抄録
This study was designed in order to reexamine the changes in the ECG findings among the patients with so-called neurocirculatory asthenia (NCA). Analyses of ECG were done not only with those conditions at rest and/or at the episodes of heart attack, but also with those taken after Master's two step test as well as Mirror Drawing Test (MDT). 50 cases with NCA were picked up according to its characteristic subjective symptoms and compared with 84 control subjects. During mental stress loading by MDT, changes in heart rate, blood pressure, serum FFA levels and urinary excretion levels of catecholamines(CA)were determined simultaneously.MDT revealed some abnormal patterns of ECG such as ST-T changes and /or various arrhythmias, the frequency of which was rather higher than that of exercise test. Of all the 50 cases with NCA, abnormal ECG findings were frequently seen by MDT loading in as many as 56%, while the controls showed only 9.7% abnormalities. According to the ECG findings, our own criteria of abnormal ECG in psychological stress loading were established. An attempt was then made to classify these patients with NCA into two groups, A and B. Group A was designated as cardiac neurosis, where no abnormal ECG finding was obtained. In contrast, group B which we named "latent functional coronary insufficiency" was further divided into three subgroups, B_1 (physical type), B_2 (etmotional type) and B_3 (mixed type).Especially, groups B_2 and B_3 shoewd more hyperresponses of endogenous adrenaline, of blood pressure and of heart rate than group A and controls in MDT. These results suggest that the abnormal ECG findings in these groups are caused by cardiac hyperfunctions due to an easier increase in sympathetic tone after stress loading. Hence, the two groups of A and B may psychophysiologically differ from each other. However, whether or not they have quite a different etiological origin is still obscure. On account of some cases in groups B_2 and B_3 with relatively low response of CA levels in MDT, it seems plausible that these groups havea a closely similar pathogenesis to that of "hyperdynamic beta-adrenergic circulatory state".
