Vassilev, Y. N.

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Varna Medical University Press: Journals

T H E VECTORCARDIOGRAM IN SOME STATIC TESTS Y. N. Vassilev Functional changes under modified static conditions (orthostatic, clino-static, transitions to them and the like) using vectorcardiographs registra-tion have not been studied hitherto. They are of interest both from physiolo-gical and c l in ical viewpoint, and have a practical bearing on sports medicine also. The reason of vectorcardiography being insufficiently developed is at-tributed to the fact that as yet, it is in the process of research, part icular ly the three-plane system of Akul inchev (1960), employed in our work ( T z . Pav-lov — 1972). Hence, we made it our a im to carry out observations along this line. A number of physiological positions which afford data contributing to the solution of some important circulation problems were made use of. The orthostatic test has been long since applied in sports medicine neuro-vegetative diagnostics, in certain physiological examinations and the l ike ( N . S. Misjuk et a l . — 1974). R . F . Goldstein et a l . (1975) established a dif-ference in the reaction to the test between healthy individuals and subjects wi th cardiovascular diseases. The si t t ing position constitutes a transition state of the test referred to. The latter is of practical interest since this particular position is employed in veloergometry, and therefore data are indispensable for the interpretation of changes taking place during the test ( L . Tomov, I . Tomov — 1975). More-over, the comparative study of V C G in horizontal and sit t ing position may provide additional information about the state of circulation. On elevated lower part of the body (test of lifted lower limbs) the blood flow distribution is altered. The possibilities of the latter differ in healthy subjects and decompensation. Material and Method A series of twenty c l in ica l ly healthy subjects, aged 15—50 years, were studied. We worked wi th apparatus V E K S 4M according to the three-plane system suggested by I . T . Akul in ichev (1960). Examinat ions were conducted under conditions of secured physical and mental rest, in the morning, after horizontal lying-down position for 10—15 minutes. The in i t ia l vectorcardio-gram ( V C G ) was registered prior to each test. The investigations were made at 30-minute intervals in the following order: 1) test wi th lifted lower part of the body at 60°; 2) sitting position test; 3) orthogonal position test. The optimal time of recording was determined on the basis of preliminary elaborations, proceeding from the complex changes in the organism, registered in addition wi th E C G , blood pressure and heart rate. The a im was to record changes directly provoked by the test, prior to the marked interference of com-120 У. N. Vassllev pensatory mechanisms. Table I illustrates the times of test changes' registra­tion considered as the most favourable. T a b l e I T e s t Optimal registration time Lifted lower part of body 8—10 sec. Sitting position 5—10 sec. Orthostatic position 5—10 sec. Blood pressure measurements were made just prior to testing and after the V C G record. The results of the study were verified stat ist ical ly according to G . P i r y o v and T z . Tzanev (1973). Results * . Lif ted lower part of body test. A reduction of the three Q R S loops is reg­istered in the V C G : wi th mean 20.0 per cent for the frontal loop, 33.33 per cent— 'or the sagittal, and 30.77 per cent — for the horizontal one. The changes are essential for the frontal loop ( T j = 47.58, at T t a b l e 5% = 5 3 ) . The changes for the sagittal and horizontal loop are very significant since T d = 37.8 and 38.84, at T t a b l e 1% = 39. Here the blood pressure shows a systolic increase wi th 9.45 mm Hg aver­age which is essential ( T j = 49.12, at T t a b I e = 5% mm = 53), at insignificant fall of diastolic pressure, averaging 5.12 mm for the group. 2. Sit t ing position test. The rightside and anteriorward shift of the electric axis amounts to a few degrees. The area increase of the lccps is characteristic although it is sta­t i s t ica l ly significant for the horizontal loop only ( T j = 50.13, at T t a b l e 5 % = 53> at 18.70 per cent average modification. The listed below changes cccur in the course of testing: 1) a prompt in­crease of loops in the three planes, lasting for 20 seconds average period; 2) it is followed by a reduction in size; 3) wi th in 3 minutes, the loops are augment­ed once again as compared to the starting horizontal position. Hence, i t i s recommended to perform recording at that very instant. The blood pressure shows an increase in systolic pressure, averaging 9.42 mm Hg for the group, i . e. it is insignificant as T j = 51.19, at T t a b l e 5% = 5 3 . 3. Orthostatic test. V C G reveals about 10 per cent leftside, downward and posteriorward shifting. Simultaneously, area reduction takes place as follows: frontal loop — mean 19.25 per cent, sagittal — 28.84 per cent and horizon­tal — 4.75 per cent. The above described changes are essential for the frontal loop (TA = 48.42, a t T t a b I e 5% = 5 3 ) , very significant for the sagittal loop (Tл =37.58, at T t a b l e 1% = 39), and insignificant for the horizontal loop ( T j = 55.14, at T t a b l e 5% =53) . Changes in the loops from a l l three planes are rather marked in the ex­treme horizontal electric position. Systol ic pressure for the whole group displays a mean 13.53 mm fal l , and diastolic one — a rise wi th 16.83 mm, wi th changes being estimated as signif-The Vectorcardiogram in Some Static Tests 121 icant (accordingly T j = 51.35 and 49.60, at T t a b I e 5% = 53). Reverse reac­tions are also possible in isolated cases, most l ike ly due to a neurovegetative type of dystonia. Discussion The vectorcardiogram proves helpful in the dynamic follow-up of changes in the cardiovascular system. Their statistical significance is demonstrated by the present study. Thus we are enabled to prognosticate the changes in some morbid conditions which w i l l be subject to further studies. Along wi th that, during the sitting and lifted lower part of body tests, the blood pressure displays a systolic increase of about 10 mm Hg, accompanied by various V C G changes: by a reduction of loops in the former, and by an increase of lcops in the latter. A t this point the change in the loop magnitude is in opposite sense, whereas the changes in blood pressure are one-way. T h i s may be explained by the different hemodynamic conditions. I n lifted lower part of body, conditions are created for an enhanced return flow, whilst i n si t t ing position a reflux of part of the blood in the distal segments occurs. I n a l l l ikelihood, a variety of reflectory factors interfere. Ye t in the early pe­riod of cardiac insufficiency, derangements in the listed above regularities might be anticipated. I n orthostatic position a reduction of loops from a l l three planes is ob­served, most probably owing to a degree difference from the sitting position, and to the interference of additional reflex mechanisms as we l l . Furthermore this is an indication that the size of V C G loops in the latter case is less affected by blood pressure than by the other factors exerting in­fluence on the heart electric force. I t is a well known fact that some authors ( M . B . Tar takovsk i i — 1964) attribute the changes in the size of V C G loops to the magnitude of cardiac electric forces. Assessment of the above described vectrocardiographic tests proves the vectorcardiogram sensibility in functional changes taking place in the cardio­vascular system. R E F E R E N C E S 1. А к у л и н ч е в, И. Т. Практические вопросы векторкардиоскопии, М., Медгиз, т960. — 2. М и с ю к, Н . С , А . М. Г у р л е н я, В . В . Е в с т и ч н е е в . Основы 1опической диагностики заболеваний нервной системы, изд. Вышэшая школа, Минск, н974. — 3. П а в л о в , Ц. X . Векторкардиография. В кн. Функционална диагностика 4а заболяванията на сърцето и периферното кръвообращение, С., Мед. и физ. , 1972. —' 1 . П и р ь о в, Г., Ц. Ц а н е в . Експериментална психология, С., Наука и изк., 1973. — 5. Т о м о в, Л . , И л . Т о м о в , М. Т о д о р о в а . Велоергометрия-метод, показания и противопоказания. Вътр. бол., 1975, 1, 81 . — 6. Т а р т а к о в с к и й, М. Б . Основы клинической векторкардиографии. Л . , Медицина, 1964. — 7. G o l d , s t e i n , R . F . , G . D . B e i s e r , M . S t a m p f e r , S. E . E p s t e i n . Impairment of Mediated Heart Rate Control in Patients with Cardiac Disfunction, Circulat. Res, 97 36, , 571. 122 Y. N. Vasilev ВЕКТОКАРДИОГРАММА ПРИ НЕКОТОРЫХ СТАТИЧЕСКИХ ТЕСТАХ Й. Н. Василев ^ Р Е З Ю М Е Производят анализ В КГ при измененных статических условиях : при ортостатическом тесте, тесте с приподнятой нижней частью тела и тест си­дячего положения . Д а н ы и одновременные изменения кровяного давления и оптимальные времена д л я регистрации тестов. Устанавливают отсутствие п а р а л л е л и з м а между величиной петли и высотой кровяного давления . Век-торкардиограмма показывает чувствительность к изменяющимся функцио­н а л ь н ы м условиям сердечно-сосудистой системы. 1 

THE VECTORCARDIOGRAM IN SOME STATIC TESTS

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THE VECTORCARDIOGRAM IN SOME STATIC TESTS

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