62 research outputs found
To the Editors—Risk factors for complications in the implantation of epicardial pacemakers in neonates and infants
Permanent His-bundle Pacing in Pediatrics and Congenital Heart Disease
Permanent His-bundle pacing has been gaining popularity in the adult population requiring cardiac resynchronization therapy. Initial procedural challenges are being overcome, and this method of pacing has been shown to improve left ventricular function and heart failure symptoms secondary to ventricular dyssynchrony. Though the etiologies of ventricular dyssynchrony may differ in children and those with congenital heart disease than in adults with structurally normal hearts, His-bundle pacing may also be a preferred option in these groups to restore more physiologic electric conduction and improve ventricular function. We present a review of the current literature and suggested directions involving deploying permanent His-bundle pacing in the pediatric and congenital heart disease population
The Risk of Thromboembolic Complications in Fontan Patients with Atrial Flutter/fibrillation Treated with Electrical Cardioversion
Atrial flutter or fibrillation (AFF) remains a major chronic complication of the Fontan procedure. This complication further predisposes this patient population to thromboembolic events. However, the incidence of thromboembolic complications in Fontan patients with AFF prior to or acutely after electrical cardioversion is unknown. This study aimed to characterize the risk of post-cardioversion thromboembolic events in this population. We performed a retrospective medical record review of all patients with a history of Fontan operation treated with direct current cardioversion for AFF at Riley Children’s Hospital between June 1992 and March 2014. A total of 57 patients were identified and reviewed. A total of 216 episodes of AFF required electrical cardioversion. Patients were treated with anticoagulation/antiplatelet therapy in 86.1 % (N = 186) of AFF episodes. Right atrial or Fontan conduit clots were observed in 33 patients (57.9 %) with 61 episodes of AFF. Approximately half (49.2 %, N = 30) of these episodes were treated immediately with electrical cardioversion. Twenty-five of 33 (75.8 %) patients with intracardiac thrombi had an atriopulmonary Fontan. Five (15.2 %) patients with a lateral caval tunnel had clots in the Fontan conduit, and three (9.1 %) patients with right atrium to right ventricular outflow tract (RVOT) connections presented with right atrial mural thrombi. Nine of the 57 (15.8 %) patients had documented stroke, and three (5.3 %) patients had pulmonary emboli during follow-up, although none of these emboli were associated with electrical cardioversion. The risk of thrombus and thromboembolism associated with AFF is high in the Fontan population. However, the risk of thromboembolism associated with cardioversion in the setting of anticoagulation is very low
Patient and Procedural Correlates of Fluoroscopy Use During Catheter Ablation in the Pediatric and Congenital Electrophysiology Lab
ObjectiveTo identify factors associated with fluoroscopy use in pediatric and congenital heart disease (CHD) patients.DesignRetrospective cohort.SettingPediatric electrophysiology lab in a single tertiary‐care children's hospital.PatientsThree hundred eighty‐three patients who underwent electrophysiology study and ablation between January 2010 and December 2012.MethodsAblation procedures in which nonfluoroscopic navigation was employed were reviewed. Procedures using ≥10 minutes of fluoroscopy (high‐fluoroscopy time; HF) were compared with those using <10 minutes (low‐fluoroscopy time; LF). Group comparison of characteristics was made in the entire cohort and in CHD and anatomically normal heart subsets.ResultsDuring the study period, 416 ablation procedures were performed involving 471 substrates in 383 patients. Median fluoroscopy time was 6.7 minutes overall and 5.1 minutes with anatomically normal hearts. LF comprised 61% of all ablation and 69% of anatomically normal hearts. LF procedures were associated with anatomically normal hearts (93% vs. 63%; P < .0001). In anatomically normal hearts, HF was associated with accessory pathways (64% vs. 47%; P = .01), posteroseptal substrates (22% vs. 9%; P = .002), and ventricular substrates (12% vs. 1%; P < .0001). All cases of intra‐atrial reentrant tachycardia were HF. HF was associated with trans‐septal puncture (47% vs. 23%; P < .0001) though not when controlling for atrioventricular nodal reentrant tachycardia. LF was associated with cryoablation (56% vs. 17%; P < .0001).ConclusionsIn pediatric and congenital EP, ablation procedures using cryoablation and in patients with anatomically normal hearts are associated with LF. In accessory pathway ablation, HF was not associated with trans‐septal puncture.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111901/1/chd12213.pd
Permanent Nonselective His Bundle Pacing in an Adult with L-Transposition of the Great Arteries and Complete AV Block
We report the placement of a permanent transvenous nonselective His bundle pacing lead in conjunction with a transvenous pacemaker/implantable cardioverter-defibrillator in an adult with Levo-Transposition of the Great Arteries (L-TGA) and a stenotic coronary sinus (CS) ostium, which would not accommodate a transvenous left ventricular (LV) pacing lead. Nonselective His bundle pacing provided a nearly identical ventricular activation pattern in this previously unpaced patient. Many L-TGA patients will have an eventual need for permanent pacing and, given the challenges of CS cannulation, His bundle pacing may represent a preferred modality rather than pure morphologic LV pacing or surgical systemic ventricular lead placement to achieve optimal electrical synchrony
Management of Complications Caused By a Massive Left Ventricle Tumor in a Neonate
We report a case of a neonate born with a giant fibroma occupying the entirety of her left ventricle. Due to the extensive resection, her postoperative course was complicated by severely diminished left ventricular function and complete heart block necessitating extracorporeal support. Ultimately, cardiac resynchronization therapy was employed, after which the infant’s ventricular function gradually improved and she was successfully discharged to home
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Nerves projecting from the intrinsic cardiac ganglia of the pulmonary veins modulate sinoatrial node pacemaker function
Rationale: Autonomic nerves from sinoatrial node (SAN) ganglia are known to regulate SAN function. However, it is unclear whether remote pulmonary vein ganglia (PVG) also modulate SAN pacemaker rhythm.
Objective: To investigate whether in the mouse heart PVG modulate SAN function.
Methods and Results: In hearts from 45 C57BL and 7 Connexin40+/GFP mice, we used tyrosine-hydroxylase (TH) and choline-acetyltransferase (ChAT) immunofluorescence labeling to characterize adrenergic and cholinergic elements, repectively, within the PVG and SAN. PVG project postganglionic nerves to the SAN. TH and ChAT stained nerves, enter the SAN as an extensive, dense mesh-like neural network. Neurons in PVG are biphenotypic, containing ChAT and TH positive neurons. In Langendorff-perfused hearts, we compared effects of electrical stimulation of PVG, posterior (PRCVG) and anterior right vena cava ganglia (ARCVG) using 200-2000 ms trains of pulses (300μs, 0.2-0.6mA, 200Hz). Sympathetic and/or parasympathetic blockade was achieved using 0.5μM propranolol and 1μM atropine, respectively. Epicardial optical mapping of SAN activation was performed before, during and after ganglion stimulation. PVG stimulation increased the P-P interval by 36±9%; PRCVG stimulation increased the P-P interval by 42±11%. ARCVG stimulation produced no change. Propranolol perfusion increased the PVG stimulation effect to 43±13%. Atropine caused a 5±6% decrease. In optical mapping experiments of whole hearts and isolated atrial preparations, PVG stimulation shifted the origin of SAN discharges to varying locations.
Conclusions: PVG contain cholinergic, adrenergic and biphenotipic neurons whose axons project across the right atrium to richly innervate the SAN region and contribute significantly to regulation of SAN function.Zarzoso Muñoz, M.; Rysevaite, K.; Milstein, ML.; Calvo Saiz, CJ.; Kean, AC.; Atienza Fernández, F.; Pauza, DH.... (2013). Nerves projecting from the intrinsic cardiac ganglia of the pulmonary veins modulate sinoatrial node pacemaker function. Cardiovascular Research. 566-575. doi:10.1093/cvr/cvt081S566575Johnson, T. A., Gray, A. L., Lauenstein, J.-M., Newton, S. S., & Massari, V. J. (2004). Parasympathetic control of the heart. I. An interventriculo-septal ganglion is the major source of the vagal intracardiac innervation of the ventricles. Journal of Applied Physiology, 96(6), 2265-2272. doi:10.1152/japplphysiol.00620.2003Rysevaite, K., Saburkina, I., Pauziene, N., Noujaim, S. F., Jalife, J., & Pauza, D. H. (2011). Morphologic pattern of the intrinsic ganglionated nerve plexus in mouse heart. Heart Rhythm, 8(3), 448-454. doi:10.1016/j.hrthm.2010.11.019Yuan, B.-X., Ardell, J. L., Hopkins, D. A., & Armour, J. A. (1993). Differential cardiac responses induced by nicotine sensitive canine atrial and ventricular neurones. Cardiovascular Research, 27(5), 760-769. doi:10.1093/cvr/27.5.760Rysevaite, K., Saburkina, I., Pauziene, N., Vaitkevicius, R., Noujaim, S. F., Jalife, J., & Pauza, D. H. (2011). Immunohistochemical characterization of the intrinsic cardiac neural plexus in whole-mount mouse heart preparations. Heart Rhythm, 8(5), 731-738. doi:10.1016/j.hrthm.2011.01.013Pauza, D. H., Pauziene, N., Pakeltyte, G., & Stropus, R. (2002). Comparative quantitative study of the intrinsic cardiac ganglia and neurons in the rat, guinea pig, dog and human as revealed by histochemical staining for acetylcholinesterase. Annals of Anatomy - Anatomischer Anzeiger, 184(2), 125-136. doi:10.1016/s0940-9602(02)80005-xPauza, D. H., Skripka, V., & Pauziene, N. (2002). Morphology of the Intrinsic Cardiac Nervous System in the Dog: A Whole-Mount Study Employing Histochemical Staining with Acetylcholinesterase. Cells Tissues Organs, 172(4), 297-320. doi:10.1159/000067198Arora, R. C., Waldmann, M., Hopkins, D. A., & Armour, J. A. (2003). Porcine intrinsic cardiac ganglia. The Anatomical Record, 271A(1), 249-258. doi:10.1002/ar.a.10030Gatti, P. J., Johnson, T. A., & John Massari, V. (1996). Can neurons in the nucleus ambiguus selectively regulate cardiac rate and atrio-ventricular conduction? Journal of the Autonomic Nervous System, 57(1-2), 123-127. doi:10.1016/0165-1838(95)00104-2Zhuang, S., Zhang, Y., Mowrey, K. A., Li, J., Tabata, T., Wallick, D. W., … Mazgalev, T. N. (2002). Ventricular Rate Control by Selective Vagal Stimulation Is Superior to Rhythm Regularization by Atrioventricular Nodal Ablation and Pacing During Atrial Fibrillation. Circulation, 106(14), 1853-1858. doi:10.1161/01.cir.0000031802.58532.04CHEN, J., WASMUND, S. L., & HAMDAN, M. H. (2006). Back to the Future: The Role of the Autonomic Nervous System in Atrial Fibrillation. Pacing and Clinical Electrophysiology, 29(4), 413-421. doi:10.1111/j.1540-8159.2006.00362.xArmour, J. A. (2008). Potential clinical relevance of the ‘little brain’ on the mammalian heart. Experimental Physiology, 93(2), 165-176. doi:10.1113/expphysiol.2007.041178LAZZARA, R., SCHERLAG, B. J., ROBINSON, M. J., & SAMET, P. (1973). Selective In Situ Parasympathetic Control of the Canine Sinoatrial and Atrioventricular Nodes. Circulation Research, 32(3), 393-401. doi:10.1161/01.res.32.3.393Gray, A. L., Johnson, T. A., Ardell, J. L., & Massari, V. J. (2004). Parasympathetic control of the heart. II. A novel interganglionic intrinsic cardiac circuit mediates neural control of heart rate. Journal of Applied Physiology, 96(6), 2273-2278. doi:10.1152/japplphysiol.00616.2003Pappone, C., Santinelli, V., Manguso, F., Vicedomini, G., Gugliotta, F., Augello, G., … Alfieri, O. (2004). Pulmonary Vein Denervation Enhances Long-Term Benefit After Circumferential Ablation for Paroxysmal Atrial Fibrillation. Circulation, 109(3), 327-334. doi:10.1161/01.cir.0000112641.16340.c7MIQUEROL, L., MEYSEN, S., MANGONI, M., BOIS, P., VANRIJEN, H., ABRAN, P., … GROS, D. (2004). Architectural and functional asymmetry of the His–Purkinje system of the murine heart. Cardiovascular Research, 63(1), 77-86. doi:10.1016/j.cardiores.2004.03.007Jalife, J., Slenter, V. A., Salata, J. J., & Michaels, D. C. (1983). Dynamic vagal control of pacemaker activity in the mammalian sinoatrial node. Circulation Research, 52(6), 642-656. doi:10.1161/01.res.52.6.642Fedorov, V. V., Hucker, W. J., Dobrzynski, H., Rosenshtraukh, L. V., & Efimov, I. R. (2006). Postganglionic nerve stimulation induces temporal inhibition of excitability in rabbit sinoatrial node. American Journal of Physiology-Heart and Circulatory Physiology, 291(2), H612-H623. doi:10.1152/ajpheart.00022.2006Saburkina, I., & Pauza, D. H. (2006). Location and variability of epicardiac ganglia in human fetuses. Anatomy and Embryology, 211(6), 585-594. doi:10.1007/s00429-006-0110-4Slavíková, J., Kuncová, J., Reischig, J., & Dvořáková, M. (2003). Neurochemical Research, 28(3/4), 593-598. doi:10.1023/a:1022837810357Tan, A. Y., Li, H., Wachsmann-Hogiu, S., Chen, L. S., Chen, P.-S., & Fishbein, M. C. (2006). Autonomic Innervation and Segmental Muscular Disconnections at the Human Pulmonary Vein-Atrial Junction. Journal of the American College of Cardiology, 48(1), 132-143. doi:10.1016/j.jacc.2006.02.054Vaitkevicius, R., Saburkina, I., Rysevaite, K., Vaitkeviciene, I., Pauziene, N., Zaliunas, R., … Pauza, D. H. (2009). Nerve Supply of the Human Pulmonary Veins: An Anatomical Study. Heart Rhythm, 6(2), 221-228. doi:10.1016/j.hrthm.2008.10.027Mabe, A. M., & Hoover, D. B. (2009). Structural and functional cardiac cholinergic deficits in adult neurturin knockout mice. Cardiovascular Research, 82(1), 93-99. doi:10.1093/cvr/cvp029Beau, S. L., Hand, D. E., Schuessler, R. B., Bromberg, B. I., Kwon, B., Boineau, J. P., & Saffitz, J. E. (1995). Relative Densities of Muscarinic Cholinergic and β-Adrenergic Receptors in the Canine Sinoatrial Node and Their Relation to Sites of Pacemaker Activity. Circulation Research, 77(5), 957-963. doi:10.1161/01.res.77.5.957Mangoni, M. E., & Nargeot, J. (2008). Genesis and Regulation of the Heart Automaticity. Physiological Reviews, 88(3), 919-982. doi:10.1152/physrev.00018.2007Brack, K. E., Coote, J. H., & Ng, G. A. (2003). Interaction between direct sympathetic and vagus nerve stimulation on heart rate in the isolated rabbit heart. Experimental Physiology, 89(1), 128-139. doi:10.1113/expphysiol.2003.002654Levy, M. N., & Zieske, H. (1969). Autonomic control of cardiac pacemaker activity and atrioventricular transmission. Journal of Applied Physiology, 27(4), 465-470. doi:10.1152/jappl.1969.27.4.465Hartzell, H. C. (1988). Regulation of cardiac ion channels by catecholamines, acetylcholine and second messenger systems. Progress in Biophysics and Molecular Biology, 52(3), 165-247. doi:10.1016/0079-6107(88)90014-4LEVY, M. N., YANG, T., & WALLICK, D. W. (1993). Assessment of Beat-by-Beat Control of Heart Rate by the Autonomic Nervous System: Molecular Biology Techniques Are Necessary, But Not Sufficient. Journal of Cardiovascular Electrophysiology, 4(2), 183-193. doi:10.1111/j.1540-8167.1993.tb01222.xLevy, M. N. (1971). Brief Reviews. Circulation Research, 29(5), 437-445. doi:10.1161/01.res.29.5.437Ng, G. A., Brack, K. E., & Coote, J. H. (2001). Effects of Direct Sympathetic and Vagus Nerve Stimulation on the Physiology of the Whole Heart - A Novel Model of Isolated Langendorff Perfused Rabbit Heart with Intact Dual Autonomic Innervation. Experimental Physiology, 86(3), 319-329. doi:10.1113/eph8602146Goldberg, J. (1975). Intra-SA-nodal pacemaker shifts induced by autonomic nerve stimulation in the dog. American Journal of Physiology-Legacy Content, 229(4), 1116-1123. doi:10.1152/ajplegacy.1975.229.4.1116Shibata, N., Inada, S., Mitsui, K., Honjo, H., Yamamoto, M., Niwa, R., … Kodama, I. (2001). Pacemaker Shift in the Rabbit Sinoatrial Node in Response to Vagal Nerve Stimulation. Experimental Physiology, 86(2), 177-184. doi:10.1113/eph8602100Glukhov, A. V., Fedorov, V. V., Anderson, M. E., Mohler, P. J., & Efimov, I. R. (2010). Functional anatomy of the murine sinus node: high-resolution optical mapping of ankyrin-B heterozygous mice. American Journal of Physiology-Heart and Circulatory Physiology, 299(2), H482-H491. doi:10.1152/ajpheart.00756.2009Michaels, D. C., Matyas, E. P., & Jalife, J. (1987). Mechanisms of sinoatrial pacemaker synchronization: a new hypothesis. Circulation Research, 61(5), 704-714. doi:10.1161/01.res.61.5.704Boyett, M. (2000). The sinoatrial node, a heterogeneous pacemaker structure. Cardiovascular Research, 47(4), 658-687. doi:10.1016/s0008-6363(00)00135-8Lemery, R., Birnie, D., Tang, A. S. L., Green, M., & Gollob, M. (2006). Feasibility study of endocardial mapping of ganglionated plexuses during catheter ablation of atrial fibrillation. Heart Rhythm, 3(4), 387-396. doi:10.1016/j.hrthm.2006.01.009Pokushalov, E., Romanov, A., Shugayev, P., Artyomenko, S., Shirokova, N., Turov, A., & Katritsis, D. G. (2009). Selective ganglionated plexi ablation for paroxysmal atrial fibrillation. Heart Rhythm, 6(9), 1257-1264. doi:10.1016/j.hrthm.2009.05.018Scherlag, B. J., Nakagawa, H., Jackman, W. M., Yamanashi, W. S., Patterson, E., Po, S., & Lazzara, R. (2005). Electrical Stimulation to Identify Neural Elements on the Heart: Their Role in Atrial Fibrillation. Journal of Interventional Cardiac Electrophysiology, 13(S1), 37-42. doi:10.1007/s10840-005-2492-2Puodziukynas, A., Kazakevicius, T., Vaitkevicius, R., Rysevaite, K., Jokubauskas, M., Saburkina, I., … Pauza, D. H. (2012). Radiofrequency catheter ablation of pulmonary vein roots results in axonal degeneration of distal epicardial nerves. Autonomic Neuroscience, 167(1-2), 61-65. doi:10.1016/j.autneu.2012.01.001Bauer, A., Deisenhofer, I., Schneider, R., Zrenner, B., Barthel, P., Karch, M., … Schmidt, G. (2006). Effects of circumferential or segmental pulmonary vein ablation for paroxysmal atrial fibrillation on cardiac autonomic function. Heart Rhythm, 3(12), 1428-1435. doi:10.1016/j.hrthm.2006.08.025Armour, J. A. (2010). Functional anatomy of intrathoracic neurons innervating the atria and ventricles. Heart Rhythm, 7(7), 994-996. doi:10.1016/j.hrthm.2010.02.01
Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies
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