Phase and amplitude analysis of exercise digital left ventriculograms in patients with coronary disease.

Abstract

Digital subtraction angiography has recently been applied to left ventricular imaging to detect abnormalities of wall motion.'"As in nuclear cardiology, exercise has been used to induce such abnormalities in regions rendered ischaemic by coronary stenoses, and results similar to those of nuclear gated blood pool scanning have been achieved.34When digital subtraction angiography is performed after exercise, however, the problems of motion subtraction artefact become more important, and the image quality can be considerably impaired. This has less effect on nuclear ventriculography, where the combination of the low resolution and lack of image degradation by bone and soft tissue structures enables satisfactory imaging despite considerable cardiac motion.We showed that satisfactory digital images of the left ventricle after exercise can be achieved by the application of an analysis technique that is not dependent on image subtraction, namely phase and amplitude analysis.' This has been widely used in nuclear cardiology67 and may be applied to any imaging technique that acquires data in a digital format. Therefore, we decided to evaluate this techRequests for reprints to Dr J Lyons, East Surrey Hospital, Three Arch Road, Redhill, Surrey RHI 5RH.Accepted for publication 7 March 1989 nique in the assessment of patients with coronary artery disease. Patients and methods PATIENTSWe studied 48 patients who were investigated by coronary angiography for chest pain and suspected coronary artery disease. Eight of these patients were found to have normal coronary arteries or minor coronary disease (no coronary stenosis > 70%) and were used as a "control" group. Of these none had had a myocardial infarction and five were taking antianginal medication (,B blockers in two

Ischemic heart disease and regional left ventricular wall motion: a study comparing radial, centerline and a video intensity based slope technique

“…It is surprising to find this high sensitivity, since they only used a framing rate of 12.5 images/s which is much lower than conventionally used for left ventriculograms. Fifty-five percent of the patients had myocardial infarcts [19]. In this study, 71% of the patients had no history of prior infarction.…”

“…The frame by frame study by Dawson et al [18] is based on a small population (14 patients with coronary artery disease), and therefore may not be reproducible. A recent study by Lyons et al [19] using phase and amplitude of the fundamental harmonic of the temporal Fourier analysis at rest detected abnormalities in 37 of 40 patients with coronary artery disease. The specificity for the technique in this study was mediocre at 62.5%.…”