TC-99M (DUPONT CARDIOLITE) INVESTIGATIONS IN POSTINFARCTION PATIENTS WITH HOLTER-CHECKED SILENT ISCHEMIA

Sixteen middle-aged, normotensive, slightly overweight male patients w ith previous myocaridal infarction were studied during Holter-checked silent myocardial ischaemia. As reference, stress and late 201-T1 scin tigraphy served for comparison with Cardiolite-MIBI silent ischaemic p erfusion scan, both carried out in planar mode. The circumferential pr ofiles differed in 9 cases, on region of interest basis the segment nu mber difference was 10, but the late distribution segment number was n ear to both ischaemic numbers. The quantitative scores were distinctiv e (ratio 133-128/103) indicating the silent ischaemia appeared in the peri-infarct area. The silent ischaemic MIBI and stress 201-T1 ischaem ic score difference was reduced by means of repeated SPECT investigati on. With gated radionuclide ventriculography there was -4.3% differenc e between the left ventricular ejection fractions, measured with first pass MIBI technique during silent ischaemia and afterwards in basal s tate. The impairment of the left ventricular function was reflected on the stroke pattern of our Holter-based radiocyclogram, as well. Takin g the 43.7-48.0 = -4.3% "ischaemic shift" into consideration it was a close correlation (r = 0.90) between the two kinds of ejection fractio n determination. The major rhythm failures (occurring during the 24 h Holter monitoring) decreased to a higher degree the left ventricular e jection fraction than silent ischaemia or silent ischaemia and minor r hythm failure together (38-42-50%).