Can we quantify ischaemia during Dobutamine stress echocardiography in clinical practice?

Dobutamine stress echocardiography (DSE) is an accurate non-invasive technique for detecting coronary artery disease and is a test which has significant prognostic value in clinical practice, both in detecting viability and in risk stratification. However, the current clinical implementation of the technique is based solely on the visual detection of ischaemia-induced radial wall motion abnormalities. As such, this approach relies strongly on operator experience and does not attempt to define the distal ischaemic substrate. Reported sensitivities and specificities of DSE for the detection of CAD range between 80% and 85% when performed by experts. One of the main limitations of DSE is the subjective nature of visual interpretation. This is due to a combination of lack of uniform diagnostic criteria and the inability of the eye to resolve the complex short-lived abnormal mechanical events induced by ischaemia. These two factors are mainly responsible for the poor inter-institutional agreement which exists. Indeed the correct visual interpretation of stress echo images requires long training and continuing experience. This is reflected in the current ASE guidelines which recommend the interpretation of at least 15 DSE per month to maintain interpretational skills. Such intensive individual exposure is not frequent. To overcome these limitations several new ultrasound techniques, based on high frame rate imaging, have been developed which could