Significance of a in-effort rise of pulmonary fixation of thallium in coronaries

It was shown that the in-effort rise in the pulmonary fixation of thallium in coronaries is related to the extension of the coronary-pathy, to its extension on myocardial perfusion and to the presence of a LV dysfunction. In this work we intend to study these 3 types of relation on the same patients, divided into 2 groups. The group I, containing 59 patients, supposed indign of coronary-pathy (probability < 5%), were subject to an in-effort test obtained a frequency superior to 85% of FMT. The group II, containing 44 coronary patients, was explored by coronarography, in-effort myocardial tomo-scintigraphy by Tl and in-effort isotopic ventriculography, within a delay exceeding not 9 months. The pulmonary interest region (IRRL) covers the entire right lung; the myocardial IR (IRC) is limited to the wall of LV and appears as 'normally' fixating. The ratio of fixation RL/C is normalized on the surfaces of IR. In the group I, the ratio RL/C occurred as independent of sex, age or the effort level obtained. Also, it appears to be not influenced by the presence of certain risk factors (tobacco, HTA, diabetes) or the intake of drugs (calcic inhibitor, β-). In the group II the RL/C ratio tends to increase with the number of afflicted trunks (mono-trunkular: 0.41 ± 0.1; tri-trunkular: 0.47 ± 0.12), without significant differences. There exists a positive but loose correlation with the extension of anomalies of the myocardial perfusion at rest (r = 0.42, p < 0.01) or in effort (r = 0.39; p < 0.01). A negative relation was observed with the FElv measured at rest (r = -0.37, p < 0.05). The most tight relation was that observed with the in-effort FElv (r = -0.50, p < 0.001). In conclusion, it appears that the rise in the in-effort pulmonary fixation of thallium is especially related with the LV dysfunction and that it can reveal the importance of causal coronary-pathy only indirectly and imperfectly