Risk factors for reflex syncope in the British Army

INTRODUCTION

Reflex syncope in the UK Armed Forces is reportedly higher than comparable militaries and civilian populations and is significantly more common in soldiers who take part in State Ceremonial and Public Duties (SCPD) compared with other British Army service personnel (SP). This study aimed to investigate individual susceptibility factors for syncope in soldiers who regularly take part in SCPD.

METHODS

A retrospective cohort study was performed in 200 soldiers who perform SCPD. A questionnaire was undertaken reviewing soldiers' medical history and circumstances of any fainting episodes. A consented review of participants' electronic primary healthcare medical record was also performed. Participants were divided into two groups (syncope, n=80; control, n=120) based on whether they had previously fainted.

RESULTS

In the syncope group orthostasis (61%) and heat (35%) were the most common precipitating factors. The most common interventions used by soldiers were to maintain hydration (59%) and purposeful movements (predominantly 'toe wiggling'; 55%). 30% of participants who had previously fainted did not seek definitive medical attention. A history of migraines/headaches was found to increase the risk of reflex syncope (OR 8.880, 1.214-218.8), while a history of antihistamine prescription (OR 0.07144, 0.003671-0.4236), non-white ethnicity (OR 0.03401, 0.0007419-0.3972) and male sex (OR 0.2640, 0.08891-0.6915) were protective.

CONCLUSION

This is the first study, in the British Army, to describe, categorise and establish potential risk factors for reflex syncope. Orthostatic-mediated reflex syncope is the most common cause in soldiers who regularly perform SCPD and this is further exacerbated by heat exposure. Soldiers do not use evidence-based methods to avoid reflex syncope. These data could be used to target interventions for SP who have previously fainted or to prevent fainting during SCPD.

Measure what matters: considerations for outcome measurement of care coordination for children with neurodevelopmental disabilities and medical complexity

Introduction

Care Coordination (CC) is a significant intervention to enhance family's capacity in caring for children with neurodevelopmental disability and medical complexity (NDD-MC). CC assists with integration of medical and behavioral care and services, partnerships with medical and community-based supports, and access to medical, behavioral, and educational supports and services. Although there is some consensus on the principles that characterize optimal CC for children with NDD-MC, challenges remain in measuring and quantifying the impacts of CC related to these principles. Two key challenges include: (1) identification of measures that capture CC impacts from the medical system, care provider, and family perspectives; and (2) recognition of the important community context outside of a hospital or clinical setting.

Methods

This study used a multilevel model variant of the triangulation mixed methods design to assess the impact of a CC project implemented in Alberta, Canada, on family quality of life, resource use, and care integration at the broader environmental and household levels. At the broader environmental level, we used linked administrative data. At the household level we used quantitative pre-post survey datasets, and aggregate findings from qualitative interviews to measure group-level impacts and an embedded multiple-case design to draw comparisons, capture the nuances of children with NDD-MC and their families, and expand on factors driving the high variability in outcome measures. Three theoretical propositions formed the basis of the analytical strategy for our case study evidence to explore factors affecting the high variability in outcome measures.

Discussion

This study expanded on the factors used to measure the outcomes of CC and adds to our understanding of how CC as an intervention impacts resource use, quality of life, and care integration of children with NDD-MC and their families. Given the heterogeneous nature of this population, evaluation studies that account for the variable and multi-level impacts of CC interventions are critical to inform practice, implementation, and policy of CC for children with NDD-MC.

Reflex syncope in the UK Armed Forces

INTRODUCTION

Reflex syncope is the most common subtype of syncope and, despite not being associated with increased mortality, often results in significant morbidity and costly diagnostics. Reflex syncope can be of concern for certain occupational groups and may be exacerbated by some occupations. Reflex syncope in the military is anecdotally common but the extent in the UK Armed Forces (UKAF) is unknown. The aim of this study was to assess the incidence and prevalence of reflex syncope in the UKAF.

METHODS

A retrospective search of the Defence Medical Information Capability Programme using prespecified read-codes was performed at defence primary healthcare centres over the period of 1 January 2019 to 1 January 2020. Data were obtained on 76 103 service personnel (SP) (53% of the UKAF).

RESULTS

The overall syncope case rate for the UKAF was 10.5 per 1000 person-years (p-yrs). In comparing services there was a significantly increased risk of syncope in the British Army (10.7 per 1000 p-yrs) compared with the Royal Air Force (8.6 per 1000 p-yrs) (p=0.0365), SP who served overseas (16.7 per 1000 p-yrs) in comparison with UK medical centres (10.3 per 1000 p-yrs) (p<0.0001), and British Army units that regularly took part in State Ceremonial and Public Duties (15.8 per 1000 p-yrs vs 10.2 per 1000 p-yrs) (p=0.0035). Army training units conferred a significantly reduced risk of syncope (p<0.0001).

CONCLUSIONS

These data are the first to define the incidence and prevalence of syncope in the UKAF. Orthostasis and heat are probable triggers, although recruits are potentially protected. These data offer opportunities to improve the health and well-being of SP, with economic, logistical and reputational benefits for the UKAF. Further research to identify personnel at risk of future syncopal events may allow for targeted use of countermeasures.

Care coordination of children with neurodevelopmental disabilities and medical complexity during the COVID-19 pandemic: Caregiver experiences

BACKGROUND

The COVID-19 pandemic and subsequent public health restrictions created significant challenges for children with neurodevelopmental disabilities with medical complexity and their caregivers including restrictions in care coordination for children and their families. Care coordination enhances families' skills in accessing and coordinating medical, education and disability care across sectors and systems.

OBJECTIVE

This study examined the implications of pandemic restrictions on care coordination from caregiver perspectives. These experiences can inform emergency preparedness planning and recovery strategies.

METHOD

A qualitative descriptive design was utilized to explore and describe the experience of caregivers of children with neurodevelopmental disabilities and medical complexity. Nineteen caregivers were interviewed about their experience with care coordination during the pandemic.

FINDINGS

Caregiver experiences of care coordination during the pandemic highlighted the importance of care coordination during a public health emergency. Two themes emerged: (1) disruptions to care coordination from initial COVID-19 restrictions leading to lack of access to supports and services, increasing level of need, and impacts of disruption for caregivers and children; and (2) adaptation and responsiveness to COVID-19 restrictions by advocating for families and managing uncertainties.

RECOMMENDATIONS

Recommendations include recognition of care coordination as a protective factor, designation as an essential service and sustained or increased funding for care coordination during emergencies. Families should be engaged in identifying care needs during care coordination, including during public health emergencies.

P6542Early Prolonged Ambulatory Cardiac monitoring in Stroke (EPACS): an open-label randomised controlled trial and economic evaluation

Background

Cardioembolism in paroxysmal atrial fibrillation (PAF) is a preventable cause of transient ischaemic attack (TIA) or ischaemic stroke, however, due its transient nature, a short-duration Holter monitor may miss a significant proportion of events.

Methods

We conducted an open-label randomised controlled trial of cardiac monitoring after a TIA or ischaemic stroke comparing a 14-day ECG monitoring patch with short-duration Holter monitoring for the detection of PAF. The primary outcome was the detection of one or more episodes of ECG-documented PAF lasting at least 30 seconds within 90 days in each of the study arms.

A budget impact analysis from the healthcare perspective was performed to assess the theoretical economic implications of the patch-based service versus Holter monitoring. Based on the AF detection rates found in this study, Hospital Episode Statistics data for the incidence of stroke and TIA (October 2016-September 2017) and National Health Service reference costs, the cost-effectiveness of the patch-based service versus Holter monitoring was calculated. The Sentinel Stroke National Audit Programme estimate of £13,452 was used as the mean year one direct medical cost of a stroke.

Results

From February 2016 through February 2017, 43 (76.8%) of the 56 patients assigned to the patch-based monitoring group and 47 (78.3%) of the 60 patients assigned to the short-duration Holter monitoring group had successful monitor placement with 90 days of follow-up (Figure 1). Of the 26 protocol failures between the two groups, 23 (88.5%) were due to patient refusal for outpatient short-duration Holter monitor placement, whilst only 1 (3.8%) was due to unsuccessful patch placement. The rate of detection of PAF at 90 days was 16.3% in the patch-based monitoring group (7 patients) compared to 2.1% in the short-duration Holter monitoring group (1 patient), with an odds ratio of 8.9 (95% CI 1.1–76.0; P=0.026).

Implementation of the patch-based service at our hospital would result in 10.8 more strokes avoided per year compared to current practice with short-duration Holter monitoring. This would equate to a yearly saving in direct medical costs of £57,481, increasing to £106,342 over 5 years. When social care costs are included, incremental savings of £154,716 can be achieved in the first year and £410,449 at 5 years. In addition, an analysis of the potential reduction in outpatient follow-up appointment costs resulted in a further saving of £56,149, giving a total potential saving of £113,630 over the first year with the use of the patch-based service compared to short-duration Holter monitoring, increasing to £162,491 over 5 years.

Figure 1. Study participant flowchart

Conclusions

Early, prolonged, patch-based monitoring after an index stroke or TIA is superior to short-duration Holter monitoring in the detection of PAF and likely cost-effective for preventing recurrent strokes.

Acknowledgement/Funding

Bristol-Myers Squibb-Pfizer alliance (Grant Number CV185-475)

Pathogenese des chronisch-venösen Ulcus cruris

Die physiologische Wundheilung umfasst mehrere Phasen: Entzündungphase mit initialer Blutstillung, Bildung eines Granulationsgewebes, Matrixsynthese und Remodellierung des Ersatzgewebes. In den westlichen Industrienationen ist insbesondere die chronisch-venöse Insuffizienz für Wundheilungsstörungen im Bereich der unteren Extremität verantwortlich. Chronisch-venöse Ulzerationen durchlaufen nicht den physiologischen Wundheilungsablauf, sondern persistieren mit geringer Heilungstendenz in der inflammatorischen Phase.

Das molekulare Verständnis der verzögerten Wundheilung im Rahmen der chronisch-venösen Insuffizienz ist entscheidend für die Entwicklung neuer Therapiestrategien. Aktuell stellen plastisch-rekonstruktive Maßnahmen, die Kompressionstherapie und bei therapierefraktärem Ulcus cruris venosum auch die chirurgische Abtragung des liposklerotischen, periulzerösen Gewebes gängige therapeutische Alternativen dar, um das chronisch aggressive Mikromilieu in ein für die Heilung förderliches umzustellen.

Characterisation of sleep disturbances in postural orthostatic tachycardia syndrome: a polysomnography-based study

BACKGROUND AND AIM

Postural orthostatic tachycardia syndrome (PoTS) has been frequently associated with sleep disturbances but objective sleep data are lacking. In addition, although regional autonomic denervation has been described, less is known about autonomic nervous activity overnight in these patients.

PATIENTS/METHODS

A full polysomnography and heart rate variability were performed on 37 patients diagnosed with PoTS . In addition, a multiple sleep latency test (MSLT) was conducted on a subgroup of patients with excessive daytime sleepiness.

RESULTS

The polysomnographic data did not show major pathological findings except the percentage spent in rapid eye movement (REM) sleep which was slightly reduced at 18.4%. The MSLT did not confirm excessive daytime sleepiness as median mean sleep latency was 14.4 min (11.8-17.5). When comparing patients with and without subjective daytime sleepiness, it was found that the latter had a reduced parasympathetic activation at night as expressed by the average high frequency [6936.5 ms(2) (6028.2-8675.5) vs. 4689.5 (3922.7-7685.2) p < 0.05].

CONCLUSION

Patients with PoTS do not exhibit polysomnographic findings consistent with relevant sleep pathologies nor objective daytime sleepiness. Subjective daytime sleepiness is associated with enhanced activation of the parasympathetic nervous system.

Introduction of new technologies and decision making processes: a framework to adapt a Local Health Technology Decision Support Program for other local settings

PURPOSE

Introducing new health technologies, including medical devices, into a local setting in a safe, effective, and transparent manner is a complex process, involving many disciplines and players within an organization. Decision making should be systematic, consistent, and transparent. It should involve translating and integrating scientific evidence, such as health technology assessment (HTA) reports, with context-sensitive evidence to develop recommendations on whether and under what conditions a new technology will be introduced. However, the development of a program to support such decision making can require considerable time and resources. An alternative is to adapt a preexisting program to the new setting.

MATERIALS AND METHODS

We describe a framework for adapting the Local HTA Decision Support Program, originally developed by the Department of Surgery and Surgical Services (Calgary, AB, Canada), for use by other departments. The framework consists of six steps: 1) development of a program review and adaptation manual, 2) education and readiness assessment of interested departments, 3) evaluation of the program by individual departments, 4) joint evaluation via retreats, 5) synthesis of feedback and program revision, and 6) evaluation of the adaptation process.

RESULTS

Nine departments revised the Local HTA Decision Support Program and expressed strong satisfaction with the adaptation process. Key elements for success were identified.

CONCLUSION

Adaptation of a preexisting program may reduce duplication of effort, save resources, raise the health care providers' awareness of HTA, and foster constructive stakeholder engagement, which enhances the legitimacy of evidence-informed recommendations for introducing new health technologies. We encourage others to use this framework for program adaptation and to report their experiences.

Integrated health systems and integrated knowledge: creating space for putting knowledge into action

The capacity to innovate and share knowledge is not well developed within health systems. In this paper we highlight essential structures, principles and processes for successful implementation of knowledge utilization strategies in complex health systems. We demonstrate essential links between systems that support knowledge utilization and governance, change management, information management and process improvement.

Hyperbaric oxygen, oxidative stress, NO bioavailability and ulcer oxygenation in diabetic patients

BACKGROUND

Hyperbaric oxygen therapy (HBO2) increases tissue oxygenation, thus serving as an adjunct therapy for diabetic wounds. However, in some patients there is insufficient increase in tissue O2.

AIMS

To investigate the pathophysiology of insufficient HBO2 and the possible role of N-acetylcysteine (NAC).

METHODS

Prospective, randomized, cross-over trial included 50 diabetic patients with non-healing ulcers. Each patient received two treatments with 100% oxygen/2ATA. NAC was administered i.v. at one of the two treatments. Basal and post-treatment peri-wound transcutaneous O2 (TcPO2) pressure, malondialdehyde (MDA), total anti-oxidant status (TAOS) and nitric oxide (NO) were assessed. An ulcer oxygenation increase above 200 mmHg was accepted as sufficient.

RESULTS

During HBO2, 17 patients (34%) demonstrated insufficient increase in TcPO2. Concomitantly, their TAOS and NO decreased, while MDA increased. NAC administration attenuated these parameters, thus improving the HBO2 outcome. In those affected by NAC, the cure rate was 75%. By contrast, in 66% of patients with sufficient increase in TcPO2 TAOS was increased and MDA decreased irrespective of NAC administration. The cure rate in this subgroup was 82%.

CONCLUSIONS

Insufficient increase of ulcer oxygenation during HBO2 results from exaggerated oxidative stress and decreased NO bioavailability. NAC administration-induced modulation of both parameters and may improve ulcer oxygenation during HBO2.

Improved quality of life with hyperbaric oxygen therapy in patients with persistent pelvic radiation-induced toxicity

AIMS

We report the results of hyperbaric oxygen therapy (HBOT) used in the treatment of radiation-induced persistent side-effects after the irradiation of pelvic tumours.

MATERIALS AND METHODS

Between January 2001 and December 2005, 13 women (median age 60.3 years) with radiation combined proctitis/cystitis (n=6), longstanding vaginal ulcers and fistulas (n=5) and longstanding skin injuries (n=2) underwent HBOT in a multiplace chamber for a median of 27 sessions (range 16-40). The treatment schedule was HBOT 100% oxygen, at 2 absolute atmospheres, for 90 min, once a day. For radiation-induced toxicity grading we used the National Cancer Institute Common Toxicity Criteria (CTC) grading system, before and after HBOT.

RESULTS

Thirteen patients underwent an adequate number of HBOT sessions. The mean CTC grading score before HBOT was 3.3+/-0.75, whereas the mean CTC grading score after HBOT was 0.3+/-0.63. The scores showed a significant improvement after HBOT (P=0.001; exact Wilcoxon signed-rank test). Rectal bleeding ceased in five of six patients with proctitis and dysuria resolved in six of seven cystitis patients. Macroscopic haematuria stopped in seven of seven patients. Scar complications resolved in two of two patients. None reported HBOT-associated side-effects.

CONCLUSION

HBOT is apparently safe and effective in managing radiation-induced late side-effects, such as soft tissue necrosis (skin and vagina), cystitis, proctitis and fistulas.

Hyperbaric oxygen therapy for nonhealing vasculitic ulcers

BACKGROUND

Cutaneous nonhealing ulceration is a threatening manifestation of vasculitis. Hyperbaric oxygen (HBO), frequently used as adjuvant therapy for patients with ischaemic ulcers, exerts additional beneficial effects on the vascular inflammatory response.

AIM

To evaluate the effect of HBO on vasculitis-induced nonhealing skin ulcers.

METHODS

The study population comprised 35 patients aged >or= 18 years with severe, nonhealing, vasculitis-induced ulcers that had not improved following immunosuppressive therapy. Baseline ulcer tissue oxygenation was evaluated at room air concentration (21% O2), at 1 atmosphere absolute (ATA) breathing 100% O2, and at 2 ATA breathing 100% O2. The baseline treatment protocol consisted of a 4-week course of 100% O2 for 90 min at 2 ATA, five times/week.

RESULTS

The mean baseline ulcer tissue oxygenation (3.1 +/- 2.4 kPa at room air concentration), was significantly increased to 13.9 +/- 11.9 kPa at 1 ATA breathing 100% O2 (P < 0.001), and subsequently increased further to 59.1 +/- 29.8 kPa at 2 ATA breathing 100% O2 (P < 0.001). At the end of the hyperbaric therapy, 28 patients (80%) demonstrated complete healing, 4 (11.4%) had partial healing and 3 (8.6%) had no improvement. None of the patients had any side-effects related to the HBO therapy.

CONCLUSION

HBO therapy may serve as an effective safe treatment for patients with vasculitis having nonhealing skin ulcers. Further studies are needed to evaluate its role as primary therapy for this group of patients.

The efficacy of hyperbaric oxygen therapy (HBOT) in the treatment of pelvic radiation-induced late side effects

18576

Background: The treatment of pelvic malignancies (uterine, cervix, rectum, etc) often include radiation. Radiation-induced late side effects (longer than 3 months) are developed in 5–10% of those patients. We wanted to investigate the efficacy of hyperbaric oxygen therapy (HBOT) in the management of those patients. Methods: Thirteen women were evaluated. The primary cancer sources were: cervix (7), vagina (2), uterus (2), rectum (1) and bladder (1). All patients were treated with a full pelvic dose of radiotherapy. Eight patients also underwent post-radiation surgery (4 post-hysterectomy, 1 post-colectomy, 1 post-vaginectomy, 1 post-cystectomy and 1 post-exanteration). Eleven patients suffered from pelvic pain, 7 from chronic cystitis (including 2 with vesico-vaginal fistulas), 7 had chronic proctitis (including 2 with recto-vaginal fistulas), 3 had long-standing vaginal ulcers, and one presented with a long-standing open skin wound following surgery. All patients underwent imaging studies and biopsies to rule out active malignant disease, and all received HBOT 100% oxygen, at 2 absolute atmospheres, for 90 minutes (2ATA 90 min). Results: The mean patient age was 61 years (range 32–88). The mean time between completion of radiation therapy and onset of symptoms was 32 months (range 4–60). The patients received an average of 27 HBOTs (range 16–40). Twelve patients reported improvement in pelvic pain, bladder and bowel symptoms and decrease in vaginal discharge. One patient developed lung metastasis and another developed pelvic recurrence. No patient reported side effects associated with HBOT. Conclusion: HBOT appears to be safe and effective in the management of pelvic radiation-induced late side effects, such as soft tissue necrosis (skin and vagina), cystitis, proctitis and fistulas.

No significant financial relationships to disclose.

[Predictors of tibial head transposition in the therapy of varus knee osteoarthritis]

PURPOSE

The aim of this study was to find predictors for the clinical outcome in patients who underwent a high tibial osteotomy (HTO).

METHOD

Between 1984 and 1996 a high tibial valgus osteotomy was performed in 155 patients with genu varum. 133 HTO patients were available for follow-up at an average postoperative time of 9.3 +/- 3.0 years. The degree of osteoarthritis was evaluated by radiological (Kellgren) and arthroscopic scoring systems (Outerbridge). Survival time of HTO was estimated using Kaplan-Meier survivorship analysis.

RESULTS

The survival rate of HTO was 95 % after 5 years and 77 % after 10 years. In the medial compartment of knee joints with a preoperative Outerbridge stage III/IV or Kellgren stage III/IV the survival rate of HTO was significantly lower when compared to stages 0/I/II (p < 0.05). Age, sex, tibial malalignment and severity of osteoarthritis in the lateral compartment had no influence on survival rates. The pre-postoperative comparison of radiologically visible signs of osteoarthritis showed mainly either no (46.5 %) or only small (50.5 %) progression. We found that patients who underwent a HTO had good and very good clinical outcomes.

CONCLUSION

We identified severity of preoperative radiological osteoarthritis and intraoperative chondromalacia as predictors of survival rate.

Real-Time Three-Dimensional Echocardiography

Background— Left ventricular (LV) mechanical dyssynchrony (LVMD) has emerged as a therapeutic target using cardiac resynchronization therapy (CRT) in selected patients with chronic heart failure. Current methods used to evaluate LVMD are technically difficult and do not assess LVMD of the whole LV simultaneously. We developed and validated real-time 3D echocardiography (RT3DE) as a novel method to assess global LVMD.

Methods and Results— Eighty-nine healthy volunteers and 174 unselected patients referred for routine echocardiography underwent 2D echocardiography and RT3DE. RT3DE data sets provided time-volume analysis for global and segmental LV volumes. A systolic dyssynchrony index (SDI) was derived from the dispersion of time to minimum regional volume for all 16 LV segments. Healthy subjects and patients with normal LV systolic function had highly synchronized segmental function (SDI, 3.5±1.8% and 4.5±2.4%; P =0.7). SDI increased with worsening LV systolic function regardless of QRS duration (mild, 5.4±0.83%; moderate, 10.0±2%; severe LV dysfunction, 15.6±1%; P for trend <0.001). We found that 37% of patients with moderate to severe LV systolic dysfunction had significant dyssynchrony with normal QRS durations (SDI, 14.7±1.2%). Twenty-six patients underwent CRT. At long-term follow-up, responders demonstrated reverse remodeling after CRT with a significant reduction in SDI (16.9±1.1% to 6.9±1%; P <0.0001) and end-diastolic volume (196.6±17.3 to 132.1±13.5 mL; P <0.0001) associated with an increase in LV ejection fraction (17±2.2% to 31.6±2.9%; P <0.0001).

Conclusions— RT3DE can quantify global LVMD in patients with and without QRS prolongation. RT3DE represents a novel technique to identify chronic heart failure patients who may otherwise not be considered for CRT.

Predicting sudden death in patients with mild to moderate chronic heart failure

OBJECTIVES

To explore the relation between non-invasive measures of cardiac function and sudden cardiac death, as well as the development and utility of an index integrating these variables to identify patients at increased risk of this mode of death.

DESIGN

UK-HEART (United Kingdom-heart failure evaluation and assessment of risk trial) was a prospective study conducted between December 1993 and April 2000. The study was specifically designed to identify non-invasive markers of death and mode of death among patients with chronic heart failure.

SETTING

8 UK general hospitals.

MAIN OUTCOME MEASURES

Death and mode of death.

RESULTS

553 patients aged a mean (SD) of 63 (10) years, in New York Heart Association functional class 2.3 (0.02), recruited prospectively. After 2365 patient-years' follow up, 201 patients had died (67 suddenly). Predictors of sudden death were greater cardiothoracic ratio, QRS dispersion, QT dispersion corrected for rate (QTc) across leads V1-V6 on the 12 lead ECG, and the presence of non-sustained ventricular tachycardia. The hazard ratio and 95% confidence intervals (CI) of sudden death for a 10% increase in cardiothoracic ratio was 1.43 (95% CI 1.20 to 1.71), for a 10% increase in QRS dispersion 1.11 (95% CI 1.04 to 1.19), for the presence of non-sustained ventricular tachycardia 2.03 (95% CI 1.27 to 3.25), and for a 10% increase in QTc dispersion across leads V1-V6 1.03 (95% CI 1.00 to 1.07) (all p < 0.04). An index derived from these four factors performed well in identifying patients specifically at increased risk of sudden death.

CONCLUSIONS

Results show that an index derived from three widely available non-invasive investigations has the potential to identify ambulant patients with chronic heart failure at increased risk of sudden death. This predictive tool could be used to target more sophisticated investigations or interventions aimed at preventing sudden death.

Pulmonary embolism and the electrocardiogram

A 54-year-old man presented with a short-lived episode of blurred vision followed by collapse while shopping. There were no precipitating causes or preceding symptoms. He remained unconscious for less than 1 minute. He recovered sufficiently to continue shopping but presented to casualty 5 hours later with increasing breathlessness. His past medical history included renal colic and a left leg deep vein thrombosis associated with cellulitis 3 years before. His mother had suffered from premature ischaemic heart disease and had died from a pulmonary embolus 25 years before. He took no medication, drank little alcohol but smoked 25 cigarettes per day.