Teamwork in community health committees: a case study in two urban informal settlements.

BACKGROUND: Community health committees (CHCs) are mechanisms for community participation in decision-making and overseeing health services in several low-and middle-income countries (LMICs). There is little research that examines teamwork and internal team relationships between members of these committees in LMICs. We aimed to assess teamwork and factors that affected teamwork of CHCs in an urban slum setting in Nairobi, Kenya. METHODS: Using a qualitative case-study design, we explored teamwork of two CHCs based in two urban informal settlements in Nairobi. We used semi-structured interviews (n = 16) to explore the factors that influenced teamwork and triangulated responses using three group discussions (n = 14). We assessed the interpersonal and contextual factors that influenced teamwork using a framework for assessing teamwork of teams involved in delivering community health services. RESULTS: Committee members perceived the relationships with each other as trusting and respectful. They had regular interaction with each other as friends, neighbors and lay health workers. CHC members looked to the Community Health Assistants (CHAs) as their supervisor and "boss", despite CHAs being CHC members themselves. The lay-community members in both CHCs expressed different goals for the committee. Some viewed the committee as informal savings group and community-based organization, while others viewed the committee as a structure for supervising Community Health Promoters (CHPs). Some members doubled up as both CHPs and CHC members. Complaints of favoritism arose from CHC members who were not CHPs whenever CHC members who were CHPs received stipends after being assigned health promotion tasks in the community. Underlying factors such as influence by elites, power imbalances and capacity strengthening had an influence on teamwork in CHCs. CONCLUSION: In the absence of direction and support from the health system, CHCs morph into groups that prioritize the interests of the members. This redirects the teamwork that would have benefited community health services to other common interests of the team. Teamwork can be harnessed by strengthening the capacity of CHC members, CHAs, and health managers in team building and incorporating content on teamwork in the curriculum for training CHCs.

An unusual case of persisting hypoxia in a patient with a thrombolysed pulmonary embolism.

Exertional breathlessness and hypoxia are common presenting complaints in acute medicine. We describe a case where the patient continued to have persistent hypoxia even after the primary cause (pulmonary embolism) was diagnosed and treated. The hypoxia persisted as an enigma, its cause remaining elusive till diagnosed. Standard first-line investigations would not have reached the underlying diagnosis in this case and, as such, it demonstrates the keen clinical sense and complex investigative strategy required to solve the puzzle.

Atrio-esophageal Fistula Secondary to Atrial Fibrillation Ablation: A Case Report.

BACKGROUND: An atrio-esophageal fistula is an exceedingly rare but devastating complication of atrial fibrillation (AF) ablation procedures. Delays to diagnosis and definitive treatment herald a poor prognosis, with the development of catastrophic neurological injury or death secondary to cerebral air emboli. A high level of suspicion is essential to improve recognition of this rare but devastating condition. CASE REPORT: A 59-year-old man presented to the emergency department with an acute stroke and reduced consciousness. This presentation was preceded by an uncomplicated AF ablation 19 days prior and a subsequent emergency department attendance within a few days of his procedure, where he had presented with a history of new chest pain and reflux symptoms. Imaging revealed intra-cranial and intra-cardiac air, which was attributed to an uncontrolled atrio-esophageal fistula. Treatment options were limited by the patient's clinical instability and the patient was eventually palliated after developing catastrophic brain injury due to extensive cerebral air emboli. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Patients typically first present to the emergency department with new symptoms of either gastroesophageal reflux or chest pain, therefore, early recognition by emergency physicians is vital. Characteristic symptoms alongside a recent history of a cardiac ablation procedure should prompt additional diagnostic imaging to look for evidence of an atrio-esophageal fistula.

Recommended practices to organize and deliver school-based services for children with disabilities: A scoping review.

BACKGROUND: Inclusive educational environments can have a positive effect on the general health and well-being of children with disabilities. However, their level of academic success and participation remains limited. Considering scarce resources and high needs, identifying efficient methods for providing interdisciplinary services is critical. This scoping review, therefore, aims to (a) synthesize current evidence about principles for organizing and delivering interdisciplinary school-based support services for students with disabilities and (b) ascertain useful strategies for implementation of principles in the school setting. METHODS: Scholarly and grey literature in rehabilitation and education were reviewed collaboratively with school-based stakeholders. A search of five databases identified 13,141 references and resulted in 56 relevant articles published from 1998 to 2017. Information (e.g., principles to organize services and strategies for implementation) was extracted, and thematic analysis was used to summarize findings. RESULTS: Within the documents retained, 65% were scientific and 35% were grey. Services primarily targeted students with behavioral issues, followed by those with cognitive and learning disabilities with a focus on improving social-emotional functioning and academic performance. Thematic analysis revealed 10 common principles to guide service organization (e.g., collaborative interventions and support for teachers) and seven implementation strategies (e.g., training and coordination) for employing these principles. CONCLUSIONS: Findings can guide rehabilitation professionals, educators, and policy makers in restructuring well-coordinated collaborative services involving training and capacity-building of school-based service providers. Such knowledge can contribute to the improved provision of care and, consequently, promote children's school participation and inclusion.

The human coronary vasodilatory response to acute mental stress is mediated by neuronal nitric oxide synthase.

Mental stress-induced ischemia approximately doubles the risk of cardiac events in patients with coronary artery disease, yet the mechanisms underlying changes in coronary blood flow in response to mental stress are poorly characterized. Neuronal nitric oxide synthase (nNOS) regulates basal coronary blood flow in healthy humans and mediates mental stress-induced vasodilation in the forearm. However, its possible role in mental stress-induced increases in coronary blood flow is unknown. We studied 11 patients (6 men and 5 women, mean age: 58 ± 14 yr) undergoing elective diagnostic cardiac catheterization and assessed the vasodilator response to mental stress elicited by the Stroop color-word test. Intracoronary substance P (20 pmol/min) and isosorbide dinitrate (1 mg) were used to assess endothelium-dependent and -independent vasodilation, respectively. Coronary blood flow was estimated using intracoronary Doppler recordings and quantitative coronary angiography to measure coronary artery diameter. Mental stress increased coronary flow by 34 ± 7.0% over the preceding baseline during saline infusion (P < 0.01), and this was reduced to 26 ± 7.0% in the presence of the selective nNOS inhibitor S-methyl-l-thiocitrulline (0.625 µmol/min, P < 0.001). Mental stress increased coronary artery diameter by 6.9 ± 3.7% (P = 0.02) and 0.5 ± 2.8% (P = 0.51) in the presence of S-methyl-l-thiocitrulline. The response to substance P did not predict the response to mental stress (r2 = -0.22, P = 0.83). nNOS mediates the human coronary vasodilator response to mental stress, predominantly through actions at the level of coronary resistance vessels.NEW & NOTEWORTHY Acute mental stress induces vasodilation of the coronary microvasculature. Here, we show that this response involves neuronal nitric oxide synthase in the human coronary circulation.Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/nnos-and-coronary-flow-during-mental-stress/.

Blood Pressure in Healthy Humans Is Regulated by Neuronal NO Synthase.

NO is physiologically generated by endothelial and neuronal NO synthase (nNOS) isoforms. Although nNOS was first identified in brain, it is expressed in other tissues, including perivascular nerves, cardiac and skeletal muscle. Increasing experimental evidence suggests that nNOS has important effects on cardiovascular function, but its composite effects on systemic hemodynamics in humans are unknown. We undertook the first human study to assess the physiological effects of systemic nNOS inhibition on basal hemodynamics. Seventeen healthy normotensive men aged 24±4 years received acute intravenous infusions of an nNOS-selective inhibitor, S-methyl-l-thiocitrulline, and placebo on separate occasions. An initial dose-escalation study showed that S-methyl-l-thiocitrulline (0.1-3.0 µmol/kg) induced dose-dependent changes in systemic hemodynamics. The highest dose of S-methyl-l-thiocitrulline (3.0 µmol/kg over 10 minutes) significantly increased systemic vascular resistance (+42±6%) and diastolic blood pressure (67±1 to 77±3 mm Hg) when compared with placebo (both P<0.01). There were significant decreases in heart rate (60±4 to 51±3 bpm; P<0.01) and left ventricular stroke volume (59±6 to 51±6 mL; P<0.01) but ejection fraction was unaltered. S-methyl-l-thiocitrulline had no effect on radial artery flow-mediated dilatation, an index of endothelial NOS activity. These results suggest that nNOS-derived NO has an important role in the physiological regulation of basal systemic vascular resistance and blood pressure in healthy humans.

Remote ischaemic preconditioning suppresses endogenous plasma nitrite during ischaemia-reperfusion: a randomized controlled crossover pilot study.

AIM: The aim of this article is to test the hypothesis that remote ischaemic preconditioning (RIPC) increases circulating endogenous local and systemic plasma (nitrite) during RIPC and ischaemia-reperfusion (IR) as a potential protective mechanism against ischaemia-reperfusion injury (IRI). METHODS: Six healthy male volunteers (mean age 29.5 ± 7.6 years) were randomized in a crossover study to initially receive either RIPC (4 × 5 min cycles) to the left arm, or no RIPC (control), both followed by an ischaemia-reperfusion (IR) sequence (20 min cuff inflation to 200 mmHg, 20 min reperfusion) to the right arm. The volunteers returned at least 7 days later for the alternate intervention. The primary outcome was the effect of RIPC vs. control on local and systemic plasma (nitrite). RESULTS: RIPC did not significantly change plasma (nitrite) in either the left or the right arm during the RIPC sequence. However, compared to control, RIPC decreased plasma (nitrite) during the subsequent IR sequence by ~26% (from 118 ± 9 to 87 ± 5 nmol l-1 ) locally in the left arm (P = 0.008) overall, with an independent effect of -58.70 nmol l-1 (95% confidence intervals -116.1 to -1.33) at 15 min reperfusion, and by ~24% (from 109 ± 9 to 83 ± 7 nmol l-1 ) systemically in the right arm (P = 0.03). CONCLUSIONS: RIPC had no effect on plasma (nitrite) during the RIPC sequence, but instead decreased plasma (nitrite) by ~25% during IR. This would likely counteract the protective mechanisms of RIPC, and contribute to RIPC's lack of efficacy, as observed in recent clinical trials. A combined approach of RIPC with nitrite administration may be required.

Hypoglycemia and Cardiac Arrhythmia; Mechanisms, Evidence Base a nd Current Recommendations.

BACKGROUND: With the use of intensive insulin therapy and insulin secretagogues to optimize glycemic control in diabetes, hypoglycemia continues to present a clinical challenge. Hypoglycemia has been implicated in nocturnal sudden death in type 1 diabetes, and the mechanism underlying this is postulated to be cardiac arrhythmia. OBJECTIVE: This article reviews the evidence surrounding hypoglycemia and cardiac arrhythmia. METHODS: A structured search of the Pubmed bibliographic database was undertaken, and relevant peerreviewed articles on the topic were included in the review. RESULTS: Since the initial description of nocturnal sudden death in type 1 diabetes over twenty years ago, numerous studies have been performed to try and improve our understanding of the effects of hypoglycemia on cardiac rhythm. This includes animal models of diabetes that have permitted valuable insights into the pathophysiology of arrhythmia generation, involving direct effects of hypoglycemia on the cardiac myocyte, effects from sympatho-adrenal activation and a reduced arrhythmia threshold. In humans, the use of tools such as the hypoglycemic clamp or subcutaneous continuous glucose monitoring have helped explore the interaction between hypoglycemia and cardiac rhythm in both controlled and real world settings. Proving a causal link with fatal cardiac arrhythmia is clearly more difficult, as simultaneous monitoring of cardiac rhythm and blood glucose level is rarely performed in this setting. However substantial circumstantial evidence, including that from large randomized clinical trials, exists to support the theoretical risk of arrhythmic death conferred by hypoglycemia. This has reshaped opinion surrounding intensive glucose lowering in patients with diabetes and heart disease, and is reflected in recent international guidelines. CONCLUSION: This article reviews the postulated mechanisms, the extensive evidence base and the current recommendations around hypoglycemia and arrhythmia.

Clinical utility of speckle-tracking echocardiography in cardiac resynchronisation therapy.

Cardiac resynchronisation therapy (CRT) can profoundly improve outcome in selected patients with heart failure; however, response is difficult to predict and can be absent in up to one in three patients. There has been a substantial amount of interest in the echocardiographic assessment of left ventricular dyssynchrony, with the ultimate aim of reliably identifying patients who will respond to CRT. The measurement of myocardial deformation (strain) has conventionally been assessed using tissue Doppler imaging (TDI), which is limited by its angle dependence and ability to measure in a single plane. Two-dimensional speckle-tracking echocardiography is a technique that provides measurements of strain in three planes, by tracking patterns of ultrasound interference ('speckles') in the myocardial wall throughout the cardiac cycle. Since its initial use over 15 years ago, it has emerged as a tool that provides more robust, reproducible and sensitive markers of dyssynchrony than TDI. This article reviews the use of two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of dyssynchrony, including the identification of echocardiographic parameters that may hold predictive potential for the response to CRT. It also reviews the application of these techniques in guiding optimal LV lead placement pre-implant, with promising results in clinical improvement post-CRT.

Physiological Reduction in Left Ventricular Contractile Function in Healthy Postpartum Women: Potential Overlap with Peripartum Cardiomyopathy.

AIMS: Peripartum cardiomyopathy is a potentially life-threatening cause of heart failure, commoner in Afro-Caribbean than Caucasian women. Its diagnosis can be challenging due to physiological changes in cardiac function that also occur in healthy women during the early postpartum period. This study aimed to (i) establish the overlap between normal cardiac physiology in the immediate postpartum period and pathological changes in peripartum cardiomyopathy ii) identify any ethnicity-specific changes in cardiac function and cardiac biomarkers in healthy postpartum women. METHODS AND RESULTS: We conducted a cross-sectional study of 58 healthy postpartum women within 48 hours of delivery and 18 matched non-pregnant controls. Participants underwent cardiac assessment by echocardiography and strain analysis, including 3D echocardiography in 40 postpartum women. Results were compared with 12 retrospectively studied peripartum cardiomyopathy patients. Healthy postpartum women had significantly higher left ventricular volumes and mass, and lower ejection fraction and global longitudinal strain than non-pregnant controls. These parameters were significantly more impaired in peripartum cardiomyopathy patients but with overlapping ranges of values. Healthy postpartum women had higher levels of adrenomedullin, placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt1) compared to controls. The postpartum state, adrenomedullin, sFlt1 and the sFlt1:PlGF ratio were independent predictors of LV remodelling and function in healthy postpartum women. CONCLUSION: Healthy postpartum women demonstrate several echocardiographic indicators of left ventricular remodelling and reduced function, which are associated with altered levels of angiogenic and cardiac biomarkers.

T1-Mapping and Outcome in Nonischemic Cardiomyopathy: All-Cause Mortality and Heart Failure.

OBJECTIVES: The study sought to examine prognostic relevance of T1 mapping parameters (based on a T1 mapping method) in nonischemic dilated cardiomyopathy (NIDCM) and compare them with conventional markers of adverse outcome. BACKGROUND: NIDCM is a recognized cause of poor clinical outcome. NIDCM is characterized by intrinsic myocardial remodeling due to complex pathophysiological processes affecting myocardium diffusely. Lack of accurate and noninvasive characterization of diffuse myocardial disease limits recognition of early cardiomyopathy and effective clinical management in NIDCM. Cardiac magnetic resonance (CMR) supports detection of diffuse myocardial disease by T1 mapping. METHODS: This is a prospective observational multicenter longitudinal study in 637 consecutive patients with dilated NIDCM (mean age 50 years [interquartile range: 37 to 76 years]; 395 males [62%]) undergoing CMR with T1 mapping and late gadolinium enhancement (LGE) at 1.5-T and 3.0-T. The primary endpoint was all-cause mortality. A composite of heart failure (HF) mortality and hospitalization was a secondary endpoint. RESULTS: During a median follow-up period of 22 months (interquartile range: 19 to 25 months), we observed a total of 28 deaths (22 cardiac) and 68 composite HF events. T1 mapping indices (native T1 and extracellular volume fraction), as well as the presence and extent of LGE, were predictive of all-cause mortality and HF endpoint (p < 0.001 for all). In multivariable analyses, native T1 was the sole independent predictor of all-cause and HF composite endpoints (hazard ratio: 1.1; 95% confidence interval: 1.06 to 1.15; hazard ratio: 1.1; 95% confidence interval: 1.05 to 1.1; p < 0.001 for both), followed by the models including the extent of LGE and right ventricular ejection fraction, respectively. CONCLUSIONS: Noninvasive measures of diffuse myocardial disease by T1 mapping are significantly predictive of all-cause mortality and HF events in NIDCM. We provide a basis for a novel algorithm of risk stratification in NIDCM using a complementary assessment of diffuse and regional disease by T1 mapping and LGE, respectively.

T1 Mapping in Discrimination of Hypertrophic Phenotypes: Hypertensive Heart Disease and Hypertrophic Cardiomyopathy: Findings From the International T1 Multicenter Cardiovascular Magnetic Resonance Study.

BACKGROUND: The differential diagnosis of left ventricular (LV) hypertrophy remains challenging in clinical practice, in particular, between hypertrophic cardiomyopathy (HCM) and increased LV wall thickness because of systemic hypertension. Diffuse myocardial disease is a characteristic feature in HCM, and an early manifestation of sarcomere-gene mutations in subexpressed family members (G+P- subjects). This study aimed to investigate whether detecting diffuse myocardial disease by T1 mapping can discriminate between HCM versus hypertensive heart disease as well as to detect genetically driven interstitial changes in the G+P- subjects. METHODS AND RESULTS: Patients with diagnoses of HCM or hypertension (HCM, n=95; hypertension, n=69) and G+P- subjects (n=23) underwent a clinical cardiovascular magnetic resonance protocol (3 tesla) for cardiac volumes, function, and scar imaging. T1 mapping was performed before and >20 minutes after administration of 0.2 mmol/kg of gadobutrol. Native T1 and extracellular volume fraction were significantly higher in HCM compared with patients with hypertension (P<0.0001), including in subgroup comparisons of HCM subjects without evidence of late gadolinium enhancement, as well as of hypertensive patients LV wall thickness of >15 mm (P<0.0001). Compared with controls, native T1 was significantly higher in G+P- subjects (P<0.0001) and 65% of G+P- subjects had a native T1 value >2 SD above the mean of the normal range. Native T1 was an independent discriminator between HCM and hypertension, over and above extracellular volume fraction, LV wall thickness and indexed LV mass. Native T1 was also useful in separating G+P- subjects from controls. CONCLUSIONS: Native T1 may be applied to discriminate between HCM and hypertensive heart disease and detect early changes in G+P- subjects.

Impaired neuronal nitric oxide synthase-mediated vasodilator responses to mental stress in essential hypertension.

Neuronal NO synthase (nNOS) regulates blood flow in resistance vasculature at rest and during mental stress. To investigate whether nNOS signaling is dysfunctional in essential hypertension, forearm blood flow responses to mental stress were examined in 88 subjects: 48 with essential hypertension (42±14 years; blood pressure, 141±17/85±15 mm Hg; mean±SD) and 40 normotensive controls (38±14 years; 117±13/74±9 mm Hg). A subsample of 34 subjects (17 hypertensive) participated in a single blind 2-phase crossover study, in which placebo or sildenafil 50 mg PO was administered before an intrabrachial artery infusion of the selective nNOS inhibitor S-methyl-l-thiocitrulline (SMTC, 0.05, 0.1, and 0.2 µmol/min) at rest and during mental stress. In a further subsample (n=21) with an impaired blood flow response to mental stress, responses were measured in the presence and absence of the α-adrenergic antagonist phentolamine. The blood flow response to mental stress was impaired in hypertensive compared with normotensive subjects (37±7% versus 70±8% increase over baseline; P<0.001). SMTC blunted responses to mental stress in normotensive but not in hypertensive subjects (reduction of 40±11% versus 3.0±14%, respectively, P=0.01, between groups). Sildenafil reduced the blood flow response to stress in normotensive subjects from 89±14% to 43±14% (P<0.03) but had no significant effect in hypertensive subjects. Phentolamine augmented impaired blood flow responses to mental stress from 39±8% to 67±13% (P<0.02). Essential hypertension is associated with impaired mental stress-induced nNOS-mediated vasodilator responses; this may relate to increased sympathetic outflow in hypertension. nNOS dysfunction may impair vascular homeostasis in essential hypertension and contribute to stress-induced cardiovascular events.

"Cold can for a hot case": use of a coronary sinus shocking lead in association with cold can to achieve successful defibrillation.

Attaining an adequate defibrillation threshold is critical in the functioning of an implantable cardioverter-defibrillator. This is achieved in a majority of implants but in those where this does not occur, reprogramming, lead repositioning, and ultimately placement of a subcutaneous array lead may be necessary.

Treatment of inappropriate sinus tachycardia with ivabradine in a patient with postural orthostatic tachycardia syndrome and a dual chamber pacemaker.

We present the case of a 44-year-old woman with postural orthostatic tachycardia syndrome (POTS) and a dual chamber pacemaker. The patient suffered from inappropriate sinus tachycardia that had been resistant to treatment with traditional rate-slowing medications. Ivabradine--the specific sinus node I(f) current inhibitor--was used to successfully lower the heart rate. The patient had no evidence of POTS on repeat autonomic function testing, and there was a corresponding symptomatic benefit. We propose that this class of drugs, the use of which is established as antianginals, should be considered in patients with resistant inappropriate sinus tachycardia.

Extraction of chronic pacemaker and defibrillator leads from the coronary sinus: laser infrequently used but required.

AIMS: Cardiac resynchronization therapy is an accepted treatment for heart failure but it may be necessary to explant these systems along with their leads. The evidence base for coronary sinus (CS) lead extractions is limited. We aimed to evaluate the percutaneous removal of these leads and the utility of laser extraction when necessary. METHODS AND RESULTS: Of 265 patients referred for lead extraction between January 2004 and June 2008, 32 (12.1%) involved CS leads (30 males, mean age 67 years). Mean implantation time was 26.5 +/- 28.7 months (range 1-116 months). Indications for extraction were pocket infection (34.4%), lead malfunction (43.8%), skin erosion (15.6%), and endocarditis (6.2%). Twenty-eight (87.5%) CS leads were removed with manual traction, with laser utilized in four cases (12.5%). No major complications of CS laceration, pericardial effusion, emergency surgery, or death occurred. CONCLUSION: Our experience supports the percutaneous extraction of CS leads as a safe and effective procedure including the utility of laser when necessary.