[Effect of adrenergic stimuli on electrocardiographic and vectorcardiographic characteristics of ventricular repolarization].

Autonomic effect of various stimuli on haemodynamic variables is usually tested by changes in blood pressure (BP) and/or heart rate (HR). It is known that increased sympathetic drive of ventricles can interfere with repolarization process. This study was focused on reactive changes of maximal spatial T vector (sTmax), R-R and QTc intervals, in relation to BP changes in 79 boys and men, averaged age 17 +/- 2 years, 36 from them were adolescents with elevated BP (high normal or hypertension I according to WHO/ISH 1999) (ZTK), 19 normotensives (NTK), and 24 normotensive sportsmen.

[Relation between anthropometric indicators and electrocardiogram variability].

Aim: To investigate which combination of anthropometrical parameters influence significantly the variability of the magnitude spatial vectors of atrial (sPmax), activation and ventricular (sQRSmax) activation and ventricular depolarization (sTmax). Quantification of these relationships can improve the reliability of criteria for normal values of ECG and VCG characteristics.

Subjects And Methods: The study group consisted of 195 healthy boys and men without signs of cardiac disease, with normal ECG and VCG, aged from 7 to 70 years, (median = 19 years).

Sensitive markers of the repolarization alterations in systemic hypertension.

Introduction: The early phase of essential hypertension has been associated with changes in cardiovascular regulation caused by imbalance in some parts of autonomic nervous system. Autonomic effect of various stimuli on haemodynamic variables is usually tested by changes in blood pressure (BP) and/or heart rate (HR). It is known that increased sympathetic drive of ventricles can interfere with repolarization process.

Modelling developmental changes of human cardiac electric field in early postnatal period.

In early postnatal life, human cardiac electric field undergoes dramatic changes resulting from the adaptation of the heart to new hemodynamic conditions. For the study of the effect of changes in ventricular geometry as well as in spatial orientation of the heart occurring in this period of life, on the resultant heart vectors, our computer model of propagated activation was used. This model allows to change both mentioned characteristics of ventricles so that they reflect the developmental changes in the human heart.

Blood pressure and heart rate response to head-up position in full-term newborns.

The reactions of heart rate (HR), systolic (sBP) and diastolic (dBP) blood pressure were studied in response to passive head-up tilting (successively to +45 degrees and +90 degrees) in a group of 83 full-term, 1- to 7-day-old newborns who were quiet and awake. A significant mean increase of HR was noted for the whole group, from 121 +/- 14 beats/min to 124 +/- 15 beats/min at +45 degrees and to 127 +/- 17 beats/min at +90 degrees, while sBP rose from 65 +/- 9 mmHg to 67 +/- 12 mmHg at +45 degrees and to 70 +/- 13 mmHg at +90 degrees tilts, respectively (5th post-tilt min). A negative correlation (r = -0.

[Effects of postural changes on blood pressure and pulse rate in neonates].

Information about the effect of body position on blood pressure (BP) in neonates is rare and controversial. The aim of the present study was to investigate the type of orthostatic reaction and it s incidence in a group of infants in relation to basal resting values of BP and heart rate (HR). BP and HR were measured in 125 full-term neonates in the supine position and in the 2nd minute after changing the position by lifting on arms to 90 degrees.

[Normal blood pressure values in neonates and physiologic factors in its variability].

Noninvasive examination of blood pressure by ultrasound sphygmomanometry (LUD 802-TESLA) carried out in 150 physiologic neonates provided insight into resting values of systolic and diastolic blood pressure and heart rate in this series of our urban population (mean value on postnatal day 2:64 +/- 10/36 +/- 7 Torr--8.5 +/- 1.3/5 +/- 0.