It is generally agreed that 0.1Hz oscillations characterize the basic properties of the autonomic control of functional components of cardiovascular system. Aim. To study the dynamic of 0.1 Hz oscillations synchronization in the heart rhythm and in the vessels of microcirculation under metoprolol intake during three months in patients with old myocardial infarction. Methods. 20 patients with ischemic heart disease who had had myocardial infarction no less then 6 months ago aged 59±12 were involved in the study. Maximal endurable doses of metoprolol (Metocard-Retard and Metocard, Polpharma) were administered to all the probationers. In 14 of them a daily dose was 200mg. In 3 of them a daily dose was 100mg. For the rest it was 50mg. A simultaneous registration of RR-intervals of electrocardiogram and pulsogram from the distal phalanx of a forefinger was carried out in the probationers under tilt test during 10 minutes with the help of multichannel analyzer EEGA-21/26 «Entsefalan-131-03», model 3 produced by «Medicom-MTD», Russia. Records were made before metoprolol administration and after 3 months of the regular drug intake. 0.1 Hz oscillations were singled out by the band-pass filtering of the signals of RR-chains and a pulsogram. The phase of the compared 0.1 Hz rhythms was estimated. A relative time of synchronization was defined. Clinical status of the patients before and after three months of metoprolol intake was assessed. Results. After three months of intake of maximal endurable doses of metoprolol the number of angina attacks was reduced in average from 24±3 to 10±7 (p<0,01) in the group. The number of intaken tablets of nitroglycerin was also reduced reliably (p<0,01). The increase of the relative time of 0.1 Hz-oscillations synchronization in the heart rhythm and in the vessels of microcirculation under three months of Metocard intake was revealed in 7 patients in the supine posture (by 13.4±8%) and in 10 patients in the standing posture (by 16.1±10%). In the other patients the relative time of synchronization decreased by 19.9±6.7% in the supine posture and by 17.3±7.1 in the standing one. Reliable distinctions in the dynamic of the relative time of synchronization depending on the daily dose of Metocard were not revealed. Conclusion. Using of metoprolol raises the relative time of synchronization of the 0.1 Hz rhythms of cardiovascular system in ~35% of patients in the supine posture and in ~50% in the standing one. It reflects a recovery of the autonomic control and functional relations between the heart rhythm and peripheral circulation in ischemic heart disease patients with old myocardial infarction. The decrease of the relative time of synchronization in a part of the patients shows that in these patients, probably, pathological factors take place and their correction is impossible with the help of beta-blockers only. The study confirms a pronounced antianginal effect produced by metoprolol (Metocard, Metocard-Retard) in patients with old myocardial infarction.
Abstract book of International Congress “Hypertension – from Korotkov to present days”, September 15-17, 2005, Saint-Petersburg, Russia: p 42