Gutron treatment of patients suffering from essential orthostatic hypotony. Part One--Hemodynamic non-invasive investigation.

Essential orthostatic hypotony (EOH) seems to present a rarely occurring and not well recognized syndrome. Group of 20 patients (pts) with EOH were treated with midodrine (Gutron, Gu) 5 mg i.v. Non-invasive hemodynamic variables, such as systolic time intervals and their derivates, based on polycardiographic recordings, were analysed. Heart rate and blood pressure measurements during orthostatic test were measured before and after Gu administration. The results of the orthostatic trial were compared to the control group of 20 volunteers. In healthy subjects, up-right position resulted in heart rate (HR) acceleration, diastolic blood pressure (DBP), total peripheral resistance (TPR), double and triple product (DP, TP), contraction coefficient (PEP/LVET) and dicrotic coefficient ('d') elevation, prejection period (PEP), electromechanical delay (QS1) and isovolumic contraction time (ICT) prolongation and lastly stroke volume (SV), cardiac output (CO) and middle rate of left ventricle ejection time (MRLVET) reduction. Patients with EOH showed a reduction of the degree of tilt-induced changes of the parameters. DBP fell down. After Gu these unfavourable changes were corrected to the values nearer the control group levels in three compensatory mechanisms. After Gu application in EOH-pts were seen: 1) favourable translocation of the resting (supine) values, but with the same reactivity to tilt, as before Gu (HR, TPR); 2) positive influences on orthostatic reaction, but inversely without any changes of resting values (PEPI, ICT, PEP/LVET, DP, DBP) and finally 3) favourable translocation of resting values together with inversed orthostatic reaction (SBP, QS2,TP). We stated clinical valuable efficacy of Gu. Gu influenced mainly the initial state of circulatory hemodynamics in resting and also in a lower degree in orthostatic reaction.