This is a practical description of how replacement valves are assessed using echocardiography. Normal transthoracic appearances including normal variants are described. The problem of differentiating normal function, patient–prosthesis mismatch and pathological obstruction in aortic replacement valves with high gradients is discussed. Obstruction and abnormal regurgitation is described for valves in the aortic, mitral and right-sided positions and when to use echocardiography in suspected infective endocarditis. The roles of transoesophageal and stress echocardiography are described and finally when other imaging techniques may be useful.
John B Chambers
Nikhil Ahluwalia, Sanjeev Bhattacharyya, Christopher Munns and John Chambers
Transoesophageal echocardiography (TOE) can be used to expedite DC cardioversion (DCCV) in the absence of adequate anticoagulation. There are no guidelines for the management of sedation or general anaesthetic. We performed a survey of NHS echocardiography departments to determine UK practice. Responses were received from 95 (50%) of 189 centres, and TOE-guided DCCV was performed in 81 centres. The numbers were <10 a year in 41 (50%), 10 – 50 in 31 (38%), 50 – 100 in 8 (10%) and >100 in 4 (5%) centres. Sedation for TOE was a usual practice in 67 (80%) centres but often temporally disconnected from DCCV due to logistical reasons. TOE under general anaesthetic was performed in 35 (43%) centres and as the usual method in 16 (20%). The patient was in the supine position with endotracheal intubation in 20 (57%) of centres, but without any form of airway protection while supine in 5 (14%). There is variability in practice across centres in the UK, in part due to limitations to services in most centres but also because of an absence of UK guidelines. The development of national standards may address this and aid in the development of local business cases to extend services.
Jenna Smith, Sarah Waters, Brian Campbell and John Chambers
Kelly Victor, Michael M Sabetai and John B Chambers
This case report highlights the utility of paravertebral (PV) imaging in the diagnosis of aortic dissection, the evaluation of left ventricular systolic function and drawing the distinction between pleural and pericardial effusions. In this case, less attenuation of the ultrasound beam, reduced lung viscosity due to pleural effusions and less impedance mismatch between media led to images of superior quality and high diagnostic value. This supports the use of paravertebral imaging as an adjunct to conventional echocardiography windows, particularly when conventional transthoracic imaging proves challenging.
PV images provide superior resolution when interrogating the descending aorta and thus can reveal incidental findings such as aortic dissection.
PV imaging provides clearer delineation between pericardial and pleural effusions.
Additional information may be obtained from the PV window in relation to left ventricular systolic function particularly in the setting of suboptimal transthoracic image quality.
Keith Pearce and John Chambers
John B Chambers, Denise Parkin, James Roxburgh, Vinayak Bapat and Christopher Young
To compare the classical and simplified form of the continuity equation in small Trifecta valves.
This is a retrospective analysis of post-operative echocardiograms performed for clinical reasons after implantation of Trifecta bioprosthetic valves.
There were 60 patients aged 74 (range 38–89) years. For the valves of size 19, 21 and 23mm, the mean gradient was 11.3, 10.7 and 9.7mmHg, respectively. The effective orifice areas by the classical form of the continuity equation were 1.4, 1.7 and 1.9cm2, respectively. There was a good correlation between the two forms of the continuity equation, but they were significantly different using a t-test (P<0.00001). Results using the classical form were a mean 0.11 (s.d. 0.18)cm2 larger than those using the simple formula.
Haemodynamic function of the Trifecta valve in the small aortic root is good. There are significant differences between the classical and simplified forms of the continuity equation.
Nicola Smith, Richard Steeds, Navroz Masani, Julie Sandoval, Gill Wharton, Jane Allen, John Chambers, Richard Jones, Guy Lloyd, Bushra Rana, Kevin O'Gallagher, Richard Wheeler and Vishal Sharma
Hypertrophic cardiomyopathy (HCM) is a relatively common inherited cardiac condition with a prevalence of approximately one in 500. It results in otherwise unexplained hypertrophy of the myocardium and predisposes the patient to a variety of disease-related complications including sudden cardiac death. Echocardiography is of vital importance in the diagnosis, assessment and follow-up of patients with known or suspected HCM. The British Society of Echocardiography (BSE) has previously published a minimum dataset for transthoracic echocardiography, providing the core parameters necessary when performing a standard echocardiographic study. However, for patients with known or suspected HCM, additional views and measurements are necessary. These additional views allow more subtle abnormalities to be detected or may provide important information in order to identify patients with an adverse prognosis. The aim of this Guideline is to outline the additional images and measurements that should be obtained when performing a study on a patient with known or suspected HCM.
Richard Wheeler, Richard Steeds, Bushra Rana, Gill Wharton, Nicola Smith, Jane Allen, John Chambers, Richard Jones, Guy Lloyd, Kevin O'Gallagher and Vishal Sharma
A systematic approach to transoesophageal echocardiography (TOE) is essential to ensure that no pathology is missed during a study. In addition, a standardised approach facilitates the education and training of operators and is helpful when reviewing studies performed in other departments or by different operators. This document produced by the British Society of Echocardiography aims to provide a framework for a standard TOE study. In addition to a minimum dataset, the layout proposes a recommended sequence in which to perform a comprehensive study. It is recommended that this standardised approach is followed when performing TOE in all clinical settings, including intraoperative TOE to ensure important pathology is not missed. Consequently, this document has been prepared with the direct involvement of the Association of Cardiothoracic Anaesthetists (ACTA).