There are three basic procedures used for an assessment of the electrical heart field from the body surface: standard electrocardiography, vectorcardiography, and body surface potential mapping (BSPM). BSPM has two major advantages over both other methods: 1) it allows exploring the entire chest surface, thus providing all the information on the cardiac electric field available at the body surface; 2) it is more sensitive in detecting local electrical events, such as local conduction disturbances or regional heterogeneities of ventricular recovery. Nevertheless the results obtained using BSPM procedure cannot answer all questions about real causality of detected changes of the electrical heart field. We tried therefore to use mathematical model of the electrical field in order to answer these questions. A simple and anatomical forward calculation model was used to test the hypothesis whether the altered position of the heart could explain heterogeneity of repolarization at late stages of pregnancy in humans. The hypothesis was declined. Further findings included: A. Repolarization duration (represented by QT interval) in healthy subjects are distributed regularly and predictably on the body surface carrying no information about local pathology. B. At any systemic analysis of ventricular repolarization, it is vital to consider the regions where any electrode systems record low amplitudes due to methodological, not pathological reasons. C. Anatomical (heterogeneous) model did not yield superior results over simple (homogenous) ones possibly since none reflected the specific torso geometry of individual patients., O. Kittnar, M. Mlček., and Obsahuje bibliografii a bibliografické odkazy
In order to study a possible effect of mini-invasive heart intervention on a response of hypothalamo-pituitary-adrenal stress axis, we analyzed four stress markers (cortisol, cortisone, DHEA and DHEAS) in 25 sows using minimally invasive heart catheterisation as the stress factor. The marker levels were assessed in four periods of the experiment, (1) the baseline level on the day before intervention, (2) after the introduction of anesthesia, (3) after conducting tissue stimulation or ablation, and (4) after the end of the catheterisation. For statistical analyses we used the non-parametric Friedman test for four dependent samples (including all four stages of the operation) or three dependent samples (influence of operation only, baseline level was excluded). Statistically significant differences in both Friedman tests were found for cortisol and for cortisone. Significant differences for DHEA as well as for DHEAS were found for all tested stages but not for the effect of operation itself. We have concluded that cortisol levels are blunted by the influence of anesthesia after its administration, and therefore decrease back to the baseline at the end of the operation. The other markers (cortisone, DHEA and DHEAS) acted as balanced systems against the injurious stress effect., H. Skarlandtová, M. Bičíková, P. Neužil, M. Mlček, V. Hrachovina, T. Svoboda, E. Medová, J. Kudlička, A. Dohnalová, Š. Havránek, H. Kazihnítková, L. Máčová, E. Vařejková, O. Kittnar., and Obsahuje bibliografii
a1_Diabetes mellitus is a risk factor of cardiovascular diseases. ECG of patients with diabetes mellitus type 1 (DM 1) shows tachycardia (block of parasympathetic innervation) and abnormal repolarization (increased QT interval and QT dispersion (QTd)) indicating a risk of ventricular tachycardia and sudden death in young people with DM 1. The aim of the present report was to measure 145 parameters of the heart electric field in 22 patients (14 men, 8 women) with DM 1 without complications (mean age 32.8±11.4 years) and in 22 controls (11 men, 11 women, mean age 30.1±3.4 years). The duration of diabetes was 13.9 ±7.8 years. The parameters were regist ered by the diagnostic system Cardiag 112.2 and statistically evaluated by the Student and Mann-Whitney test. Tachycardia (86.3±2.7 beats.min-1), shortening of both QRS (79.9±1.6 ms) and QT (349.0±5.9 ms) and increased QT dispersion (115±36 ms) were observed in DM 1 when compared with the controls (75.0±2.1 beats. min -1, QRS 89.9±2.7 ms, QT 374.0±4.4 ms, QTd 34.0±12.0 ms, p<0.01). The QTc was 415.2±4.1 ms in DM 1 and 401.4±6.6 ms in controls (NS)., a2_Other significant findings in DM 1 were: higher maximum of depolarization isopotential maps (DIPMmax) in the initial phase of QRS and less positive in the terminal phase, more negative minimum (DIPMmin) during QRS similarly as the minimum in depolarization isointegral maps (DIIMmin) and the minimum in isointegral map of the Q wave (Q-IIMmin), lower maximum in repolarization isopotential maps (RIPMmax) and less negative minimum (RIPMmin), more negative amplitude of Q wave (Q-IPMAM) and more pronounced spread of depolarization (activation time). Our results confirmed a decreased parasympathetic to sympathetic tone ratio (tachycardia, shortening of the activation time) and revealed different depolarization and repolarization patterns in DM 1. The differences in heart electric field parameters measured by the BSPM method in DM 1 and in the controls indicate the importance of ECG examination of diabetic patients type 1 in the prevention of cardiovascular diseases., D. Žďárská, P. Pelíšková, J. Charvát, J. Slavíček, M. Mlček, E. Medová, O. Kittnar., and Obsahuje bibiografii a bibliografické odkazy
ECG body surface mapping (BSM) parameters in patients with diabetes mellitus Type 1 (DM1) are significantly different comparing to healthy non-diabetic subjects. Hypothesis that these changes are more pronounced in DM1 patients with autonomic neuropathy (AN) was tested. The parameters of BSM were registered by diagnostic system Cardiag 112.2 in 54 DM1 patients including 25 with AN and 30 control subjects. AN was diagnosed according to Ewing criteria when two or more Ewing tests were abnormal. In classic 12-lead ECG the heart rate was increased, QRS and QT shortened (p<0.01) and QTC prolonged in DM1 patients. The VCG measurement of QRS-STT angles and spatial QRS-STT angle showed non-significant differences. The absolute values of maximum and minimum in depolarization and repolarization isopotential, isointegral, isoarea maps were significantly different in DM1 patients in comparison with controls (p<0.01). The changes were more pronounced in DM1 patients with AN than in DM patients without AN (p<0.05). The QT duration measured in 82 leads of thorax was significantly shortened in 68 leads of both groups of DM 1 patients (p<0.01) when compared with controls. In 34 of them this shortening was more pronounced in DM1 patients with AN than in DM1 patients without AN (p<0.05). The results showed that the method of ECG BSM is capable to confirm the presence of autonomic neuropathy in diabetic patients., S. Palová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Women with gestational diabetes mellitus (GDM) are at increased risk for cardiovascular diseases (CVD) events compared with women without GDM. The aim of the present study was to evaluate 200 parameters of the heart electric field in 35 women with GDM under optimal glycemic compensation compared to 32 healthy pregnant women. All examinations were performed in the 36th week of gestation. The parameters in ECG body surface mapping (BSM) were registered by the diagnostic system Cardiag 112.2. The absolute values of maximum and minimum in depolarization and repolarization isopotential, isointegral and isoarea maps were not significantly different between the groups. These findings correspond to the result of heart rate variability examination. However BSM revealed the significant prolongation of QRS complex (p=0.05), shortening of ventricular myocardial activation time (ICHVAT) (p=0.01), prolongation of mean QT duration (p=0.01) and increase of QT interval dispersion (p=0.01) in women with GDM. Duration of QRS and ICHVAT significantly correlated with interventricular septum and posterior wall thickness in GDM group, QTd interval correlated significantly with HbA1C level. We conclude that despite of optimal metabolic control several significant abnormalities detected by ECG BSM are still present in patients with GDM., E. Žákovičová, O. Kittnar, J. Slavíček, E. Medová, P. Šváb, J. Charvát., and Obsahuje bibliografii
An increased risk of myocardial ischemic changes was demonstrated in patients suffering from panic disorder (PD). Using classical ECG methods, this risk cannot be evaluated in most patients. We measured the vectocardiogram (VCG) using Frank orthogonal leads and body surface maps (BSM) including 12-lead ECG. In our study of 11 PD patients (2 men, 9 women), without any seizures and pharmacological treatment and without cardiovascular symptoms, we found marked sinus tachycardia (heart rate 90.1±12.2 min-1) and a shorter R-R interval (678±93.6 ms) than in 27 controls (heart rate 73.6±7.7min-1, R-R 822.7±86.4 ms) (5 men, 22 women) (p<0.001). The VCG measured spatial QRS-STT angle was more opened (70.3±24.5°) than in the control group (49.5±19.5°) (p<0.05). The maximum (extremum) in depolarization (DIAM max 30, 40) and repolarization (RIAM max 35) of body surface isoarea and isointegral (RIIM max) maps was less positive (p<0.001) and the minimum (DIAM min 40) was less negative than in the controls (p<0.05) even in the period free of a panic attack. Our results showed the changes in the heart electric field parameters occurred in PD patients when compared to the control group., K. Pišvejcová, I. Paclt, J. Slavíček, O. Kittnar, A. Dohnalová, E. Kitzlerová., and Obsahuje bibliografii
b1_The aim of our study was to compare the responses of heart rate variability (HRV) with two di fferent types of hormonal substitution therapy (HT) in post-menopausal women (cross-sectional study) and to reveal an effect of HT shortly after beginning of its administration (f ollow-up study). To elucidate the influence of menopause and effects of different protocols of a HT on autonomic control of heart rate, we evaluated the heart rate variability (HRV) in 5 groups: premenopausal women (n=140), postmenopausal women without HT (n=360), women on HT with conjugated estrogen only (n =168), women on continuous combined estrogen-progesterone HT (n=117), and men (n=140). Frequency-domain of short-term stationary R-R intervals was performed to evaluate the total variance, low frequency power (LF; 0.04-0.15 Hz), high freque ncy power (HF; 0.15-0.40 Hz), portion of low frequency power (LF%) and ratio of LF to HF (LF/HF). Significantly lower portion of the LF was found in premenopausal women [46.9 (±2.7) nu] when compared to untreated postmenopausal wome n [54.3 (±2.9) nu] and men [55.2 (±3.0) nu]. Treatment by estrogen only was proved to decrease the LF% [40.1 (±2.1) nu] while no effect on HRV was observed in women treated with combination of estrogen and progesterone [57.2 (±3.1) nu]. Also the HF was lower in postmenopausal wome n [4.16 (±0.16) ms 2 ] than in premenopausal women [4.79 (±0.22) ms 2 ] and women treated with estrogen only [4.98 (±0.25) ms 2 ] while in women treated with combined hormonal therapy the average value [3.99 (±0.21) ms 2 ] did not significantly differ from that of untreated postmenopausal women. The follow-up study also proved increase of high frequency power already after two months of estrogen substitution therapy [4.86 (±0.14) ms 2 vs. 4.19 (±0.15) ms 2 ]., b2_These results suggest that hi gher vagal modulation of heart rate that seems typical for younger women becomes after menopause similar to that of men. We also proved a positive shift of HRV parameters toward more beneficial values as for a cardiovascular risk in postmenopausal women treated with estrogens but not in those treated by combined estrogen - progesterone substitution therapy., S.-G. Yang, M. Mlček, O. Kittnar., and Obsahuje bibliografii a bibliografické odkazy
Spontaneous depolarization similar to that from the sinus node was documented from the myocardial sleeves of pulmonary veins (PV) after isolation procedures. It was then hypothesized that sinus node-like tissue is present in the PVs of humans. Based on a number of features, the myocar dium of myocardial sleeves (MS) is highly arrhythmogenic. Membrane potentials originating from MS are invariably recordable at the PVs ostia in patients with atrial fibrillation (AF) and delayed conduction around the PVs ostia may play a role in re-e ntry process responsible for the initiation and maintenance of AF. Diagnostic and therapeutic evidence of premature atrial beats induced in MS of PVs and resulting in launch of AF was detected by 3D electroanatomic method of monophasic action potential (MAP). MAP recording plays an important role in a di rect view of human myocardial electrophysiology under both physiological and pathological conditions. Its crucial importance lies in the fact that it enables the study of the action potential of myocardial cell in vivo and, therefore, the study of the dynamic relation of this potential with all the organism variables. The knowledge of pathological MAPs from PV myocardial sleeves can help us to confirm a diagnosis when finding the similar action potential morphology. MAP can be also used to evaluate the therap eutic efficiency of vagal nerves suppression, radiofrequency ablation or other treatment procedures in PVs myocardial sleeves as well as for post- treatment following up., O. Kittnar, S.-G. Yang, M. Mlček., and Obsahuje bibliografii a bibliografické odkazy
It has become increasingly apparent in recent years that there are important differences of many cardiovascular disorders including ventricular tachycardias in men and women. Nevertheless, so far just few studies have addressed possible gender differences in electrophysiological characteristics of idiopathic ventricular tachycardia from right ventricular outflow tract (RVOT-VT), other than epidemiological ones. This study explored possible gender differences in electrophysiological characteristics and catheter ablation outcome in RVOT-VT patients. Ninety-three patients (mean age 38.7±15.5 years, 30 males) with idiopathic RVOT-VT were enrolled and analyzed in our study. Male patients had longer QRS width (99.9±19.4 ms vs. 88.4±20.7 ms, p=0.02). Female patients had lower right ventricular mean voltage (3.0±0.7 mV vs. 3.7±0.9 mV, p=0.03), and more low voltage zone over the right ventricular outflow tract free wall (27.0 % vs. 6.7 %, p=0.02). Eighty-one patients passed catheter ablation (23 males). The acute success rate, repeated catheter ablation rate and VT recurrence rate were similar in both genders. The present study provides evidence of the gender differences in electrophysiological findings in patients with idiopathic RVOT-VT. Studies on gender-specific differences in arrhythmia could lead to a better understanding of its mechanism(s) and provide valuable information for the development of optimal treatment strategies., S.-G. Yang, M. Mlček, O. Kittnar., and Obsahuje bibliografii
Operations in the pleural cavity are connected with circulatory changes in pulmonary circulation and general changes of hemodynamics. These changes are influenced by the position of patient’s body on the operation table and by the introduction of artificial pneumothorax. Thoracoscopy is an advanced surgical approach in thoracic surgery, but its hemodynamic effect is still not known. The aim of the present study was to compare the hemodynamic response to surgeries carried out by open (thoracotomy - TT) and closed (thoracoscopy - TS) surgical approach. Thirty-eight patients have been monitored throughout the operation - from the introduction of anesthesia to completing the surgery. Monitored parameters were systolic blood pressure (BPs), diastolic blood pressure (BPd), O2 saturation (SaO2), systolic blood pressure in pulmonary artery (BPPAs), diastolic blood pressure in pulmonary artery (BPPAd), wedge pressure (PW), central venous pressure in right atrium (CVP), cardiac output (CO) and total peripheral resistance (TPR). No significant difference has been found in hemodynamic response between TT and TS groups. Significant changes of hemodynamic parameters occurring during the whole surgical procedure were detected in both technical approaches. The most prominent changes were found after the position of patients was changed to the hip position (significantly decreased BPs, BPd, MAP, SaO2 and BPPAs) and 5 min after the pneumothorax was established (restoration of the cardiac output to the initial value and significant decrease of the TPR). It can be concluded that the thoracoscopy causes almost identical hemodynamic changes like the thoracotomy., S. Trča ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy