasyida, perhaps that of all Gastrotricha, had paired ovaries and paired testes, an unpaired uterus, and only one accessory reproductive organ. [source]

Clinically Oriented Anatomy, 6th edn.

JOURNAL OF ANATOMY, Issue 4 2009
Simon H. Parson
No abstract is available for this article. [source]

Clinical Anatomy for Your Pocket

JOURNAL OF ANATOMY, Issue 6 2009
Ayeshea Zacharkiw
No abstract is available for this article. [source]

Human Sectional Anatomy , Atlas of body sections, CT and MRI images

JOURNAL OF ANATOMY, Issue 1 2008
Ayeshea Zacharkiw
No abstract is available for this article. [source]

Anatomy of the lactating human breast redefined with ultrasound imaging

JOURNAL OF ANATOMY, Issue 6 2005
D. T. Ramsay
Abstract The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast. The breasts of 21 fully lactating women (1,6 months post partum) were scanned using an ACUSON XP10 (5,10 MHz linear array probe). The number of main ducts was measured, ductal morphology was determined, and the distribution of glandular and adipose tissue was recorded. Milk ducts appeared as hypoechoic tubular structures with echogenic walls that often contained echoes. Ducts were easily compressed and did not display typical sinuses. All ducts branched within the areolar radius, the first branch occurring 8.0 ± 5.5 mm from the nipple. Duct diameter was 1.9 ± 0.6 mm, 2.0 ± 90.7 mm and the number of main ducts was 9.6 ± 2.9, 9.2 ± 2.9, for left and right breast, respectively. Milk ducts are superficial, easily compressible and echoes within the duct represent fat globules in breastmilk. The low number and size of the ducts, the rapid branching under the areola and the absence of sinuses suggest that ducts transport breastmilk, rather than store it. The distribution of adipose and glandular tissue showed wide variation between women but not between breasts within women. The proportion of glandular and fat tissue and the number and size of ducts were not related to milk production. This study highlights inconsistencies in anatomical literature that impact on breast physiology, breastfeeding management and ultrasound assessment. [source]

Immunohistochemistry of the canine vomeronasal organ

JOURNAL OF ANATOMY, Issue 3 2003
Article first published online: 2 SEP 200
The publisher regrets that in Volume 202, Issue 6 of the Journal of Anatomy, the article Immunohistochemistry of the canine vomeronasal organ by J. C. Dennis et al. was inadvertently printed in black and white. It appears in this issue of the Journal of Anatomy (pp 329338) as it was originally intended. [source]

Anatomy of the cystic artery arising from the gastroduodenal artery and its choledochal branch,a case report

JOURNAL OF ANATOMY, Issue 3 2000
A. K. SARKAR
Variations in the branching pattern of the common hepatic artery often occur and may be encountered during cholecystectomy. Variants of the cystic artery, its branches and relations with the biliary structures and blood vessels emphasise the importance of arterial dissection in biliary surgery. In this study, a rare variant of the cystic artery and its choledochal branch is described. The cystic artery arose from the gastroduodenal artery, passed anterior to structures in the free margin of lesser omentum and travelled a long distance before supplying the gall bladder. A long choledochal branch was noted accompanying the common bile duct. Surgical implications of this variation of the cystic and choledochal arteries are discussed. [source]

Recent Advances in Human Evolution Research

JOURNAL OF ANATOMY, Issue 1 2000
Article first published online: 13 DEC 200
This isssue of Journal of Anatomy contains review articles based on a Symposium held during a joint meeting of the Anatomical Society of Great Britain and Ireland, the Anatomical Society of South Africa and the Nederlandse Anatomen Vereniging on 15 April 1998 at Rolduc, The Netherlands. The Symposium has been edited by Professor Bernard Wood whose initial review constitutes an introduction to the succeeding articles. [source]

Distortion of Right Superior Pulmonary Vein Anatomy by Balloon Catheters as a Contributor to Phrenic Nerve Injury

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2009
YASUO OKUMURA M.D.
Introduction: Cryothermal, HIFU, and laser catheter-based balloon technologies have been developed to simplify ablation for AF. Initial enthusiasm for their widespread use has been dampened by phrenic nerve (PN) injury. The interaction between PN and pulmonary vein (PV) geometry contributing to PN injury is unclear. Methods and Results: After right thoracotomy, the PN course along the epicardial right atrial surface was mapped directly in 10 dogs. The location of the PN and its relationship with the right superior (RS) PV, and potential RSPV surface distortions after balloon inflation were established by electroanatomic mapping. In 5 dogs, the PN was captured within the RSPV, but could not be stimulated in the remaining 5 dogs. The distance between the RSPV and the PN was significantly shorter in the captured group than in the noncaptured group (6.3 ± 3.1 mm vs 10.2 ± 3.2 mm, P < 0.001). Importantly, 96% of the captured sites within the RSPV were observed at a distance >5 mm into the PV. The inflated balloon surface anteriorly extended 5.6 ± 3.7 mm outside the PV diameter, with distortion of anatomy narrowing the distance from the balloon surface to the PN to 4.8 ± 2.3 mm. (Distance of the original RSPV-to-PN: 9.4 ± 2.7 mm, P < 0.001.) Conclusion: PN injury with balloon technologies may stem from anatomic distortion of the PV orifice/PN relationship, through increasing contact or shortening the relative distance between the ablation site and the PN, even without displacement of the balloon into the PV. These data are important in the refinement of these technologies to improve procedural safety. [source]

Does Left Atrial Volume and Pulmonary Venous Anatomy Predict the Outcome of Catheter Ablation of Atrial Fibrillation?

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2009
IRENE HOF M.D.
Introduction: Preprocedural factors may be helpful in selecting patients with atrial fibrillation (AF) for treatment with catheter ablation and in making an assumption regarding their prognosis. The aims of this study were to investigate whether left atrial (LA) volume and pulmonary venous (PV) anatomy, evaluated by computed tomography (CT) prior to ablation, will predict AF recurrence following catheter ablation. Methods and Results: We included 146 patients (mean age 57 ± 11 years, 83% male) with symptomatic AF (55% paroxysmal, 18% persistent, 27% long-standing persistent). All patients underwent CT scanning prior to catheter ablation to evaluate LA volume and PV anatomy. Circumferential PV isolation was performed guided by Cartomerge electroanatomical mapping. The outcome was defined as complete success, improvement, or failure. After a mean follow-up of 19 ±7 months, complete success was achieved in 59 patients (40%), and 38 patients (26%) demonstrated improvement. LA volume was found to be an independent predictor of AF recurrence with an adjusted OR of 1.14 for every 10-mL increase in volume (95% CI 1.00,1.29, P = 0.047). PV variations were equally distributed among the different outcomes of the ablation procedure, and therefore univariate analysis did not identify PV anatomy as a predictor of outcome. Conclusion: LA volume is an independent predictor of AF recurrence after catheter ablation. Additionally, PV anatomy did not have any effect on the outcome. These findings suggest that an assessment of LA volume may be incorporated into the preprocedural evaluation of patients being considered for AF ablation. [source]

Clinical Application of PET/CT Fusion Imaging for Three-Dimensional Myocardial Scar and Left Ventricular Anatomy during Ventricular Tachycardia Ablation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2009
JING TIAN M.D., Ph.D.
Background: Image integration has the potential to display three-dimensional (3D) scar anatomy and facilitate substrate characterization for ventricular tachycardia (VT) ablation. However, the current generation of clinical mapping systems cannot display 3D left ventricle (LV) anatomy with embedded 3D scar reconstructions or allow display of border zone and high-resolution anatomic scar features. Objective: This study reports the first clinical experience with a mapping system allowing an integrated display of 3D LV anatomy with detailed 2D/3D scar and border zone reconstruction. Methods: Ten patients scheduled for VT ablation underwent contrast-enhanced computed tomography (CT) and Rubidium-82 perfusion/F-18 Fluorodeoxyglucose metabolic Positron Emission Tomography (PET) imaging to reconstruct 3D LV and scar anatomy. LV and scar models were co-registered using a 3D mapping system and analyzed with a 17-segment model. Metabolic thresholding was used to reconstruct the 3D border zone. Real-time display of CT images was performed during ablation. Results: Co-registration (error 4.3 ± 0.7 mm) allowed simultaneous visualization of 3D LV anatomy and embedded scar and guided additional voltage mapping. Segments containing homogenous or partial scar correlated in 94.4% and 85.7% between voltage maps and 3D PET scar reconstructions, respectively. Voltage-defined scar and normal myocardium had relative FDG uptakes of 40 ± 13% and 89 ± 30% (P < 0.05). The 3D border zone correlated best with a 46% metabolic threshold. Real-time display of registered high-resolution CT images allowed the simultaneous characterization of scar-related anatomic changes. Conclusion: Integration of PET/CT reconstruction allows simultaneous 3D display of myocardial scar and border zone embedded into the LV anatomy as well as the display of detailed scar anatomy. Multimodality imaging may enable a new image-guided approach to substrate-guided VT ablation. [source]

Anatomy and Physiology of the Right Interganglionic Nerve: Implications for the Pathophysiology of Inappropriate Sinus Tachycardia

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2008
JING ZHOU M.D.
Objective: To simulate inappropriate sinus tachycardia (IST) in experimental animals. Background: We recently found that epinephrine injected into the anterior right ganglionated plexi (ARGP) adjacent to the sinoatrial (SA) node induced an arrhythmia simulating IST. Methods: In 19 anesthetized dogs, via a right thoracotomy, the course of the interganglionic nerve (IGN) from the right stellate ganglion along the superior vena cava to the heart was delineated. High-frequency stimulation (HFS; 0.1 msec duration, 20 Hz, 4.5,9.3 V) was applied to IGN at the junction of innominate vein and SVC. Results: HFS of the IGN significantly increased the sinus rate (SR) (baseline: 156 ± 19 beats/minutes [bpm], 4.5 V: 191 ± 28 bpm*, 8.0 V: 207 ± 23 bpm*, 9.3 V: 216 ± 18 bpm*; *P < 0.01 compared to baseline) without significant changes in A-H interval or blood pressure. P-wave morphology, ice mapping, and noncontact mapping indicated that this tachycardia was sinus tachycardia. In 8 of 19 dogs, injecting hexamethonium (5 mg), a ganglionic blocker, into the ARGP attenuated the response elicited by IGN stimulation (baseline: 160 ± 21 bpm, 4.5 V: 172 ± 32 bpm, 8.0 V: 197 ± 32 bpm*, 9.3 V: 206 ± 26 bpm*; *P < 0.05 compared to baseline). In 19 of 19 animals, after formaldehyde injection into the ARGP, SR acceleration induced by IGN stimulation was markedly attenuated (baseline: 149 ± 17 bpm, 4.5 V: 151 ± 21 bpm, 8.0 V: 155 ± 23 bpm, 9.3 V: 167 ± 24 bpm*; *P < 0.05 compared to baseline). Conclusions: HFS of the IGN caused a selective and significant acceleration of the SR. A significant portion of IGN traverses the ARGP or synapses with the autonomic ganglia in the ARGP before en route to the SA node. Dysautonomia involving the IGN and/or ARGP may play an important role in IST. [source]

Atrial Anatomy and Imaging in Atrial Fibrillation Ablation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 2006
ANDREW D. McGAVIGAN M.B.Ch.B., M.D.
Catheter ablation of atrial fibrillation (AF) can be a technically challenging procedure, requiring detailed knowledge of the anatomy of the atria and thoracic veins to achieve successful cure of AF with a low complication rate. In this article, we review the anatomy relevant to AF ablation: the intraatrial septum, the pulmonary veins and left atrial antral region, the left atrial vestibule, the right atrium and related veins, and the esophagus. We focus on normal variations of anatomy and the role of the available imaging modalities in facilitating safe and effective ablation of this common and complex arrhythmia. [source]