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2.
Adv Simul (Lond) ; 8(1): 20, 2023 Aug 18.
Article in English | MEDLINE | ID: mdl-37596692

ABSTRACT

BACKGROUND: Applying simulation-based education (SBE) into surgical curricula is challenging and exacerbated by the absence of guidance on implementation processes. Empirical studies evaluating implementation of SBE interventions focus primarily on outcomes. However, understanding the processes involved in organising, planning, and delivering SBE adds knowledge on how best to develop, implement, and sustain surgical SBE. This study used a reform of early years surgical training to explore the implementation of a new SBE programme in Scotland. It aimed to understand the processes that are involved in the relative success (or failure) when implementing surgical SBE interventions. METHODS: This qualitative case study, underpinned by social constructionism, used publicly available documents and the relevant surgical SBE literature to inform the research focus and contextualise data obtained from semi-structured interviews with core surgical trainees (n = 46), consultant surgeons (n = 25), and key leaders with roles in surgical training governance in Scotland (n = 7). Initial data coding and analysis were inductive. Secondary data analysis was then undertaken using Normalisation Process Theory (NPT). NPTs' four constructs (coherence, cognitive participation, collective action, reflexive monitoring) provided an explanatory framework for scrutinising how interventions are implemented, embedded, and integrated into practice, i.e. the "normalisation" process. RESULTS: Distributed leadership (individual SBE initiatives assigned to faculty but overall programme overseen by a single leader) and the quality improvement practise of iterative refinement were identified as key novel processes promoting successful normalisation of the new SBE programme. Other processes widely described in the literature were also identified: stakeholder collaboration, personal contacts/relational processes, effective communication, faculty development, effective leadership, and tight programme management. The study also identified that learners valued SBE activities in group- or team-based social environments over isolated deliberate practice. CONCLUSIONS: SBE is most effective when designed as a comprehensive programme aligned to the curriculum. Programmes incorporating both group-based and isolated SBE activities promote deliberate practice. Distributed leadership amongst faculty attracts wide engagement integral to SBE programme implementation, while iterative programme refinement through regular evaluation and action on feedback encourages integration into practice. The knowledge contributed by critically analysing SBE programme implementation processes can support development of much needed guidance in this area.

3.
Med Educ ; 57(8): 741-752, 2023 08.
Article in English | MEDLINE | ID: mdl-36869257

ABSTRACT

INTRODUCTION: Education and training reforms are typically devised by accreditation bodies and rolled out nationally. This top-down approach is positioned as contextually independent, yet context is highly influential in shaping the impact of change. Given this, it is critical to consider how curriculum reform plays out as it meets local settings. We have therefore used a national-level curriculum reform process of surgical training, Improving Surgical Training (IST), to examine the influence of context in IST implementation across two UK countries. METHODS: Adopting a case study approach, we used document data for contextualisation purposes and semi-structured interviews with key stakeholders across multiple organisations (n = 17, plus four follow-up interviews) as our main source of data. Initial data coding and analysis were inductive. We followed this with a secondary analysis using Engeström's second-generation activity theory nested within an overarching framework of complexity theory to help tease out some key elements of IST development and implementation. RESULTS: The introduction of IST into the surgical training system was historically situated within a landscape of previous reforms. IST's aims collided with existing practices and rules, thus creating tensions. In one country, the systems of IST and surgical training came together to some extent, mostly due to processes of social networks, negotiation and leverage nested in a relatively cohesive setting. These processes were not apparent in the other country, and instead of transformative change, the system contracted. Change was not integrated, and the reform was halted. CONCLUSIONS: Our use of a case study approach and complexity theory deepens understanding of how history, systems and contexts interact to facilitate or inhibit change within one area of medical education. Our study paves the way for further empirical work examining the influence of context in curriculum reform, and thus determining how best to bring about change in practice.


Subject(s)
Curriculum , Education, Medical , Humans , Educational Status
4.
Surgeon ; 21(3): 190-197, 2023 Jun.
Article in English | MEDLINE | ID: mdl-35739002

ABSTRACT

BACKGROUND: The transfer validity of portable laparoscopy simulation is well established. However, attempts to integrate take-home simulation into surgical training have met with inconsistent engagement worldwide, as for example in our 2014-15 study of an Incentivised Laparoscopy Practice programme (ILPv1). Drawing on learning from our subsequent multi-centre study examining barriers and facilitators, we revised the programme for 2018 onwards. We now report on engagement with the 2018-2022 versions of this home-based simulation programme (ILP v2.1-2.3). METHODS: In ILP v2.1-2.3, three consecutive year-groups of new-start Core Surgical Trainees (n = 48, 46 and 53) were loaned portable simulators. The 6-month education programme included induction, technical support, and intermittent feedback. Six tasks were prescribed, with video instruction and charting of metric scores. Video uploads were required and scored by faculty. A pass resulted in an eCertificate, expected at Annual Review (but not mandatory for progression). ILP was set within a wider reform, "Improving Surgical Training". RESULTS: ILP v2.1-2.3 saw pass rates of 94%, 76% and 70% respectively (45/48, 35/46 and 37/53 trainees), compared with only 26% (7/27) in ILP v1, despite now including some trainees not intending careers in laparoscopic specialties. The ILP v2.2 group all reported their engagement with the whole simulation strategy was hampered by the COVID19 pandemic. CONCLUSIONS: Simply providing take-home simulators, no matter how good, is not enough. To achieve trainee engagement, a whole programme is required, with motivated learners, individual and group practice, intermittent feedback, and clear goals and assessments. ILP is a complex intervention, best understood as a "reform within a reform, within a context."


Subject(s)
COVID-19 , Laparoscopy , Simulation Training , Humans , Clinical Competence , COVID-19/epidemiology , Education, Medical, Graduate , Curriculum , Laparoscopy/education , Computer Simulation , Scotland , Simulation Training/methods
5.
Med Educ ; 57(7): 668-678, 2023 07.
Article in English | MEDLINE | ID: mdl-36458943

ABSTRACT

INTRODUCTION: Curricular reform is often proposed as the means to improve medical education and training. However, reform itself may not lead to noticeable change, possibly because the influence of organisational culture on change is given insufficient attention. We used a national reform of early-years surgical training as a natural opportunity to examine the interplay between organisational culture and change in surgical education. Our specific research question was: in what ways did organisational culture influence the implementation of Improving Surgical Training (IST)? METHODS: This is a qualitative study underpinned by social constructivism. Interviews were conducted with core surgical trainees (n = 46) and their supervising consultants (n = 25) across Scotland in 2020-2021. Data coding and analysis were initially inductive. The themes indicated the importance of many cultural factors as barriers or enablers to IST implementation. We therefore carried out a deductive, secondary data analysis using Johnson's (1988) cultural web model to identify and examine the different elements of organisational culture and their impact on IST. RESULTS: The cultural web enabled a detailed understanding of how organisational culture influenced IST implementation as per Johnson's six elements-Rituals and Routines (e.g. departmental rotas), Stories (e.g. historical training norms and culture), Symbols (e.g. feedback mechanisms, visibility and value placed on education), Power Structures (e.g. who has the power in local contexts), Organisational Structures (e.g. relationships and accountability) and the Control System (e.g. consultant job plans and service targets)-and how these interact. However, it did not shed light on the influence of exogenous events on change. CONCLUSION: Our data reveal cultural reasons why this curricular reform met with varying degrees of success across different hospital sites, reinforcing that curricular reform is not simply about putting recommendations into practice. Many different aspects of context must be considered when planning and evaluating change in medical education and training.


Subject(s)
Education, Medical , Organizational Culture , Humans , Qualitative Research , Hospitals , Scotland
6.
Adv Health Sci Educ Theory Pract ; 28(2): 499-518, 2023 05.
Article in English | MEDLINE | ID: mdl-36287293

ABSTRACT

Craft specialties such as surgery endured widespread disruption to postgraduate education and training during the pandemic. Despite the expansive literature on rapid adaptations and innovations, generalisability of these descriptions is limited by scarce use of theory-driven methods. In this research, we explored UK surgical trainees' (n = 46) and consultant surgeons' (trainers, n = 25) perceptions of how learning in clinical environments changed during a time of extreme uncertainty (2020/2021). Our ultimate goal was to identify new ideas that could shape post-pandemic surgical training. We conducted semi-structured virtual interviews with participants from a range of working/training environments across thirteen Health Boards in Scotland. Initial analysis of interview transcripts was inductive. Dynamic capabilities theory (how effectively an organisation uses its resources to respond to environmental changes) and its micro-foundations (sensing, seizing, reconfiguring) were used for subsequent theory-driven analysis. Findings demonstrate that surgical training responded dynamically and adapted to external and internal environmental uncertainty. Sensing threats and opportunities in the clinical environment prompted trainers' institutions to seize new ways of working. Learners gained from reconfigured training opportunities (e.g., splitting operative cases between trainees), pan-surgical working (e.g., broader surgical exposure), redeployment (e.g., to medical specialties), collaborative working (working with new colleagues and in new ways) and supervision (shifting to online supervision). Our data foreground the human resource and structural reconfigurations, and technological innovations that effectively maintained surgical training during the pandemic, albeit in different ways. These adaptations and innovations could provide the foundations for enhancing surgical education and training in the post-pandemic era.


Subject(s)
Learning , Medicine , Humans , Educational Status , Qualitative Research , Pandemics
7.
BMJ Open ; 12(11): e063701, 2022 11 28.
Article in English | MEDLINE | ID: mdl-36442898

ABSTRACT

OBJECTIVE: To evaluate the costs and client outcomes associated with integrating screening and treatment for non-communicable diseases (NCDs) into HIV services in a rural and remote part in southeastern Africa. DESIGN: Prospective cohort study. SETTING: Primary and secondary level health facilities in Neno District, Malawi. PARTICIPANTS: New adult enrollees in Integrated Chronic Care Clinics (IC3) between July 2016 and June 2017. MAIN OUTCOME MEASURES: We quantified the annualised total and per capita economic cost (US$2017) of integrated chronic care, using activity-based costing from a health system perspective. We also measured enrolment, retention and mortality over the same period. Furthermore, we measured clinical outcomes for HIV (viral load), hypertension (controlled blood pressure), diabetes (average blood glucose), asthma (asthma severity) and epilepsy (seizure frequency). RESULTS: The annualised total cost of providing integrated HIV and NCD care was $2 461 901 to provide care to 9471 enrollees, or $260 per capita. This compared with $2 138 907 for standalone HIV services received by 6541 individuals, or $327 per capita. Over the 12-month period, 1970 new clients were enrolled in IC3, with a retention rate of 80%. Among clients with HIV, 81% achieved an undetectable viral load within their first year of enrolment. Significant improvements were observed among clinical outcomes for clients enrolled with hypertension, asthma and epilepsy (p<0.05, in all instances), but not for diabetes (p>0.05). CONCLUSIONS: IC3 is one of the largest examples of fully integrated HIV and NCD care. Integrating screening and treatment for chronic health conditions into Malawi's HIV platform appears to be a financially feasible approach associated with several positive clinical outcomes.


Subject(s)
Asthma , HIV Infections , Hypertension , Noncommunicable Diseases , Adult , Humans , Noncommunicable Diseases/therapy , Cost-Benefit Analysis , Malawi/epidemiology , Prospective Studies , Hypertension/therapy , HIV Infections/therapy
8.
Glob Health Sci Pract ; 10(5)2022 Oct 31.
Article in English | MEDLINE | ID: mdl-36316145

ABSTRACT

INTRODUCTION: Community health worker (CHW) programs have proven effective in improving diabetes control in many locations and settings, but data on feasibility and efficacy are lacking in the Middle East and settings of chronic violence. A Palestinian CHW program, Health for Palestine (H4P), addresses chronic diseases in West Bank refugee camps. Our study assesses the feasibility and effectiveness of the program's diabetes and hypertension interventions. METHODS: Data on home visits, patient retention, and blood pressure were extracted from the CHW records and analyzed. To assess diabetic patient progress, we conducted a retrospective matched cohort study using data obtained from a United Nations (UN) clinical database to analyze the trajectory of hemoglobin A1c (A1c) values. Thirty of the 47 diabetic patients in the H4P CHW program met study inclusion criteria and were each matched with 3 patients from the Bethlehem UN clinic (n=120). We tested for significance using multivariable linear regression with robust standard errors. RESULTS: The average number of home visits per patient per month was 7.3 (standard deviation=4.1), and the patient retention rate was 100% over an average of 11.2 months. For hypertension patients in the CHW program (n=33), mean systolic blood pressure decreased by 7.3 mmHg (95% confidence interval [CI]=1.93, 12.25; P=.009) and mean diastolic blood pressure by 4.3 mmHg (95% CI=0.80, 7.91; P=.018) from March 2018 to November 2019. On average, diabetic patients within the CHW group experienced a 1.4 point greater decline in A1c per year compared to those in the non-CHW group, after adjusting for potential confounders (95% CI=-0.66, -2.1; P<.001). DISCUSSION: The results suggest that CHW accompaniment may be an effective model for improving diabetes and hypertension control in refugee camps experiencing direct violence and extreme adversity. A low exclusion cut-off for A1c (≤6.4%) may underestimate the program's impact.


Subject(s)
Diabetes Mellitus , Hypertension , Humans , Community Health Workers , Glycated Hemoglobin/analysis , Refugee Camps , Cohort Studies , Retrospective Studies , Diabetes Mellitus/epidemiology , Diabetes Mellitus/therapy , Hypertension/therapy
12.
Br J Hosp Med (Lond) ; 81(11): 1-7, 2020 Nov 02.
Article in English | MEDLINE | ID: mdl-33263480

ABSTRACT

AIMS/BACKGROUND: Prophylaxis at discharge is important in mitigating venous thromboembolism events from colorectal cancer and major abdominopelvic surgery, both of which are risk factors for venous thromboembolism. Foundation doctors frequently rotate between departments, and so rely on departmental induction and/or handing down of knowledge to prescribe extended venous thromboembolism prophylaxis upon discharge. METHODS: A retrospective audit of all patients who underwent surgery for colorectal cancer at The County Hospital, Hereford, between 1 August 2018 and 31 August 2019, was undertaken to assess departmental compliance with guidance from the National Institute for Health and Care Excellence. RESULTS: A total of 181 patients underwent elective surgery and 29 patients had emergency surgery. The initial audit revealed a cyclical 4-monthly decline that coincided with foundation doctors' rotations. Six multidisciplinary interventions were implemented. Reaudit demonstrated 100% compliance with prescribing of extended venous thromboembolism prophylaxis at discharge. No venous thromboembolism events 30 days post operation were noted. CONCLUSIONS: A multidisciplinary approach involving educating health professionals about the importance of extended venous thromboembolis prophylaxis in patients who have undergone surgery for colorectal cancer can be effective in improving compliance with prescribing practices at discharge.


Subject(s)
Colorectal Neoplasms , Postoperative Complications , Venous Thromboembolism , Anticoagulants/therapeutic use , Colorectal Neoplasms/surgery , Humans , Patient Discharge , Postoperative Complications/prevention & control , Retrospective Studies , Venous Thromboembolism/etiology , Venous Thromboembolism/prevention & control
13.
BMJ Open ; 10(10): e036836, 2020 10 21.
Article in English | MEDLINE | ID: mdl-33087368

ABSTRACT

OBJECTIVES: Non-communicable diseases (NCDs) account for one-third of disability-adjusted life years in Malawi, and access to care is exceptionally limited. Integrated services with HIV are widely recommended, but few examples exist globally. We report descriptive outcomes from an Integrated Chronic Care Clinic (IC3). DESIGN: This is a retrospective cohort study. SETTING: The study includes an HIV-NCD clinic across 14 primary care facilities in the rural district of Neno, Malawi. PARTICIPANTS: All new patients, including 6233 HIV-NCD diagnoses, enrolled between January 2015 and December 2017 were included. This included 3334 patients with HIV (59.7% women) and 2990 patients with NCD (67.3% women), 10% overall under age 15 years. INTERVENTIONS: Patients were seen at their nearest health centre, with a hospital team visiting routinely to reinforce staffing. Data were collected on paper forms and entered into an electronic medical record. PRIMARY AND SECONDARY OUTCOME MEASURES: Routine clinical measurements are reported at 1-year post-enrolment for patients with more than one visit. One-year retention is reported by diagnosis. RESULTS: NCD diagnoses were 1693 hypertension, 668 asthma, 486 epilepsy, 149 diabetes and 109 severe mental illness. By December 2018, 8.3% of patients with NCD over 15 years were also on HIV treatment. One-year retention was 85% for HIV and 72% for NCDs, with default in 8.4% and 25.5% and deaths in 4.0% and 1.4%, respectively. Clinical outcomes showed statistically significant improvement for hypertension, diabetes, asthma and epilepsy. Of the 1807 (80%) of patients with HIV with viral load results, 85% had undetectable viral load. CONCLUSIONS: The IC3 model, built on an HIV platform, facilitated rapid decentralisation and access to NCD services in rural Malawi. Clinical outcomes and retention in care are favourable, suggesting that integration of chronic disease care at the primary care level poses a way forward for the large dual burden of HIV and chronic NCDs.


Subject(s)
HIV Infections , Noncommunicable Diseases , Adolescent , Female , HIV Infections/drug therapy , Humans , Malawi/epidemiology , Male , Noncommunicable Diseases/epidemiology , Noncommunicable Diseases/therapy , Retrospective Studies , Rural Population
16.
J Inflamm Res ; 11: 77-85, 2018.
Article in English | MEDLINE | ID: mdl-29563826

ABSTRACT

The last two decades have seen the emergence of significant evidence that has altered certain aspects of the management of acute pancreatitis. While most cases of acute pancreatitis are mild, the challenge remains in managing the severe cases and the complications associated with acute pancreatitis. Gallstones are still the most common cause with epidemiological trends indicating a rising incidence. The surgical management of acute gallstone pancreatitis has evolved. In this article, we revisit and review the methods in diagnosing acute pancreatitis. We present the evidence for the supportive management of the condition, and then discuss the management of acute gallstone pancreatitis. Based on the evidence, our local institutional pathways, and clinical experience, we have produced an outline to guide clinicians in the management of acute gallstone pancreatitis.

17.
PLoS One ; 9(9): e92909, 2014.
Article in English | MEDLINE | ID: mdl-25268495

ABSTRACT

BACKGROUND: Clenbuterol (Cl), a ß2 agonist, is associated with enhanced myocardial recovery during left ventricular assist device (LVAD) support, and exerts beneficial remodelling effects during mechanical unloading (MU) in rodent heart failure (HF). However, the specific effects of combined Cl+ß1 blockade during MU are unknown. METHODS AND RESULTS: We studied the chronic effects (4 weeks) of ß2-adrenoceptor (AR) stimulation via Cl (2 mg/kg/day) alone, and in combination with ß1-AR blockade using metoprolol ((Met), 250 mg/kg/day), on whole heart/cell structure, function and excitation-contraction (EC) coupling in failing (induced by left coronary artery (LCA) ligation), and unloaded (induced by heterotopic abdominal heart transplantation (HATx)) failing rat hearts. Combined Cl+Met therapy displayed favourable effects in HF: Met enhanced Cl's improvement in ejection fraction (EF) whilst preventing Cl-induced hypertrophy and tachycardia. During MU combined therapy was less beneficial than either mono-therapy. Met, not Cl, prevented MU-induced myocardial atrophy, with increased atrophy occurring during combined therapy. MU-induced recovery of Ca2+ transient amplitude, speed of Ca2+ release and sarcoplasmic reticulum Ca2+ content was enhanced equally by Cl or Met mono-therapy, but these benefits, together with Cl's enhancement of sarcomeric contraction speed, and MU-induced recovery of Ca2+ spark frequency, disappeared during combined therapy. CONCLUSIONS: Combined Cl+Met therapy shows superior functional effects to mono-therapy in rodent HF, but appears inferior to either mono-therapy in enhancing MU-induced recovery of EC coupling. These results suggest that combined ß2-AR simulation +ß1-AR blockade therapy is likely to be a safe and beneficial therapeutic HF strategy, but is not as effective as mono-therapy in enhancing myocardial recovery during LVAD support.


Subject(s)
Adrenergic beta-1 Receptor Antagonists/pharmacology , Adrenergic beta-2 Receptor Agonists/pharmacology , Clenbuterol/pharmacology , Heart Failure/drug therapy , Heart Transplantation , Metoprolol/pharmacology , Animals , Calcium/metabolism , Drug Therapy, Combination , Excitation Contraction Coupling/drug effects , Heart Failure/metabolism , Heart Failure/pathology , Heart Failure/physiopathology , Heart Rate/drug effects , Male , Myocardium/metabolism , Myocardium/pathology , Rats , Rats, Inbred Lew , Receptors, Adrenergic, beta-1/metabolism , Receptors, Adrenergic, beta-2/metabolism , Stroke Volume/drug effects , Transplantation, Heterotopic , Ventricular Function, Left/drug effects , Ventricular Remodeling/drug effects
18.
Clin Anat ; 27(8): 1275-83, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24615792

ABSTRACT

Urinary incontinence remains an important clinical problem worldwide, having a significant socio-economic, psychological, and medical burden. Maintaining urinary continence and coordinating micturition are complex processes relying on interaction between somatic and visceral elements, moderated by learned behavior. Urinary viscera and pelvic floor must interact with higher centers to ensure a functionally competent system. This article aims to describe the relevant anatomy and neuronal pathways involved in the maintenance of urinary continence and micturition. Review of relevant literature focusing on pelvic floor and urinary sphincters anatomy, and neuroanatomy of urinary continence and micturition. Data obtained from both live and cadaveric human studies are included. The stretch during bladder filling is believed to cause release of urothelial chemical mediators, which in turn activates afferent nerves and myofibroblasts in the muscosal and submucosal layers respectively, thereby relaying sensation of bladder fullness. The internal urethral sphincter is continuous with detrusor muscle, but its arrangement is variable. The external urethral sphincter blends with fibers of levator ani muscle. Executive decisions about micturition in humans rely on a complex mechanism involving communication between several cerebral centers and primitive sacral spinal reflexes. The pudendal nerve is most commonly damaged in females at the level of sacrospinous ligament. We describe the pelvic anatomy and relevant neuroanatomy involved in maintaining urinary continence and during micturition, subsequently highlighting the anatomical basis of urinary incontinence. Comprehensive anatomical understanding is vital for appropriate medical and surgical management of affected patients, and helps guide development of future therapies.


Subject(s)
Hypogastric Plexus/physiopathology , Pelvic Floor/physiopathology , Pudendal Nerve/physiopathology , Urethra/physiopathology , Urinary Bladder/physiopathology , Urinary Incontinence/physiopathology , Urination/physiology , Urothelium/physiopathology , Humans , Hypogastric Plexus/anatomy & histology , Pelvic Floor/anatomy & histology , Pelvic Floor/innervation , Pudendal Nerve/anatomy & histology , Urethra/anatomy & histology , Urethra/innervation , Urinary Bladder/anatomy & histology , Urinary Bladder/innervation , Urothelium/innervation
19.
Cardiovasc Ther ; 31(6): e115-24, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24106913

ABSTRACT

BACKGROUND AND PURPOSE: Specific Na(+) /Ca(2+) exchanger (NCX) inhibition is a potential strategy to correct reduced contractility and depleted sarcoplasmic reticulum (SR) Ca(2+) content in heart failure (HF). SN-6, a benzyloxyphenyl derivative and proposed selective NCX inhibitor, could be used for this purpose. This study aimed to evaluate the effects of SN-6 on contractility and Ca(2+) handling in normal and failing rat cardiomyocytes. EXPERIMENTAL APPROACH: HF was induced in rats by coronary artery ligation. Left ventricular myocytes were isolated and superfused with increasing concentrations of SN-6. KEY RESULTS: Sarcomere shortening, induced by field-stimulation, was reduced in amplitude with increasing concentrations of SN-6 compared with control solution. This effect was greater in failing cells. Kinetics of contractility (time to 90% peak and time to 50% relaxation) were significantly faster. Despite this, intracellular Ca(2+) transients demonstrated no change in the peak amplitude at low concentrations of SN-6, suggesting that SN-6 may affect myofilament sensitivity to Ca(2+) . Ten micro molar SN-6 significantly reduced peak Ca(2+) amplitude by 61.57% and 64.73% in normal and failing cells, respectively. Diastolic Ca(2+) was significantly increased at 1 µM SN-6. SR Ca(2+) content, assessed by rapid application of caffeine, was reduced in failing cells with 1 µM SN-6. Peak ICa , measured by whole-cell patch clamping, was significantly reduced in normal and failing myocytes at 1 µM SN-6. CONCLUSIONS AND IMPLICATIONS: Our data suggest that SN-6 is not a selective inhibitor of NCX and impairs contractility and Ca(2+) handling. Its use, together with similar putative NCX blockers, in correcting the contractile abnormalities of heart failure requires further studies.


Subject(s)
Benzyl Compounds/pharmacology , Calcium/metabolism , Heart Failure/physiopathology , Myocardial Contraction/drug effects , Myocytes, Cardiac/drug effects , Sodium-Calcium Exchanger/antagonists & inhibitors , Thiazolidines/pharmacology , Animals , Myocytes, Cardiac/physiology , Rats , Rats, Sprague-Dawley , Sarcomeres/drug effects
20.
Cardiovasc Res ; 97(2): 230-9, 2013 Feb 01.
Article in English | MEDLINE | ID: mdl-23079200

ABSTRACT

AIMS: Ivabradine (Iva) has shown beneficial structural and functional effects in clinical and experimental heart failure (HF), but its action in combination with mechanical unloading (MU), such as during treatment with left ventricular assist devices (LVAD), is unknown. The aim of this study was to investigate the effects of Iva during MU, in a rodent model of HF. METHODS AND RESULTS: We studied the chronic effects (4 weeks) of Iva (10 mg/kg/day) alone and in combination with MU [induced by heterotopic abdominal heart transplantation (HATx)] on whole-heart and cellular structure, function, and excitation-contraction (E-C) coupling in a rodent (rat) model of HF, 12 weeks post-left coronary artery (LCA) ligation. Effects of Iva were compared with those of ß-blockade using metoprolol [(Met), 250 mg/kg/day]. Iva, but not Met, reversed myocardial fibrosis, alone and in combination with MU. MU-induced restoration of deranged E-C coupling was enhanced by Iva to a greater extent than Met: both Iva and Met enhanced the recovery of the Ca(2+) transient amplitude and the sarcoplasmic reticulum (SR) Ca(2+) content, but Iva alone maintained MU-induced normalization of L-type Ca(2+) current and t-tubule abnormalities. Met prevented MU-induced reduction in the myocardial size (myocardial atrophy); Iva had no effect on this parameter. CONCLUSION: Iva shows beneficial structural and E-C coupling effects during MU: Iva reverses myocardial fibrosis and enhances the restoration of deranged E-C coupling, displaying more beneficial effects than that of Met. These results suggest that Iva may prove effective in enhancing functional recovery in heart failure patients receiving LVAD therapy.


Subject(s)
Benzazepines/pharmacology , Heart Failure/therapy , Heart-Assist Devices , Ventricular Remodeling/drug effects , Animals , Atrophy , Benzazepines/therapeutic use , Calcium/metabolism , Calcium Channels, L-Type/physiology , Excitation Contraction Coupling/drug effects , Fibrosis , Heart Failure/physiopathology , Heart Rate/drug effects , Heart Transplantation , Ivabradine , Metoprolol/pharmacology , Myocardium/pathology , Rats
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