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Heart Online First, published on August 19, 2016 as 10.1136/heartjnl-2015-308165 Education in Heart
NON-INVASIVE IMAGING
Setting up a stress echo service: best practice Mathivathana Indrajith, Madalina Garbi, Mark J Monaghan Cardiac Non-Invasive Diagnostics Department, King’s College Hospital NHS Foundation Trust, London, UK Correspondence to Professor Mark J Monaghan, King’s College Hospital NHS Foundation Trust, London, SE5 9RS, UK;
[email protected]
To cite: Indrajith M, Garbi M, Monaghan MJ. Heart Published Online First: [please include Day Month Year] doi:10.1136/heartjnl2015-308165
INTRODUCTION Stress echocardiography (SE) is well established in the assessment of ischaemic heart disease (IHD),1 2 and is used to detect ischaemia due both to epicardial coronary disease and microvascular disease. Furthermore, SE has an evolving role in the assessment of non-IHDs such as cardiomyopathies, valvular heart disease, pulmonary hypertension, heart transplant, congenital heart disease and athlete’s heart.3 To rise up to the challenge of assessing more than only regional wall motion abnormalities (RWMAs), all echocardiographic techniques, both old and new, are currently used in SE (M-mode, two-dimensional (2D), pulsed, continuous and colour Doppler, lung ultrasound, 3D echo, 2D speckle tracking and myocardial contrast echo). The SE protocol is adapted according to the indication and for each particular case.3 There is a wealth of evidence regarding the diagnostic value of SE in IHD and in support of the evolving indications.1–9 Furthermore, there are guidelines, recommendations and appropriateness criteria regarding stress echo clinical indications and the procedure itself.2 4 5 6 8 However, there is limited literature to consult when developing a stress echo service; therefore, we compiled this guide in order to fill in this literature gap.6 When developing a new service, we have to take into consideration demand, capacity, competing techniques, commissioning, local policy for accepted indications, contraindications, and management of complications, types of stress echo to be performed, required space, equipment, consumables and staffing, reporting, audit and potential research. The demand depends on the population covered, the guidelines followed, the agreed referral pathways, the agreed accepted indications and the coexistence of services providing an alternative functional test. The capacity is influenced by the available space, equipment and trained staff. The latter issue is an important limiting factor, especially in the UK. Consequently, a smaller service, generating a lower income, will have less ability to maintain a stable capacity over time when compared with a bigger service with a large number of trained employees. Predicted demand and capacity needs will have to be estimated and will represent the base of the business case. Commissioning depends on local rules and regulations and it obviously has to be agreed before commencing the service, in order to ensure sustainability. However, the cost-effectiveness, ease of availability and lack of radiation of stress echo, when compared with other functional tests, have resulted in a significant growth in the technique.2 4 10
Learning objectives ▸ Understanding the process of stress echo service development and the influencing factors. ▸ Learning the requirements of a stress echo service. ▸ Acknowledging the recommendations and guidelines underpinning a stress echo service.
The local policy will be developed based on the expertise of the clinical lead, the expected demand, the range of indications agreed to be covered, the hospital settings, and the availability of coronary angiography and revascularisation onsite when necessary. Specifications regarding the characteristics of the necessary space (outlined below) are likely to be defined by relevant professional bodies; for example the British Society of Echocardiography (BSE) and European Association of Cardiovascular imaging (EACVI) require certain specifications in order to award accreditation.5 6 Table 1 presents room specification, stress echo service equipment and consumable requirements, which are detailed later within the text. An appropriately trained cardiologist should run the test. In the case of pharmacological stress echo, the presence of an adequately trained nurse is desirable.6 The scanning can be performed by the cardiologist or by a physiologist. All staff involved in SE should have up-to-date training in basic life support and advanced life support (ALS). For some clinical indications, depending on local policy and availability of appropriate training and expertise, the test can be physiologist-delivered or it can be delivered by senior cardiology imaging trainees with sufficient experience.11
STRESS ECHO CLINICAL INDICATIONS Ischaemic heart disease (coronary artery disease) Several non-invasive modalities with reasonable diagnostic power as well as risk stratification of patients are used in the assessment and management of coronary artery disease (CAD).12 The choice of modality relies upon the local expertise and availability as well as upon the clinical indication for the test. Both exercise and pharmacological SE can be used in the assessment of IHD with equal diagnostic yield as other non-invasive functional imaging modalities (table 2). Since introduction in the 1980s, SE has evolved to become a cost-effective and safe method for
Indrajith M, et al. Heart 2016;0:1–8. doi:10.1136/heartjnl-2015-308165
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Education in Heart Table 3 The clinical indications for stress echocardiography use in non-ischaemic heart disease
Table 1 Specific requirements for stress echocardiogram service Room specification 2
25 m Ventilation Lighting Adequate privacy Oxygen ports Suction ports
Equipment required Echo machine with contrast and SE settings ECG machine Blood pressure, pulse and oxygen saturation monitor Echo bed with tilting ability and cardiopulmonary resuscitation position Emergency trolley with advanced life support drugs and equipment including defibrillator Contrast agitator/contrast pump Consumables: 1. Intravenous cannulae insertion kit 2. Intravenous giving sets 3. Contrast and contrast giving sets 4. Oxygen nasal cannulae and masks 5. Suction cannulae 6. ECG electrodes 7. Defibrillator pads
Exercise stress echo
Pharmacological stress echo
Treadmill Ergometric supine bicycle
Intravenous infusion pump Stressor drugs used: A. Dobutamine B. Atropine C. Dipyridamole D. Adenosine
VHD
A. Asymptomatic severe VHD B. Symptomatic non-severe VHD C. Low-flow native or prosthetic valve disease Cardiomyopathies A. Dilated cardiomyopathy for assessment of contractile reserve B. Symptomatic hypertrophic cardiomyopathy with resting LVOT gradient
