A comprehensive noninvasive haemodynamic assessment with a single injection of technetium-99M

Summary form only given. In order to identify patients at high risk of subsequent cardiac events after myocardial infarction, 105 patients underwent gated blood pool ventriculography under standard conditions. An automatic program was developed using a mnemonic language and subroutines of a powerful software (F1). Nine-point smoothing and time correction were applied to the raw data and the frames were played in an endless cine display for visual assessment of regional wall motion (RWM). Fourier analysis was used to generate phase and amplitude images. An automatic edge defining algorithm was applied using the second derivative and the local threshold to produce a high-resolution time-activity curve from which the background was subtracted automatically. The analysis was repeated by the same operator and a second operator in 30 cases three months later to assess the reproducibility and repeatability. Patients were followed up for an average period of 19 months. The single most predictive variable of major cardiac events was found to be RWM scores with a sensitivity of 94% and a specificity of 57%