We studied the ability of the ECG to detect pathological changes in isoproterenol-induced remodeling of rat heart. Myocardial hypertrophy in rats was induced by repeated injections of isoproterenol (5 mg/kg s.c. 7 days, Iso5, n=7). Single overdose of isoproterenol (150 mg/kg s.c., Iso150, n=7) evoked myocardial infarction followed with ventricular remodeling. The electrocardiograms were recorded in anesthetized animals (thiopenthal 45 mg/kg i.p.) and myocardial contractile performance was analyzed in isolated hearts perfused according to Langendorff. The hypertrophic hearts were characterized by increased heart and left ventricular (LV) weight as well as by thicker LV free wall and interventricular septum. Mean values of LV contraction did not significantly differ from controls. Longer QT interval, QRS complex, negative Q and S waves, higher R amplitude were typical characteristics for Iso5 rats. Iso150 animals showed tendency to decreased systolic blood pressure and heart frequency. Decrease in the thickness of LV compared to Iso5 as well as impaired LV function were related to the dilated left ventricle. Iso150 ECG showed longer QRS and QT, deepened negativity of S wave and mild decrease of RII compared to Iso5. Voltage criteria showed that Sokolow-Lyon index is a good predictor of left ventricular hypertrophy in isoproterenol-induced cardiac remodeling without systemic hypertension., E. Kráľová, T. Mokráň, J. Murín, T. Stankovičová., and Obsahuje bibliografii a bibliografické odkazy
The aim of our work was to study the opposite polarity of the PQ segment to the P wave body surface potential maps in different groups of patients. We constructed isointegral maps (IIM) in 26 healthy controls (C), 16 hypertensives (HT), 26 patients with arterial hypertension and left ventricular hypertrophy (LVH) and 15 patients with myocardial infarction (MI). We analyzed values and positions of map extrema and compared the polarity of maps using the correlation coefficien t. The IIM P maxima appeared mainly over the precordium, the minima mainly in the right subclavicular area. The highest ma xima were in the MI group, being significantly higher than in the HT and LVH groups. No differences concerning any values of other extrema were significant. The IIM PQ maxima were distributed over the upper half of the chest; the minima mainly over the middle sternum. A statistically significant opposite polarity between the IIM P and IIM PQ was found in 80 % of cases. The opposite polarity of the P wave and the PQ segment was proved in isointegral body surface maps. The extrema occurr ed in areas not examined by the standard chest leads. This has to be considered for diagnostic purposes., K. Kozlíková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy