1
|
Gibson CM, Steinhubl S, Lakkireddy D, Turakhia MP, Passman R, Jones WS, Bunch TJ, Curtis AB, Peterson ED, Ruskin J, Saxon L, Tarino M, Tarakji KG, Marrouche N, Patel M, Harxhi A, Kaul S, Nikolovski J, Juan S, Wildenhaus K, Damaraju CV, Spertus JA. Does early detection of atrial fibrillation reduce the risk of thromboembolic events? Rationale and design of the Heartline study. Am Heart J 2023; 259:30-41. [PMID: 36642226 DOI: 10.1016/j.ahj.2023.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/03/2023] [Accepted: 01/07/2023] [Indexed: 05/11/2023]
Abstract
BACKGROUND The impact of using direct-to-consumer wearable devices as a means to timely detect atrial fibrillation (AF) and to improve clinical outcomes is unknown. METHODS Heartline is a pragmatic, randomized, and decentralized application-based trial of US participants aged ≥65 years. Two randomized cohorts include adults with possession of an iPhone and without a history of AF and those with a diagnosis of AF taking a direct oral anticoagulant (DOAC) for ≥30 days. Participants within each cohort are randomized (3:1) to either a core digital engagement program (CDEP) via iPhone application (Heartline application) and an Apple Watch (Apple Watch Group) or CDEP alone (iPhone-only Group). The Apple Watch Group has the watch irregular rhythm notification (IRN) feature enabled and access to the ECG application on the Apple Watch. If an IRN notification is issued for suspected AF then the study application instructs participants in the Apple Watch Group to seek medical care. All participants were "watch-naïve" at time of enrollment and have an option to either buy or loan an Apple Watch as part of this study. The primary end point is time from randomization to clinical diagnosis of AF, with confirmation by health care claims. Key secondary endpoint are claims-based incidence of a 6-component composite cardiovascular/systemic embolism/mortality event, DOAC medication use and adherence, costs/health resource utilization, and frequency of hospitalizations for bleeding. All study assessments, including patient-reported outcomes, are conducted through the study application. The target study enrollment is approximately 28,000 participants in total; at time of manuscript submission, a total of 26,485 participants have been enrolled into the study. CONCLUSION The Heartline Study will assess if an Apple Watch with the IRN and ECG application, along with application-facilitated digital health engagement modules, improves time to AF diagnosis and cardiovascular outcomes in a real-world environment. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT04276441.
Collapse
Affiliation(s)
| | | | | | - Mintu P Turakhia
- Center for Digital Health, Stanford University School of Medicine, Stanford, CA; Veterans Affairs Health Palo Alto Health Care System, Palo Alto, CA
| | - Rod Passman
- Northwestern University Feinberg School of Medicine, Chicago, IL
| | - W Schuyler Jones
- Department of Medicine, Duke University School of Medicine, Durham, NC
| | - T Jared Bunch
- Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT
| | - Anne B Curtis
- Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY
| | - Eric D Peterson
- Department of Medicine, Duke University School of Medicine, Durham, NC
| | - Jeremy Ruskin
- Harvard Medical School, Massachusetts General Hospital, Boston, MA
| | - Leslie Saxon
- Keck School of Medicine, University of Southern California, Los Angeles, CA
| | | | | | | | | | - Ante Harxhi
- Janssen Scientific Affairs, LLC, Titusville, NJ
| | | | | | | | | | | | - John A Spertus
- Saint Luke's Mid America Heart Institute/University of Missouri-Kansas City, Kansas City, MO
| |
Collapse
|
2
|
Saxon L, Faulk RT, Barrett T, McLelland S, Boberg J. A Novel Digital Research Methodology for Continuous Health Assessment of the Special Operations Warfighter: The Digital cORA Study. J Spec Oper Med 2022; 22:78-82. [PMID: 36525017 DOI: 10.55460/4ssj-ahib] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
The role of US Special Operations Forces (SOF) globally has expanded greatly in the past 20 years, leaving SOF serving multiple deployments with little time or ability to recover in between. Currently, assessments of the health and human performance capabilities of these individuals are episodic, precluding an accurate assessment of physical and mental load over time, and leading to high rates of acute and chronic injury to the mind and body. The collection of personal health-related continuous datasets has recently been made feasible with the advancement of digital technologies. These comprehensive data allow for improved assessment, and consequently better results, partly due to the warfighters' real-time access to their data. Such information allows Soldiers to engage in their own health optimization. This article describes a research platform that allows for collection of data via a custom-made secure mobile application that extends the type, scope, and frequency of data collection beyond what is feasible during an in-person encounter. By digitizing existing assessments and by incorporating additional physical, neurocognitive, psychological, and lifestyle assessments, the platform provides individuals with the ability to better understand their mental and physical load, as well as reserve. The results of this interactive exchange may help to preserve the health of users as well as the stability and readiness of units.
Collapse
|
3
|
Cleland JGF, Bristow MR, Freemantle N, Olshansky B, Gras D, Saxon L, Tavazzi L, Boehmer J, Ghio S, Feldman AM, Daubert JC, deMets D. The Effect of Cardiac Resynchronization without a Defibrillator on Morbidity and Mortality: An Individual-Patient-Data Meta-Analysis of COMPANION and CARE-HF. Eur J Heart Fail 2022; 24:1080-1090. [PMID: 35490339 PMCID: PMC9543287 DOI: 10.1002/ejhf.2524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) reduces morbidity and mortality for patients with heart failure, reduced left ventricular ejection fraction, QRS duration >130 ms and in sinus rhythm. OBJECTIVES To identify patient-characteristics that predict the effect, specifically, of CRT-pacemakers (CRT-P) on all-cause mortality or the composite of hospitalisation for heart failure or all-cause mortality. METHODS An individual patient-data meta-analysis of the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) and Cardiac Resynchronization - Heart Failure (CARE-HF) trials. Only patients assigned to CRT-P or control (n = 1738) were included in order to avoid confounding from concomitant defibrillator therapy. The influence of baseline characteristics on treatment effects was investigated. RESULTS Median age was 67 (59-73) years, most patients were men (70%), 68% had a QRS duration of 150-199 ms and 80% had left bundle branch block (LBBB). Patients assigned to CRT-P had lower rates for all-cause mortality (HR 0.68 (95% CI 0.56 to 0.81; p < 0.0001) and the composite outcome (HR 0.67 (95% CI 0.58 to 0.78; p < 0.0001). No pre-specified characteristic, including sex, aetiology of ventricular dysfunction, QRS duration (within the studied range) or morphology or PR interval significantly influenced the effect of CRT-P on all-cause mortality or the composite outcome. However, CRT-P had a greater effect on the composite outcome for patients with lower body surface area (BSA) and those prescribed beta-blockers. CONCLUSIONS CRT-P reduces morbidity and mortality in appropriately selected patients with heart failure. Benefits may be greater in smaller patients and in those receiving beta-blockers. Neither QRS duration nor morphology independently predicted the benefit of CRT-P.
Collapse
Affiliation(s)
- John G F Cleland
- Robertson Centre for Biostatistics & Clinical Trials, University of Glasgow & National Heart & Lung Institute, Imperial College, London, UK
| | - Michael R Bristow
- University of Colorado Cardiovascular Institute, Aurora and Boulder, Colorado, USA
| | - Nicholas Freemantle
- Institute of Clinical Trials and Methodology, University College London, 90 High Holborn, London, UK
| | - Brian Olshansky
- University of Iowa, Iowa City & Mercy Hospital - North Iowa, Mason City, Iowa, USA
| | | | - Leslie Saxon
- Keck School of Medicine, University of Southern California
| | - Luigi Tavazzi
- Maria Cecilia Hospital - GVM Care & Cotignola, Italy
| | - John Boehmer
- Penn State Hershey Medical Center, Hershey, Pennsylvania, United States
| | - Stefano Ghio
- Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
| | - Arthur M Feldman
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | | | - David deMets
- University of Wisconsin School of Medicine and Public Health, Madison, WI
| |
Collapse
|
4
|
Barrett TJ, Sobhani M, Fox GR, Files B, Patitsas N, Duhaime J, Ebert R, Faulk R, Saxon L. Diverse predictors of early attrition in an elite marine training school. Military Psychology 2021. [DOI: 10.1080/08995605.2021.1993721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Trevor J. Barrett
- University of Southern California, Center for Body Computing, Institute for Creative Technologies, California
| | - Mona Sobhani
- University of Southern California, Center for Body Computing, Institute for Creative Technologies, California
| | - Glenn R. Fox
- Marshall School of Business, University of Southern California, Los Angeles, California
| | - Benjamin Files
- US Army Combat Capabilities Development Command, Army Research Laboratory West, Maryland
| | - Nicholas Patitsas
- Sol Price School of Public Policy, University of Southern California, Los Angeles, California
| | - Josiah Duhaime
- University of Southern California, Center for Body Computing, Institute for Creative Technologies, California
| | - Rebecca Ebert
- University of Southern California, Center for Body Computing, Institute for Creative Technologies, California
| | - Rob Faulk
- University of Southern California, Center for Body Computing, Institute for Creative Technologies, California
| | - Leslie Saxon
- University of Southern California, Center for Body Computing, Institute for Creative Technologies, California
| |
Collapse
|
5
|
Nikolovski J, Koldijk M, Weverling GJ, Spertus J, Turakhia M, Saxon L, Gibson M, Whang J, Sarich T, Zambon R, Ezeanochie N, Turgiss J, Jones R, Stoddard J, Burton P, Navar AM. Factors indicating intention to vaccinate with a COVID-19 vaccine among older U.S. adults. PLoS One 2021; 16:e0251963. [PMID: 34029345 PMCID: PMC8143399 DOI: 10.1371/journal.pone.0251963] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/06/2021] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The success of vaccination efforts to curb the COVID-19 pandemic will require broad public uptake of immunization and highlights the importance of understanding factors associated with willingness to receive a vaccine. METHODS U.S. adults aged 65 and older enrolled in the HeartlineTM clinical study were invited to complete a COVID-19 vaccine assessment through the HeartlineTM mobile application between November 6-20, 2020. Factors associated with willingness to receive a COVID-19 vaccine were evaluated using an ordered logistic regression as well as a Random Forest classification algorithm. RESULTS Among 9,106 study participants, 81.3% (n = 7402) responded and had available demographic data. The majority (91.3%) reported a willingness to be vaccinated. Factors most strongly associated with vaccine willingness were beliefs about the safety and efficacy of COVID-19 vaccines and vaccines in general. Women and Black or African American respondents reported lower willingness to vaccinate. Among those less willing to get vaccinated, 66.2% said that they would talk with their health provider before making a decision. During the study, positive results from the first COVID-19 vaccine outcome study were released; vaccine willingness increased after this report. CONCLUSIONS Even among older adults at high-risk for COVID-19 complications who are participating in a longitudinal clinical study, 1 in 11 reported lack of willingness to receive COVID-19 vaccine in November 2020. Variability in vaccine willingness by gender, race, education, and income suggests the potential for uneven vaccine uptake. Education by health providers directed toward assuaging concerns about vaccine safety and efficacy can help improve vaccine acceptance among those less willing. TRIAL REGISTRATION Clinicaltrials.gov NCT04276441.
Collapse
Affiliation(s)
- Janeta Nikolovski
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | - Martin Koldijk
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | - Gerrit Jan Weverling
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | - John Spertus
- Department of Internal Medicine, University of Missouri-Kansas City, Kansas City, MO, United States of America
| | - Mintu Turakhia
- Department of Medicine, Stanford University, Palo Alto, CA, United States of America
| | - Leslie Saxon
- Department of Medicine, University of Southern California, Los Angeles, CA, United States of America
| | - Mike Gibson
- Department of Medicine, Harvard, Boston, MA, United States of America
| | - John Whang
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | - Troy Sarich
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | - Robert Zambon
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | | | | | - Robyn Jones
- Johnson & Johnson, New Brunswick, NJ, United States of America
| | - Jeff Stoddard
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | - Paul Burton
- Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ, United States of America
| | - Ann Marie Navar
- Department of Medicine, UT Southwestern Medical Center, Dallas, TX, United States of America
| |
Collapse
|
6
|
Saxon L, DiPaula B, Fox GR, Ebert R, Duhaime J, Nocera L, Tran L, Sobhani M. Continuous Measurement of Reconnaissance Marines in Training With Custom Smartphone App and Watch: Observational Cohort Study. JMIR Mhealth Uhealth 2020; 8:e14116. [PMID: 32348252 PMCID: PMC7324996 DOI: 10.2196/14116] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 11/05/2019] [Accepted: 01/24/2020] [Indexed: 01/07/2023] Open
Abstract
Background Specialized training for elite US military units is associated with high attrition due to intense psychological and physical demands. The need to graduate more service members without degrading performance standards necessitates the identification of factors to predict success or failure in targeted training interventions. Objective The aim of this study was to continuously quantify the mental and physical status of trainees of an elite military unit to identify novel predictors of success in training. Methods A total of 3 consecutive classes of a specialized training course were provided with an Apple iPhone, Watch, and specially designed mobile app. Baseline personality assessments and continuous daily measures of mental status, physical pain, heart rate, activity, sleep, hydration, and nutrition were collected from the app and Watch data. Results A total of 115 trainees enrolled and completed the study (100% male; age: mean 22 years, SD 4 years) and 64 (55.7%) successfully graduated. Most training withdrawals (27/115, 23.5%) occurred by day 7 (mean 5.5 days, SD 3.4 days; range 1-22 days). Extraversion, positive affect personality traits, and daily psychological profiles were associated with course completion; key psychological factors could predict withdrawals 1-2 days in advance (P=.009). Conclusions Gathering accurate and continuous mental and physical status data during elite military training is possible with early predictors of withdrawal providing an opportunity for intervention.
Collapse
Affiliation(s)
- Leslie Saxon
- University of Southern California, Center for Body Computing, Keck School of Medicine, Playa Vista, CA, United States
| | - Brooks DiPaula
- University of Southern California, Center for Body Computing, Keck School of Medicine, Playa Vista, CA, United States
| | - Glenn R Fox
- University of Southern California, Center for Body Computing, Keck School of Medicine, Playa Vista, CA, United States.,University of Southern California, Marshall School of Business, Los Angeles, CA, United States
| | - Rebecca Ebert
- University of Southern California, Center for Body Computing, Keck School of Medicine, Playa Vista, CA, United States
| | - Josiah Duhaime
- United States Marine Corps, Reconnaissance Training Company, Camp Pendleton, CA, United States
| | - Luciano Nocera
- University of Southern California, Department of Computer Science, Viterbi School of Engineering, Los Angeles, CA, United States
| | - Luan Tran
- University of Southern California, Department of Computer Science, Viterbi School of Engineering, Los Angeles, CA, United States
| | - Mona Sobhani
- University of Southern California, Center for Body Computing, Keck School of Medicine, Playa Vista, CA, United States
| |
Collapse
|
7
|
Talmor G, Nguyen B, Keibel A, Temelkovska T, Saxon L. Use of software applications to improve medication adherence and achieve more integrated disease management in heart failure. Trends Cardiovasc Med 2018; 28:483-488. [PMID: 29699854 DOI: 10.1016/j.tcm.2018.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/08/2018] [Accepted: 04/03/2018] [Indexed: 10/17/2022]
Abstract
The treatment and management of heart failure is associated with high mortality rates and treatment costs. Poor medication adherence is a major barrier to improving care and traditional interventions addressing non-adherence have not consistently demonstrated improvement in health care outcomes like readmission. The reasons for non-adherence are complicated and illustrate the broader challenges patients face when managing a complex disease like heart failure. In this review, a digitally enabled heart failure management platform consisting of medical digital tools and software solutions that are designed to be patient-facing and continuously accessed is explored as a way to integrate the multiple components of heart failure care and deliver personalized patient management tools.
Collapse
Affiliation(s)
- Guy Talmor
- USC Center for Body Computing, Keck School of Medicine of the University of Southern California, HCC1 300N, 12015 Waterfront Dr. Playa Vista, CA, United States
| | - Benjamin Nguyen
- USC Center for Body Computing, Keck School of Medicine of the University of Southern California, HCC1 300N, 12015 Waterfront Dr. Playa Vista, CA, United States
| | - Andrew Keibel
- USC Center for Body Computing, Keck School of Medicine of the University of Southern California, HCC1 300N, 12015 Waterfront Dr. Playa Vista, CA, United States
| | - Tijana Temelkovska
- USC Center for Body Computing, Keck School of Medicine of the University of Southern California, HCC1 300N, 12015 Waterfront Dr. Playa Vista, CA, United States
| | - Leslie Saxon
- USC Center for Body Computing, Keck School of Medicine of the University of Southern California, HCC1 300N, 12015 Waterfront Dr. Playa Vista, CA, United States.
| |
Collapse
|
8
|
Wolfson AM, Grazette L, Saxon L, Nazeer H, Shavelle DM, Jermyn R. Baseline diastolic pressure gradient and pressure reduction in chronic heart failure patients implanted with the CardioMEMS™ HF sensor. ESC Heart Fail 2018; 5:316-321. [PMID: 29498245 PMCID: PMC5933960 DOI: 10.1002/ehf2.12280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 01/20/2018] [Accepted: 02/01/2018] [Indexed: 12/22/2022] Open
Abstract
AIMS Remote haemodynamic monitoring (RHM) decreases hospitalization rates in patients with chronic heart failure (HF). Many patients with chronic HF develop pulmonary hypertension (PH) secondary to left heart disease with some acquiring combined pre-capillary and post-capillary PH (Cpc-PH). The efficacy of RHM in achieving pulmonary pressure reductions in patients with Cpc-PH vs. isolated post-capillary PH (Ipc-PH) is unknown. The purpose of this study is to evaluate whether a higher baseline diastolic pressure gradient (DPGbaseline ) measured at the time of CardioMEMS™ HF sensor implantation is associated with lower reductions in pulmonary artery diastolic pressures (PADP). METHODS AND RESULTS This was a retrospective analysis of 32 patients meeting clinical indications for CardioMEMS™ implantation. DPGbaseline categorized patients as Cpc-PH (DPG ≥ 7 mmHg) or Ipc-PH (DPG < 7 mmHg). Minimum achievable PADP (PADPmin ) and ∆PADP (PADPbaseline - PADPmin ) were determined. Pearson's correlation analysis and comparison of mean pressure changes were assessed. Median age was 69 years, and median left ventricular ejection fraction (LVEF) was 25%. Eight patients (25%) had a LVEF ≥40%. Twenty-five patients (78%) met criteria for Ipc-PH and seven (22%) for Cpc-PH. Neither PADPmin (ρ = 0.27; P = 0.13) nor ΔPADP (ρ = 0.07; P = 0.72) was correlated with DPGbaseline . A trend towards higher ΔPADP was seen in Cpc-PH vs. Ipc-PH patients (15.2 vs. 9.88 mmHg; P = 0.12). There was a moderate positive correlation between baseline PADP and ΔPADP [ρ = 0.55 (0.26-0.76); P < 0.001]. CONCLUSIONS Decreased PADP reduction was not seen in Cpc-PH vs. Ipc-PH patients. Higher PADPbaseline was associated with greater ΔPADP. Larger studies are needed to elaborate our findings.
Collapse
Affiliation(s)
- Aaron M Wolfson
- Division of Cardiovascular Medicine, University of Southern California, Los Angeles, CA, USA
| | - Luanda Grazette
- Division of Cardiovascular Medicine, University of Southern California, Los Angeles, CA, USA
| | - Leslie Saxon
- Division of Cardiovascular Medicine, University of Southern California, Los Angeles, CA, USA
| | - Haider Nazeer
- Department of Cardiology, Albany Medical College, Albany, NY, USA
| | - David M Shavelle
- Division of Cardiovascular Medicine, University of Southern California, Los Angeles, CA, USA
| | - Rita Jermyn
- Division of Cardiology, St Francis Hospital, Roslyn, NY, USA
| |
Collapse
|
9
|
Yousefian O, Carlson S, Keibel A, Doshi R, Saxon L. Effect of Atrial Fibrillation on Pulmonary Artery Pressures in Ambulatory Heart Failure Patients. J Card Fail 2017. [DOI: 10.1016/j.cardfail.2017.07.172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Steinberg JS, Varma N, Cygankiewicz I, Aziz P, Balsam P, Baranchuk A, Cantillon DJ, Dilaveris P, Dubner SJ, El-Sherif N, Krol J, Kurpesa M, La Rovere MT, Lobodzinski SS, Locati ET, Mittal S, Olshansky B, Piotrowicz E, Saxon L, Stone PH, Tereshchenko L, Turitto G, Wimmer NJ, Verrier RL, Zareba W, Piotrowicz R. 2017 ISHNE-HRS expert consensus statement on ambulatory ECG and external cardiac monitoring/telemetry. Heart Rhythm 2017; 14:e55-e96. [DOI: 10.1016/j.hrthm.2017.03.038] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Indexed: 12/18/2022]
|
11
|
Saxon L, Makhashvili N, Chikovani I, Seguin M, McKee M, Patel V, Bisson J, Roberts B. Coping strategies and mental health outcomes of conflict-affected persons in the Republic of Georgia. Epidemiol Psychiatr Sci 2017; 26:276-286. [PMID: 26804972 PMCID: PMC5419062 DOI: 10.1017/s2045796016000019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/05/2016] [Indexed: 11/12/2022] Open
Abstract
AIMS Adults who experienced the 1992 and 2008 armed conflicts in the Republic of Georgia were exposed to multiple traumatic events and stressors over many years. The aim was to investigate what coping strategies are used by conflict-affected persons in Georgia and their association with mental disorders. METHOD A cross-sectional survey was conducted with 3600 adults, representing internally displaced persons (IDPs) from conflicts in the 1990s (n = 1200) and 2008 (n = 1200) and former IDPs who returned to their homes after the 2008 conflict (n = 1200). Post-traumatic stress disorder, depression, anxiety and coping strategies were measured using the Trauma Screening Questionnaire, Patient Health Questionnaire-9, Generalised Anxiety and adapted version of the Brief Coping Inventory, respectively. Descriptive and multivariate regression analyses were used. RESULTS Coping strategies such as use of humour, emotional support, active coping, acceptance and religion were significantly associated with better mental health outcomes. Coping strategies of behavioural and mental disengagement, denial, venting emotions, substance abuse and gambling were significantly associated with poorer mental health outcomes. The reported use of coping strategies varied significantly between men and women for 8 of the 15 strategies addressed. CONCLUSIONS Many conflict-affected persons in Georgia are still suffering mental health problems years after the conflicts. A number of specific coping strategies appear to be associated with better mental health and should be encouraged and supported where possible.
Collapse
Affiliation(s)
- L. Saxon
- ECOHOST – The Centre for Health and Social Change, London School of Hygiene and Tropical Medicine, London, UK
| | - N. Makhashvili
- Global Initiative on Psychiatry, Tbilisi, Georgia
- Ilia State University, Tbilisi, Georgia
| | - I. Chikovani
- Curatio International Foundation, Tbilisi, Georgia
| | - M. Seguin
- ECOHOST – The Centre for Health and Social Change, London School of Hygiene and Tropical Medicine, London, UK
| | - M. McKee
- ECOHOST – The Centre for Health and Social Change, London School of Hygiene and Tropical Medicine, London, UK
| | - V. Patel
- Centre for Global Mental Health, London School of Hygiene and Tropical Medicine, London, UK
| | - J. Bisson
- Cardiff University School of Medicine, Cardiff and Vale University Health Board, Cardiff, UK
| | - B. Roberts
- ECOHOST – The Centre for Health and Social Change, London School of Hygiene and Tropical Medicine, London, UK
| |
Collapse
|
12
|
Wolfson AM, Yousefian O, Short L, O'Brien D, Talmor G, Qiu J, Yoon A, Fong M, Saxon L, Doshi R, Grazette L, Shavelle DM. Effects of pressure variation and atrial fibrillation on CardioMEMS ™ HF measured pulmonary artery diastolic pressure: comparison of device-averaged and visually inspected waveforms. Physiol Meas 2017; 38:1094-1103. [PMID: 28493849 DOI: 10.1088/1361-6579/aa6edb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Heart failure (HF) management guided by implantable hemodynamic monitoring reduces hospitalization rates. Hemodynamic data from the CardioMEMS™ HF system includes device-averaged pulmonary artery pressures (PAP) and heart rate. Agreement of device-averaged values compared to the standard method of visual inspection of pressure waveforms at end-expiration is unknown. We evaluated the agreement between device-averaged and visually inspected end-expiratory PAP. APPROACH Twenty-one patients implanted with the CardioMEMS™ HF system were evaluated. Eight-hundred twenty-three PAP waveforms from the Merlin remote monitoring website were visually inspected and pulmonary artery systolic pressure (PASP) and pulmonary artery diastolic pressure (PADP) at end-expiration were recorded. Waveforms were evaluated for pressure variation (PV), defined as the difference between highest and lowest PASP measurement of ⩾20 mmHg. Bland-Altman analysis quantified differences between device-averaged and visually inspected waveforms. MAIN RESULTS All patients were NYHA functional class III, mean age was 67 ± 15 years and 15 (71%) had AF. Bland-Altman analysis of all waveforms revealed a mean-difference in PADP of -1.4 mmHg, indicating that visually inspected values were higher than device-averaged values. For PV ⩾20 mmHg, this value increased to -2.8 mmHg. The mean-difference comparing waveforms from patients with or without AF was -1.3 and -1.6 mmHg, respectively. The 95% limits of agreement were >50% wider for waveforms from patients with versus without AF (10.3 versus 6.7 mmHg). SIGNIFICANCE There is good agreement between device-averaged and visually inspected waveforms when pressure variation is <20 mmHg and for patients without atrial fibrillation.
Collapse
Affiliation(s)
- Aaron M Wolfson
- Division of Cardiovascular Medicine, University of Southern California, Los Angeles, CA, United States of America
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Steinberg JS, Varma N, Cygankiewicz I, Aziz P, Balsam P, Baranchuk A, Cantillon DJ, Dilaveris P, Dubner SJ, El‐Sherif N, Krol J, Kurpesa M, La Rovere MT, Lobodzinski SS, Locati ET, Mittal S, Olshansky B, Piotrowicz E, Saxon L, Stone PH, Tereshchenko L, Turitto G, Wimmer NJ, Verrier RL, Zareba W, Piotrowicz R. 2017 ISHNE-HRS expert consensus statement on ambulatory ECG and external cardiac monitoring/telemetry. Ann Noninvasive Electrocardiol 2017; 22:e12447. [PMID: 28480632 PMCID: PMC6931745 DOI: 10.1111/anec.12447] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 02/06/2017] [Indexed: 02/06/2023] Open
Abstract
Ambulatory ECG (AECG) is very commonly employed in a variety of clinical contexts to detect cardiac arrhythmias and/or arrhythmia patterns which are not readily obtained from the standard ECG. Accurate and timely characterization of arrhythmias is crucial to direct therapies that can have an important impact on diagnosis, prognosis or patient symptom status. The rhythm information derived from the large variety of AECG recording systems can often lead to appropriate and patient-specific medical and interventional management. The details in this document provide background and framework from which to apply AECG techniques in clinical practice, as well as clinical research.
Collapse
Affiliation(s)
- Jonathan S. Steinberg
- Heart Research Follow‐up ProgramUniversity of Rochester School of Medicine & DentistryRochesterNYUSA
- The Summit Medical GroupShort HillsNJUSA
| | - Niraj Varma
- Cardiac Pacing & ElectrophysiologyDepartment of Cardiovascular MedicineCleveland ClinicClevelandOHUSA
| | | | - Peter Aziz
- Cardiac Pacing & ElectrophysiologyDepartment of Cardiovascular MedicineCleveland ClinicClevelandOHUSA
| | - Paweł Balsam
- 1st Department of CardiologyMedical University of WarsawWarsawPoland
| | | | - Daniel J. Cantillon
- Cardiac Pacing & ElectrophysiologyDepartment of Cardiovascular MedicineCleveland ClinicClevelandOHUSA
| | - Polychronis Dilaveris
- 1st Department of CardiologyUniversity of Athens Medical SchoolHippokration HospitalAthensGreece
| | - Sergio J. Dubner
- Arrhythmias and Electrophysiology ServiceClinic and Maternity Suizo Argentina and De Los Arcos Private HospitalBuenos AiresArgentina
| | | | - Jaroslaw Krol
- Department of Cardiology, Hypertension and Internal Medicine2nd Medical Faculty Medical University of WarsawWarsawPoland
| | - Malgorzata Kurpesa
- Department of CardiologyMedical University of LodzBieganski HospitalLodzPoland
| | | | | | - Emanuela T. Locati
- Cardiovascular DepartmentCardiology, ElectrophysiologyOspedale NiguardaMilanoItaly
| | | | | | - Ewa Piotrowicz
- Telecardiology CenterInstitute of CardiologyWarsawPoland
| | - Leslie Saxon
- University of Southern CaliforniaLos AngelesCAUSA
| | - Peter H. Stone
- Vascular Profiling Research GroupCardiovascular DivisionHarvard Medical SchoolBrigham & Women's HospitalBostonMAUSA
| | - Larisa Tereshchenko
- Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandORUSA
- Cardiovascular DivisionJohns Hopkins University School of MedicineBaltimoreMDUSA
| | - Gioia Turitto
- Weill Cornell Medical CollegeElectrophysiology ServicesNew York Methodist HospitalBrooklynNYUSA
| | - Neil J. Wimmer
- Vascular Profiling Research GroupCardiovascular DivisionHarvard Medical SchoolBrigham & Women's HospitalBostonMAUSA
| | - Richard L. Verrier
- Division of Cardiovascular MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolHarvard‐Thorndike Electrophysiology InstituteBostonMAUSA
| | - Wojciech Zareba
- Heart Research Follow‐up ProgramUniversity of Rochester School of Medicine & DentistryRochesterNYUSA
| | - Ryszard Piotrowicz
- Department of Cardiac Rehabilitation and Noninvasive ElectrocardiologyNational Institute of CardiologyWarsawPoland
| |
Collapse
|
14
|
Wu S, Fong M, Saxon L, Fox G, Wiggins L, Hackmann A. Predicting Outcomes in Patients Requiring Extracorporeal Membrane Oxygenation. J Heart Lung Transplant 2017. [DOI: 10.1016/j.healun.2017.01.926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
15
|
Abraham WT, Adamson PB, Costanzo MR, Eigler N, Gold M, Klapholz M, Maurer M, Saxon L, Singh J, Troughton R. Hemodynamic Monitoring in Advanced Heart Failure: Results from the LAPTOP-HF Trial. J Card Fail 2016. [DOI: 10.1016/j.cardfail.2016.09.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
16
|
Lin R, Chang P, Doshi R, Saxon L. Effects of Right Ventricular Versus Biventricular Pacing Following Transcatheter Aortic Valve Implantation. J Card Fail 2016. [DOI: 10.1016/j.cardfail.2016.06.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
17
|
Chang P, Saxon L, Doshi R. The Subcutaneous Implantable Cardioverter-Defibrillator as Part of Dual Device Therapy in Complex Congenital Heart Disease. J Innov Card Rhythm Manag 2016. [DOI: 10.19102/icrm.2016.070603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
18
|
Poulet B, de Souza R, Kent A, Saxon L, Barker O, Wilson A, Chang YM, Cake M, Pitsillides A. Intermittent applied mechanical loading induces subchondral bone thickening that may be intensified locally by contiguous articular cartilage lesions. Osteoarthritis Cartilage 2015; 23:940-8. [PMID: 25655679 PMCID: PMC4459965 DOI: 10.1016/j.joca.2015.01.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 01/19/2015] [Accepted: 01/23/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVES Changes in subchondral bone (SCB) and cross-talk with articular cartilage (AC) have been linked to osteoarthritis (OA). Using micro-computed tomography (micro-CT) this study: (1) examines changes in SCB architecture in a non-invasive loading mouse model in which focal AC lesions are induced selectively in the lateral femur, and (2) determines any modifications in the contralateral knee, linked to changes in gait, which might complicate use of this limb as an internal control. METHODS Right knee joints of CBA mice were loaded: once with 2 weeks of habitual use (n = 7), for 2 weeks (n = 8) or for 5 weeks (n = 5). Both left (contralateral) and right (loaded) knees were micro-CT scanned and the SCB and trabecular bone analysed. Gait analysis was also performed. RESULTS These analyses showed a significant increase in SCB thickness in the lateral compartments in joints loaded for 5 weeks, which was most marked in the lateral femur; the contralateral non-loaded knee also showed transient SCB thickening (loaded once and repetitively). Epiphyseal trabecular bone BV/TV and trabecular thickness were also increased in the lateral compartments after 5 weeks of loading, and in all joint compartments in the contralateral knee. Gait analysis showed that applied loading only affected gait in the contralateral himd-limb in all groups of mice from the second week after the first loading episode. CONCLUSIONS These data indicate a spatial link between SCB thickening and AC lesions following mechanical trauma, and the clear limitations associated with the use of contralateral joints as controls in such OA models, and perhaps in OA diagnosis.
Collapse
Affiliation(s)
- B. Poulet
- University College London, Royal Free Campus, London, UK
| | - R. de Souza
- Universidade Federal do Mato Grosso, Mato Grosso, Brazil
| | - A.V. Kent
- Royal Veterinary College, London, UK
| | - L. Saxon
- Royal Veterinary College, London, UK
| | - O. Barker
- Royal Veterinary College, London, UK
| | - A. Wilson
- Royal Veterinary College, London, UK
| | | | - M. Cake
- Murdoch University, Perth, Australia
| | - A.A. Pitsillides
- Royal Veterinary College, London, UK,Address correspondence and reprint requests to: A.A. Pitsillides, Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, University of London, NW1 0TU, UK. Tel: 44-207-468-5245.
| |
Collapse
|
19
|
Altaf F, Akar J, Lichtman J, Bao H, Jones P, Varosy P, Masoudi F, Stein K, Saxon L, Curtis J. VARIATIONS IN USE OF REMOTE MONITORING OF IMPLANTABLE DEFIBRILLATORS RELATIVE TO THE INTRODUCTION OF BILLING CODES SPECIFIC TO REMOTE MONITORING. J Am Coll Cardiol 2015. [DOI: 10.1016/s0735-1097(15)60459-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
20
|
Carlson S, Saxon L, Doshi R, Shinbane J, Chang P, Eisenberg E. Clinical Characteristics of Patients with Atrial Fibrillation on Long-term Ambulatory Monitoring. J Card Fail 2014. [DOI: 10.1016/j.cardfail.2014.06.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
21
|
Eisenberg E, Saxon L, Shinbane J, Chang P, Cao M, Kim D. Utility and diagnostic yield of long-term ambulatory patch ECG recording devices. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht310.p5585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
22
|
Daubert JC, Saxon L, Adamson PB, Auricchio A, Berger RD, Beshai JF, Breithard O, Brignole M, Cleland J, DeLurgio DB, Dickstein K, Exner DV, Gold M, Grimm RA, Hayes DL, Israel C, Leclercq C, Linde C, Lindenfeld J, Merkely B, Mont L, Murgatroyd F, Prinzen F, Saba SF, Shinbane JS, Singh J, Tang AS, Vardas PE, Wilkoff BL, Zamorano JL, Anand I, Blomström-Lundqvist C, Boehmer JP, Calkins H, Cazeau S, Delgado V, Estes NAM, Haines D, Kusumoto F, Leyva P, Ruschitzka F, Stevenson LW, Torp-Pedersen CT. 2012 EHRA/HRS expert consensus statement on cardiac resynchronization therapy in heart failure: implant and follow-up recommendations and management. Europace 2013; 14:1236-86. [PMID: 22930717 DOI: 10.1093/europace/eus222] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
23
|
Daubert JC, Saxon L, Adamson PB, Auricchio A, Berger RD, Beshai JF, Breithard O, Brignole M, Cleland J, Delurgio DB, Dickstein K, Exner DV, Gold M, Grimm RA, Hayes DL, Israel C, Leclercq C, Linde C, Lindenfeld J, Merkely B, Mont L, Murgatroyd F, Prinzen F, Saba SF, Shinbane JS, Singh J, Tang AS, Vardas PE, Wilkoff BL, Zamorano JL. 2012 EHRA/HRS expert consensus statement on cardiac resynchronization therapy in heart failure: implant and follow-up recommendations and management. Heart Rhythm 2012; 9:1524-76. [PMID: 22939223 DOI: 10.1016/j.hrthm.2012.07.025] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Indexed: 11/30/2022]
|
24
|
Abstract
Heart failure is a major public health concern that is frequently complicated by ventricular arrhythmias. Sustained ventricular tachycardia is associated with an increased risk for progressive heart failure and sudden death. We summarize the current management strategies for ventricular tachycardia in heart failure patients, including implantable cardioverter-defibrillator therapy, pharmacologic therapy, catheter ablation techniques, ventricular assist device therapy, and heart transplantation.
Collapse
Affiliation(s)
- Michael W Fong
- Division of Cardiovascular Medicine, Keck School of Medicine, University of Southern California, 1510 San Pablo Street, Suite 322, Los Angeles, CA 90033, USA.
| | | | | | | | | |
Collapse
|
25
|
Cesario DA, Powell B, Cao M, Saxon L, Day J, Wold N. ATRIAL FIBRILLATION AND OUTCOMES IN A LARGE COHORT OF CRT RECIPIENTS: RESULTS FROM THE ALTITUDE STUDY. J Am Coll Cardiol 2011. [DOI: 10.1016/s0735-1097(11)60153-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
26
|
Troughton RW, Ritzema J, Eigler NL, Melton IC, Krum H, Adamson PB, Kar S, Shah PK, Whiting JS, Heywood JT, Rosero S, Singh JP, Saxon L, Matthews R, Crozier IG, Abraham WT. Direct left atrial pressure monitoring in severe heart failure: long-term sensor performance. J Cardiovasc Transl Res 2010; 4:3-13. [PMID: 20945124 PMCID: PMC3018612 DOI: 10.1007/s12265-010-9229-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2010] [Accepted: 09/27/2010] [Indexed: 12/30/2022]
Abstract
We report the stability, accuracy, and development history of a new left atrial pressure (LAP) sensing system in ambulatory heart failure (HF) patients. A total of 84 patients with advanced HF underwent percutaneous transseptal implantation of the pressure sensor. Quarterly noninvasive calibration by modified Valsalva maneuver was achieved in all patients, and 96.5% of calibration sessions were successful with a reproducibility of 1.2 mmHg. Absolute sensor drift was maximal after 3 months at 4.7 mmHg (95% CI, 3.2–6.2 mmHg) and remained stable through 48 months. LAP was highly correlated with simultaneous pulmonary wedge pressure at 3 and 12 months (r = 0.98, average difference of 0.8 ± 4.0 mmHg). Freedom from device failure was 95% (n = 37) at 2 years and 88% (n = 12) at 4 years. Causes of failure were identified and mitigated with 100% freedom from device failure and less severe anomalies in the last 41 consecutive patients (p = 0.005). Accurate and reliable LAP measurement using a chronic implanted monitoring system is safe and feasible in patients with advanced heart failure.
Collapse
|
27
|
Shah M, Kola B, Bataveljic A, Arnett T, Viollet B, Saxon L, Korbonits M, Chenu C. AMP-activated protein kinase (AMPK) activation regulates in vitro bone formation and bone mass. Bone 2010; 47:309-19. [PMID: 20399918 PMCID: PMC3629687 DOI: 10.1016/j.bone.2010.04.596] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 04/09/2010] [Accepted: 04/10/2010] [Indexed: 02/06/2023]
Abstract
Adenosine 5'-monophosphate-activated protein kinase (AMPK), a regulator of energy homeostasis, has a central role in mediating the appetite-modulating and metabolic effects of many hormones and antidiabetic drugs metformin and glitazones. The objective of this study was to determine if AMPK can be activated in osteoblasts by known AMPK modulators and if AMPK activity is involved in osteoblast function in vitro and regulation of bone mass in vivo. ROS 17/2.8 rat osteoblast-like cells were cultured in the presence of AMPK activators (AICAR and metformin), AMPK inhibitor (compound C), the gastric peptide hormone ghrelin and the beta-adrenergic blocker propranolol. AMPK activity was measured in cell lysates by a functional kinase assay and AMPK protein phosphorylation was studied by Western Blotting using an antibody recognizing AMPK Thr-172 residue. We demonstrated that treatment of ROS 17/2.8 cells with AICAR and metformin stimulates Thr-172 phosphorylation of AMPK and dose-dependently increases its activity. In contrast, treatment of ROS 17/2.8 cells with compound C inhibited AMPK phosphorylation. Ghrelin and propranolol dose-dependently increased AMPK phosphorylation and activity. Cell proliferation and alkaline phosphatase activity were not affected by metformin treatment while AICAR significantly inhibited ROS 17/2.8 cell proliferation and alkaline phosphatase activity at high concentrations. To study the effect of AMPK activation on bone formation in vitro, primary osteoblasts obtained from rat calvaria were cultured for 14-17days in the presence of AICAR, metformin and compound C. Formation of 'trabecular-shaped' bone nodules was evaluated following alizarin red staining. We demonstrated that both AICAR and metformin dose-dependently increase trabecular bone nodule formation, while compound C inhibits bone formation. When primary osteoblasts were co-treated with AICAR and compound C, compound C suppressed the stimulatory effect of AICAR on bone nodule formation. AMPK is a alphabetagamma heterotrimer, where alpha is the catalytic subunit. RT-PCR analysis of AMPK subunits in ROS17/2.8 osteoblastic cells and in mouse tibia showed that the AMPKalpha1 subunit is the dominant isoform expressed in bone. We analysed the bone phenotype of 4month-old male wild type (WT) and AMPKalpha1-/- KO mice using micro-CT. Both cortical and trabecular bone compartments were smaller in the AMPK alpha1-deficient mice compared to the WT mice. Altogether, our data support a role for AMPK signalling in skeletal physiology.
Collapse
Affiliation(s)
- M. Shah
- Department of Veterinary Basic Sciences Royal Veterinary College, Royal College Street, London, NW1 OTU, UK
| | - B. Kola
- Department of Endocrinology Barts and the London Medical School, London, UK
| | - A. Bataveljic
- Department of Veterinary Basic Sciences Royal Veterinary College, Royal College Street, London, NW1 OTU, UK
| | - T.R. Arnett
- Department of Cell & Developmental Biology, University College London, London, UK
| | - B. Viollet
- Department of Endocrinology, Metabolism and Cancer, INSERM U567, CNRS UMR 8104, Université Paris Descartes, Paris, France
| | - L. Saxon
- Department of Veterinary Basic Sciences Royal Veterinary College, Royal College Street, London, NW1 OTU, UK
| | - M. Korbonits
- Department of Endocrinology Barts and the London Medical School, London, UK
| | - C. Chenu
- Department of Veterinary Basic Sciences Royal Veterinary College, Royal College Street, London, NW1 OTU, UK
- Corresponding author. Royal Veterinary College, Royal College Street, London NW1 OTU, UK. Fax: +44 207 468 5204. (C. Chenu)
| |
Collapse
|
28
|
Saxon L, Borg S, Hiltunen AJ. Reduction of aggression during benzodiazepine withdrawal: effects of flumazenil. Pharmacol Biochem Behav 2010; 96:148-51. [PMID: 20451546 DOI: 10.1016/j.pbb.2010.04.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Revised: 04/14/2010] [Accepted: 04/28/2010] [Indexed: 11/30/2022]
Abstract
Benzodiazepine withdrawal has been associated with hostile and aggressive behavior. The benzodiazepine antagonist flumazenil has reduced, increased or not affected hostility and aggression in animal and human studies. In the present study we analyzed data collected in a placebo-controlled study of the effects of the benzodiazepine antagonist flumazenil in patients previously treated for benzodiazepine dependency, and healthy controls. The aim was to analyze the effects of flumazenil on hostility and aggression. Ten patients and 10 controls received, on two separate occasions, cumulative doses of flumazenil (0.05, 0.1, 0.25, 0.5 and 1mg at 15min intervals) or placebo. Withdrawal symptoms were rated after each injection. Patients had been free from benzodiazepines for 47 (4-266) weeks on the first occasion. A three-way interaction (groupxtreatmentxdose) was found, and was explained by: 1) patients rating aggression and hostility higher than controls at all times during placebo, while 2) during the flumazenil provocation i) the initial significant difference between patients and controls was no longer significant above the 0.5mg dose, and ii) patients rated aggression and hostility significantly lower above the 0.5mg dose compared to base-line. The results suggest that self-rated aggression and hostility in patients treated for benzodiazepine dependency was reduced by the partial benzodiazepine agonist flumazenil.
Collapse
Affiliation(s)
- L Saxon
- Department of Clinical Neuroscience, Section of Dependency Research, Karolinska Institute, Stockholm, Sweden
| | | | | |
Collapse
|
29
|
Saxon L. Implant wizard. Interview by Gary Baldwin. Health Data Manag 2010; 18:40. [PMID: 20108819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
|
30
|
Ducher G, Bass S, Saxon L, Daly R. Can exercise-induced benefits in bone strength be further improved after menarche if training is maintained? J Sci Med Sport 2010. [DOI: 10.1016/j.jsams.2009.10.402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
31
|
Friedewald VE, Boehmer JP, Kowal RC, Saxon L, Yancy CW, Roberts WC. The editor's roundtable: Cardiac resynchronization therapy. Am J Cardiol 2007; 100:1145-52. [PMID: 17884379 DOI: 10.1016/j.amjcard.2007.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 07/17/2007] [Indexed: 11/19/2022]
Affiliation(s)
- Vincent E Friedewald
- Department of Internal Medicine, The University of Texas Medical School at Houston, Houston, Texas, USA.
| | | | | | | | | | | |
Collapse
|
32
|
Estes NM, Page R, Boyden P, Cappato R, Chiu-Man C, Day J, DiMarco J, Ferrick A, Hamdan M, Hamilton R, Hohnloser S, Jung W, Kanter R, Knight B, Lindsay B, Natale A, Reynolds D, Rosenbaum D, Saxon L, Shen WK, Trayanova N, Wilkoff B. Heart Rhythm Society Scientific Program Committee. Heart Rhythm 2007. [DOI: 10.1016/j.hrthm.2007.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
33
|
Lindenfeld J, Feldman AM, Saxon L, Boehmer J, Carson P, Ghali JK, Anand I, Singh S, Steinberg JS, Jaski B, DeMarco T, Mann D, Yong P, Galle E, Ecklund F, Bristow M. Effects of Cardiac Resynchronization Therapy With or Without a Defibrillator on Survival and Hospitalizations in Patients With New York Heart Association Class IV Heart Failure. Circulation 2007; 115:204-12. [PMID: 17190867 DOI: 10.1161/circulationaha.106.629261] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Cardiac resynchronization therapy (CRT) alone or combined with an implantable defibrillator (CRT-D) has been shown to improve exercise capacity and quality of life and to reduce heart failure (HF) hospitalizations and mortality in patients with New York Heart Association (NYHA) class III and IV HF. There is concern that the device procedure may destabilize these very ill class IV patients. We sought to examine the outcomes of NYHA class IV patients enrolled in the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) trial to assess the potential benefits of CRT and CRT-D.
Methods and Results—
The COMPANION trial randomized 1520 patients with NYHA class III and IV HF to optimal medical therapy, CRT, or CRT-D. In the class IV patients (n=217), the primary end point of time to death or hospitalization for any cause was significantly improved by both CRT (hazard ratio [HR], 0.64; 95% CI, 0.43 to 0.94;
P
=0.02) and CRT-D (HR, 0.62; 95% CI, 0.42 to 0.90;
P
=0.01). Time to all-cause death and HF hospitalization was also significantly improved in both CRT (HR, 0.57; 95% CI, 0.37 to 0.87;
P
=0.01) and CRT-D (HR, 0.49; 95% CI, 0.32 to 0.75;
P
=0.001) Time to all-cause death trended to an improvement in both CRT (HR, 0.67; 95% CI, 0.41 to 1.10;
P
=0.11) and CRT-D (HR, 0.63; 95% CI, 0.39 to 1.03;
P
=0.06). Time to sudden death appeared to be significantly reduced in the CRT-D group (HR, 0.27; 95% CI, 0.08 to 0.90;
P
=0.03). There was a nonsignificant reduction in time to HF deaths for both CRT (HR, 0.68; 95% CI, 0.34 to 1.37;
P
=0.28) and CRT-D (HR, 0.79; 95% CI, 0.41 to 1.52;
P
=0.48).
Conclusions—
CRT and CRT-D significantly improve time to all-cause mortality and hospitalizations in NYHA class IV patients, with a trend for improved mortality. These devices should be considered in ambulatory NYHA class IV HF patients similar to those enrolled in COMPANION.
Collapse
Affiliation(s)
- JoAnn Lindenfeld
- Department of Medicine, University of Colorado Health Sciences Center, 4200 E. Ninth Ave, Denver, CO 80262, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Dumville JC, Miles JNV, Porthouse J, Cockayne S, Saxon L, King C. Can vitamin D supplementation prevent winter-time blues? A randomised trial among older women. J Nutr Health Aging 2006; 10:151-3. [PMID: 16554952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
BACKGROUND Seasonal Affective Disorder (SAD) is a sub-type of depression that only occurs during the winter months. A reduction in vitamin D may be linked to SAD. Since vitamin D deficiency has been reported to be common in older people, vitamin D supplementation may be expected to reduce seasonal mood disturbance in this group. OBJECTIVE To assess the effect of vitamin D supplementation on the mental health of older women. SETTING Primary care in three areas of the UK (Herts, Newcastle, York). SUBJECTS Women aged 70 years or more recruited to the trial in the months May-October. INTERVENTION Eligible women were randomised to receive calcium and vitamin D supplementation or no supplementation. OUTCOME MEASURE At baseline and the six monthly assessment the mental component score (MCS), calculated from the SF-12 questionnaire was used to assess participants' subjective psychological well-being. RESULTS A total of 2117 women recruited to the trial had their baseline measures taken between the months of May-October (1205 woman in the control group and 912 women in the intervention group). Of these women, 1621 had a MCS score at baseline and six months. Comparison of the six month mean MCS scores, adjusting for baseline MCS score and age, showed there was no significant difference between the two scores (p = 0.262). CONCLUSIONS Supplementing elderly women with 800 IU of vitamin D daily did not lead to an improvement in mental health scores.
Collapse
Affiliation(s)
- J C Dumville
- Area 4, Seebohm Rowntree Building, Dept of Health Sciences, University of York, York YO10 5DD.
| | | | | | | | | | | |
Collapse
|
35
|
Warden S, Saxon L, Turner C. 367 The higher incidence of anterior cruciate ligament injuries in females is not due to direct ligament effects of estrogen. J Sci Med Sport 2005. [DOI: 10.1016/s1440-2440(17)30864-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
36
|
Saxon L. Delayed Defibrillation Testing After CRT-D Implant-Weighing Competing Risks. J Cardiovasc Electrophysiol 2005; 16:1284-5. [PMID: 16403057 DOI: 10.1111/j.1540-8167.2005.00275.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
37
|
Horwich T, Foster E, De Marco T, Tseng Z, Saxon L. Effects of Resynchronization Therapy on Cardiac Function in Pacemaker Patients “Upgraded” to Biventricular Devices. J Cardiovasc Electrophysiol 2004; 15:1284-9. [PMID: 15574179 DOI: 10.1046/j.1540-8167.2004.04279.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Cardiac resynchronization therapy (CRT) improves echocardiographic measures of cardiac function and has a variable effect on QRS duration in patients with left bundle branch block (LBBB). How CRT affects these indices in patients with right ventricular (RV) pacing-induced LBBB who are "upgraded" with left ventricular (LV) leads for CRT is unknown. We studied the echocardiographic effects of RV pacing and CRT in patients with prior continuous RV pacing after LV lead placement. METHODS AND RESULTS Fifteen consecutive patients (age 73 +/- 11 years, LV ejection fraction 24 +/- 6%, QRS duration 190 +/- 27 msec) with New York Heart Association class IIIB-IV symptoms and continuous RV pacing underwent LV lead placement for CRT. Echocardiography and ECG were performed sequentially during RV pacing and CRT. CRT was associated with significantly reduced QRS duration (190 +/- 27 msec vs 165 +/- 18 msec, P = 0.005) and reduced LV electromechanical delay (180 +/- 33 msec vs 161+/- 43 msec). Baseline QRS duration correlated with CRT response. After CRT, patients had significant improvements in indices of systolic function, including LV ejection fraction, myocardial performance index (MPI), and LV ejection time. Abnormal baseline MPI was associated with greater improvement after CRT. LV end-diastolic and systolic volumes were similarly decreased with CRT. Mitral valve deceleration time, an index of diastolic function, was not affected by CRT. CONCLUSION "Upgrading" RV paced patients with advanced heart failure to CRT improves measures of electrical and LV mechanical synchrony and improves systolic function.
Collapse
Affiliation(s)
- Tamara Horwich
- Division of Cardiology, UCLA School of Medicine, Los Angeles, California, USA
| | | | | | | | | |
Collapse
|
38
|
Haffajee C, Goel S, Botteron G, Van Genderen R, Saxon L. Early experience with new dual chamber biventricular ICD with the capability to detect and treat atrial and ventricular arrhythmias. J Card Fail 2004. [DOI: 10.1016/j.cardfail.2004.06.228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
39
|
Daly RM, Saxon L, Turner CH, Robling AG, Bass SL. The relationship between muscle size and bone geometry during growth and in response to exercise. Bone 2004; 34:281-7. [PMID: 14962806 DOI: 10.1016/j.bone.2003.11.009] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Revised: 10/23/2003] [Accepted: 11/03/2003] [Indexed: 11/21/2022]
Abstract
As muscles become larger and stronger during growth and in response to increased loading, bones should adapt by adding mass, size, and strength. In this unilateral model, we tested the hypothesis that (1) the relationship between muscle size and bone mass and geometry (nonplaying arm) would not change during different stages of puberty and (2) exercise would not alter the relationship between muscle and bone, that is, additional loading would result in a similar unit increment in both muscle and bone mass, bone size, and bending strength during growth. We studied 47 competitive female tennis players aged 8-17 years. Total, cortical, and medullary cross-sectional areas, muscle area, and the polar second moment of area (I(p)) were calculated in the playing and nonplaying arms using magnetic resonance imaging (MRI); BMC was assessed by DXA. Growth effects: In the nonplaying arm in pre-, peri- and post-pubertal players, muscle area was linearly associated BMC, total and cortical area, and I(p) (r = 0.56-0.81, P < 0.09 to < 0.001), independent of age. No detectable differences were found between pubertal groups for the slope of the relationship between muscle and bone traits. Post-pubertal players, however, had a higher BMC and cortical area relative to muscle area (i.e., higher intercept) than pre- and peri-pubertal players (P < 0.05 to < 0.01), independent of age; pre- and peri-pubertal players had a greater medullary area relative to muscle area than post-pubertal players (P < 0.05 to < 0.01). Exercise effects: Comparison of the side-to-side differences revealed that muscle and bone traits were 6-13% greater in the playing arm in pre-pubertal players, and did not increase with advancing maturation. In all players, the percent (and absolute) side-to-side differences in muscle area were positively correlated with the percent (and absolute) differences in BMC, total and cortical area, and I(p) (r = 0.36-0.40, P < 0.05 to < 0.001). However, the side-to-side differences in muscle area only accounted for 11.8-15.9% of the variance of the differences in bone mass, bone size, and bending strength. This suggests that other factors associated with loading distinct from muscle size itself contributed to the bones adaptive response during growth. Therefore, the unifying hypothesis that larger muscles induced by exercise led to a proportional increase in bone mass, bone size, and bending strength appears to be simplistic and denies the influence of other factors in the development of bone mass and bone shape.
Collapse
Affiliation(s)
- R M Daly
- Centre for Physical Activity and Nutrition, School of Health Sciences, Deakin University, Melbourne, Australia.
| | | | | | | | | |
Collapse
|
40
|
Horwich T, Foster E, Tseng Z, Saxon L. Acute effects of cardiac resynchronization therapy on doppler echocardiographic variables of cardiac function in patients “upgraded” from right to biventricular devices. J Card Fail 2003. [DOI: 10.1016/s1071-9164(03)00564-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
41
|
Horwich T, Lee SJ, Saxon L. Usefulness of QRS prolongation in predicting risk of inducible monomorphic ventricular tachycardiain patients referred forelectrophysiologic studies. Am J Cardiol 2003; 92:804-9. [PMID: 14516880 DOI: 10.1016/s0002-9149(03)00887-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
QRS prolongation on surface electrocardiography has been identified as a marker for increased cardiac mortality. A potential mechanism for increased mortality is ventricular tachycardia (VT). This study aimed to evaluate the relation between bundle branch block and sustained monomorphic VT inducibility in patients referred for electrophysiologic studies. We analyzed a cohort of 777 patients (age 63 +/- 18 years, 67% men, left ventricular [LV] ejection fraction [EF] 45% +/- 16, prior myocardial infarction 41%) referred for electrophysiologic studies between 1994 and 2001 who underwent programmed stimulation for VT. Forty-five percent of patients were referred for syncope or a history of VT and/or ventricular fibrillation. Thirty-one percent of patients had prolonged QRS duration (> or =120 ms). Patients with prolonged QRS duration were older, had lower LVEFs, and were more likely to have a history of myocardial infarction. Prolonged QRS was a significant predictor of sustained monomorphic VT inducibility (p <0.0001). On multivariate analysis correcting for age, sex, LVEF, history of myocardial infarction, medications, and QRS conduction delay proved to be independently associated with sustained monomorphic VT inducibility (relative risk 3.290, 95% confidence interval 2.185 to 4.953 for prolonged vs normal QRS duration). Thus, a prolonged QRS duration on surface electrocardiography is a strong, independent predictor of inducible sustained monomorphic VT. Conduction delay may be an important risk factor, providing a substrate for the development of reentrant monomorphic VT, and furthermore suggests a potential mechanism for the increased mortality observed in patients with prolonged QRS.
Collapse
Affiliation(s)
- Tamara Horwich
- Division of Cardiology, University of California-San Francisco, San Francisco, California 90093, USA
| | | | | |
Collapse
|
42
|
Hayes DL, Naccarelli GV, Furman S, Parsonnet V, Reynolds D, Goldschlager N, Gillette P, Maloney JD, Saxon L, Leon A, Daoud E. NASPE training requirements for cardiac implantable electronic devices: selection, implantation, and follow-up. Pacing Clin Electrophysiol 2003; 26:1556-62. [PMID: 12914640 DOI: 10.1046/j.1460-9592.2003.t01-1-00229.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- David L Hayes
- North American Society of Pacing and Electrophysiology, Natick, Massachusetts 01760-2499, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Bass SL, Saxon L, Daly RM, Turner CH, Robling AG, Seeman E, Stuckey S. The effect of mechanical loading on the size and shape of bone in pre-, peri-, and postpubertal girls: a study in tennis players. J Bone Miner Res 2002; 17:2274-80. [PMID: 12469922 DOI: 10.1359/jbmr.2002.17.12.2274] [Citation(s) in RCA: 289] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Exercise during growth results in biologically important increases in bone mineral content (BMC). The aim of this study was to determine whether the effects of loading were site specific and depended on the maturational stage of the region. BMC and humeral dimensions were determined using DXA and magnetic resonance imaging (MRI) of the loaded and nonloaded arms in 47 competitive female tennis players aged 8-17 years. Periosteal (external) cross-sectional area (CSA), cortical area, medullary area, and the polar second moments of area (I(P), mm4) were calculated at the mid and distal sites in the loaded and nonloaded arms. BMC and I(P) of the humerus were 11-14% greater in the loaded arm than in the nonloaded arm in prepubertal players and did not increase further in peri- or postpubertal players despite longer duration of loading (both, p < 0.01). The higher BMC was the result of a 7-11% greater cortical area in the prepubertal players due to greater periosteal than medullary expansion at the midhumerus and a greater periosteal expansion alone at the distal humerus. Loading late in puberty resulted in medullary contraction. Growth and the effects of loading are region and surface specific, with periosteal apposition before puberty accounting for the increase in the bone's resistance to torsion and endocortical contraction contributing late in puberty conferring little increase in resistance to torsion. Increasing the bone's resistance to torsion is achieved by modifying bone shape and mass, not necessarily bone density.
Collapse
Affiliation(s)
- S L Bass
- School of Health Sciences, Deakin University, Melbourne, Australia
| | | | | | | | | | | | | |
Collapse
|
44
|
Farah HH, Lee SJ, Viloria E, De Marco T, Saxon L, Foster E. Chronic resynchronization therapy does not alter left ventricular geometry. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)80624-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
45
|
Saxon L, Hiltunen AJ, Hjemdahl P, Borg S. Gender-related differences in response to placebo in benzodiazepine withdrawal: a single-blind pilot study. Psychopharmacology (Berl) 2001; 153:231-7. [PMID: 11205424 DOI: 10.1007/s002130000574] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
RATIONALE Benzodiazepines have dependency-producing properties, and the majority of patients who are prescribed benzodiazepines and are treated for benzodiazepine dependency are women. Inability to cope with withdrawal symptoms may lead to continued consumption of benzodiazepines, often with the development of tolerance and dose escalation as a consequence. OBJECTIVE In the present study we analyzed gender-related differences in reactions to placebo injections in a placebo-controlled study of the effects of the benzodiazepine antagonist flumazenil among patients previously treated for benzodiazepine dependency and healthy controls. METHODS Ten patients and ten controls (five males and five females in each group) received two placebo injections (separated by 15 min) on two separate occasions (1-13 weeks apart). The patients had been benzodiazepine free for 47 (4-266) weeks on the first occasion. Subjective ratings of symptoms, thought to be important during/after withdrawal of benzodiazepines, were made before and after each injection, as well as registrations of blood pressure and heart rate. RESULTS An overall difference existed between previously benzodiazepine-dependent subjects and healthy controls, with patients scoring higher on negative and somatic aggregates and lower on a positive aggregate. A four-way interaction (group x gender x occasion x time) was found for negative and somatic aggregates, which could mainly be explained by the reactions of female patients. Thus, females had the highest base-line ratings and were the only group that showed a significant reduction in symptom ratings after placebo injections on the first occasion. Gender differences were also found for systolic and diastolic blood pressure. There was no significant response to placebo among male patients or for controls (males or females) for ratings of any variable. CONCLUSIONS The results suggest that there might be gender-specific differences in reactions to placebo injections, with female patients being more affected. Arguments for and against explanatory factors such as expectation, provider factors, habituation, regression toward the mean, and reduction of anxiety are presented.
Collapse
Affiliation(s)
- L Saxon
- Department of Clinical Neuroscience, Karolinska Institute, Magnus Huss Clinic, Karolinska Hospital, Stockholm, Sweden.
| | | | | | | |
Collapse
|
46
|
Weinryb RM, Busch M, Gustavsson JP, Saxon L, Skarbrandt E. Reliability of the Karolinska Psychodynamic Profile (KAPP) among patients with and without psychoactive substance abuse disorders. Psychother Psychosom 2000; 67:10-6. [PMID: 9491435 DOI: 10.1159/000012253] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The Karolinska Psychodynamic Profile (KAPP) is a rating instrument, based on psychoanalytic theory, that assesses different aspects of character from clinical interviews. The aim of the present study was to examine interrater reliability of the KAPP in a sample of patients with and without psychoactive substance abuse disorders, using interviewers and a reliability judge who had not been trained by the developers of the instrument. METHODS The sample comprised 47 consecutive patients with and without psychoactive substance abuse disorders, who were referred to an outpatient psychotherapy unit specializing in the treatment of substance abuse and dependence. The two interviewers and the reliability judge had not been trained by the developers of the KAPP, and they worked outside the setting where it was constructed. RESULTS The intraclass correlations were satisfactory for the total sample (mean 0.84, median 0.89, range 0.62-0.95), as well as for various sub-samples, such as males and females, and patients with and without substance abuse disorders. CONCLUSIONS The results show that interviewers and a reliability judge who had not been trained by the developers of the KAPP can attain high interrater reliability in a sample of patients with substance abuse disorders. Some recommendations for conducting KAPP interviews are given.
Collapse
Affiliation(s)
- R M Weinryb
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | | | |
Collapse
|
47
|
Hiltunen AJ, Saxon L, Skagerberg S, Borg S. Acute tolerance during intravenous infusion of alcohol: comparison of performance during ascending and steady state concentrations--a pilot study. Alcohol 2000; 22:69-74. [PMID: 11113620 DOI: 10.1016/s0741-8329(00)00107-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although acute tolerance (AT) to alcohol has been demonstrated in many single-dose studies, the existence of AT at steady state concentrations of alcohol has been questioned. In the present study, six subjects were examined as (1) 7.5% alcohol or (2) placebo was administered intravenously (IV). The order of the infusions was randomized. The alcohol infusions were designed to result in similar blood alcohol concentrations at 20, 60, and 140 min (approximately 0. 7 per thousand). At 20 min, the concentrations were rising; the steady state (+/-0.10 per thousand) was reached after 60 min and continued until 140 min. Three reaction time (RT) tests from the automated psychological test system were used (simple RT, two-choice RT, and two-choice RT with auditory inhibition). When the performance of the subjects was compared at rising and steady-state concentrations of alcohol, AT was shown for the most complex task requiring parallel processing, i.e., RT with failed inhibition, test. However, at steady state (i.e., 60 vs. 140 min), AT was not found for any of the tests. Further, the analysis showed that the test results of different individuals were related to their estimated normal alcohol consumption and that these differences presumably influenced the test results in accordance with our earlier findings.
Collapse
Affiliation(s)
- A J Hiltunen
- Department of Clinical Neuroscience, Section of Psychiatry, Karolinska Institute, S-171 77, Stockholm, Sweden.
| | | | | | | |
Collapse
|
48
|
Lozano I, Bocchiardo M, Achtelik M, Gaita F, Trappe HJ, Saxon L, Higgins S, Yong P. Impact of biventricular pacing on mortality in a randomized crossover study of patients with heart failure and ventricular arrhythmias. Eur J Heart Fail 2000. [DOI: 10.1016/s1388-9842(00)80247-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Affiliation(s)
| | | | | | | | | | - Leslie Saxon
- For the VENTAK CHF/CONTAK CD Investigators and Guidant Corporation; St. Paul United States
| | - Steven Higgins
- For the VENTAK CHF/CONTAK CD Investigators and Guidant Corporation; St. Paul United States
| | | |
Collapse
|
49
|
Saxon L, Bass S, Daly R. Heterogeneity in the osteotrophic response to exercise during differenct stages of puberty. J Sci Med Sport 1999. [DOI: 10.1016/s1440-2440(99)80049-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
50
|
Saxon L, Bass S, Daly R. Heterogeneity in the osteotrophic response to exercise during different stages of puberty. J Sci Med Sport 1999. [DOI: 10.1016/s1440-2440(99)80013-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|