The stress echo dilemma: time counts, but image quality too

Abstract

Stress echocardiography has become an attractive tool in the hands of the clinical cardiologist helping in the diagnosis and risk stratification of patients with suspected or known coronary artery disease. However, there are some significant limitations to the technique, so that it remains difficult to acquire the data and to analyse the images. Main limitations for stress echo acquisition are: (i) image quality during transthoracic scanning with insufficient visualization of left ventricle (LV) walls; (ii) probe positioning difficulties resulting in inadequate image planes; and (iii) the time-consuming serial acquisition of different image planes which has to be performed in a narrow time window during peak stress while wall motion abnormalities exist. Regarding data analysis, subjectivity of image interpretation still is the major problem, which leads to poor inter-observer agreement and causes a relevant examiner-dependency. All factors together result in a lack of ability to detect regional myocardial ischaemia and in reduced test accuracy. Over the last 15 years numerous attempts have been undertaken to make stress echocardiography easier and less problematic. Some cardiologists use pharmacological approaches (dobutamine plus atropine) instead of physical stress/exercise to improve image quality and increase the available time for peak level image acquisition. Harmonic imaging with and without contrast enhancement of LV cavity has been shown to improve the endocardial delineation … *Corresponding author. Tel: +49 241 8080605; fax: +49 241 8082303. E-mail address : afranke{at}ukaachen.de