Ádám Németh

Invasive validation of a new oscillometric device (Arteriograph) for measuring augmentation index, central blood pressure and aortic pulse wave velocity

Background The importance of measuring aortic pulse wave velocity (PWVao), aortic augmentation index (Aix) and central systolic blood pressure (SBPao) has been shown under different clinical conditions; however, information on these parameters is hard to obtain. The aim of this study was to evaluate the accuracy of a new, easily applicable oscillometric device (Arteriograph), determining these parameters simultaneously, against invasive measurements. Methods Aortic Aix, SBPao and PWVao were measured invasively during cardiac catheterization in 16, 55 and 22 cases, respectively, and compared with the values measured by the Arteriograph. Results We found strong correlation between the invasively measured aortic Aix and the oscillometrically measured brachial Aix on either beat-to-beat or mean value per patient basis (r = 0.9, P < 0.001; r = 0.94, P < 0.001), which allowed the noninvasive calculation of the aortic Aix without using generalized transfer function. Similarly strong correlation (r = 0.95, P < 0.001) was found between the invasively measured and the noninvasively calculated central SBPao; furthermore, the BHS assessment of the paired differences fulfilled the ‘B’ grading. The PWVao values measured invasively and by Arteriograph were 9.41 ± 1.8 m/s and 9.46 ± 1.8 m/s, respectively (mean ± SD); furthermore, the Pearsons correlation was 0.91 (P < 0.001). The limits of agreement were 11.4% for aortic Aix and 1.59 m/s for PWVao. Conclusion Aix, SBPao and PWVao, measured oscillometrically, showed strong correlation with the invasively obtained values. The observed limits of agreement are encouragingly low for accepting the method for clinical use. Our results suggest that the PWVao values, measured by Arteriograph, are close to the true aortic PWV, determined invasively.

Effects of coronary revascularization with or without cardiopulmonary bypass on plasma levels of asymmetric dimethylarginine

ObjectivesWe measured and compared serum asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-arginine levels in patients undergoing coronary artery revascularization. MethodsTwo groups of patients with coronary artery disease were subjected to coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass (CPB; n=20) or with off-pump CABG surgery (OPCABG; n=21). Blood samples for measurements of ADMA, SDMA, and L-arginine were withdrawn and determined by liquid chromatography–tandem mass spectrometry from the coronary sinus (CS) and from the peripheral vein. ResultsOn the basis of the intraoperative (CS) samples, ADMA levels rose in the CPB group (F=0.416, P<0.685 and F=14.751, P<0.001 for OPCABG and CPB groups, respectively). A similar significant increase of ADMA was observed in the peripheral blood (F=30.738, P<0.001) during CPB, whereas ADMA levels remained unchanged during OPCABG. The time course of L-arginine levels was significantly different in the blood samples from CS (F=3.255, P<0.05), when compared with samples from the peripheral blood (F=3.255, P<0.05). The values of the L-arginine/ADMA ratio were significantly higher in the OPCABG group at baseline and on the first postoperative day compared with the results of the CPB group (178.29±11.56 vs. 136.28±13.72 and 129.43±7.08 vs. 106.8±6.9 for OPCABG and CPB groups, respectively). ConclusionPlasma levels of ADMA, SDMA, L-arginine, and L-arginine/ADMA ratio are reliable and feasible markers of an early ischemia-reperfusion injury. During CPB operation, the plasma concentration of ADMA increased significantly and remained elevated until the first postoperative day due to extensive ischemia-reperfusion injury caused by CPB.

Ethnic diversity and its spatial change in Latvia, 1897–2011

Utilizing data from five census enumerations of Latvia (including the most recent 2011 census), this study analyzes temporal and spatial trends in ethnic diversity in the country at the national and municipal levels. The measure employed, the ethnic diversity index (EDI), makes possible a more sophisticated interpretation of the dynamics of ethnic diversity than an analysis of the changing percentage shares of Latvias various ethnic groups over time. At the national level, a trend of declining ethnic diversity prior to Latvias incorporation into the Soviet Union was followed by a rapid increase during the Soviet period, before the onset of gradually decreasing diversity during the post-Soviet period. These national-level trends obscure a number of trends evident at the municipal level, including salient (depending on the period) ethnic diversity gradients Rīga–Latvia, cities/towns–countryside, and the east–west. Latvia remains one of the most ethnically diverse countries of Europe, and the study outlines some of the implications of the recent stagnation of regional EDIs at rather high levels for the economic and political life of the country.

Cellular Phone Irradiation of the Head Affects Heart Rate Variability Depending on Inspiration/Expiration Ratio

Background: Mobile phones may have harmful health effects and clinical examinations report ambiguous results of exposure concerning neurophysiological and cardiovascular actions. Materials and Methods: This study investigated heart rate asymmetry (HRA) and heart rate variability (HRV) parameters with 1:2 and 1:1 metronome-paced inspiration/expiration ratios during short-term 1,800MHz GSM cellular phone exposure in 20 healthy volunteers. Results: Significant HRA changes by Porta and Guzik indices were not found on exposure compared to sham exposure. Time-domain HRV parameters on exposure showed significant differences at 1:1 paced, but not at 1:2 paced breathing compared to sham exposure. A mild post-exposure effect was observed regarding root mean square of successive RR-differences. Conclusion: The findings reflect persisting acute effects of GSM handset emission on the autonomic nervous system. Exploring its influences on health status and survival needs further studies. Symmetrical breathing can be used as a sensitizing factor in other HRV/HRA analysis studies.

Monitoring urinary orosomucoid in patients undergoing cardiac surgery: A promising novel inflammatory marker

BACKGROUND Urinary biomarkers might provide non-invasive tool for monitoring of systemic processes. We aimed to investigate the time-course of urinary orosomucoid (u-ORM) excretion after cardiac surgery hypothesizing that u-ORM is an early and sensitive marker of systemic inflammatory activation. METHODS During a 5-day follow-up study we monitored u-ORM levels in cardiovascular patients who underwent on-pump cardiac surgery (n=38). The patients baseline data were compared to healthy control individuals (n=40). u-ORM was measured by a newly developed automated turbidimetric assay and values were referred to urinary creatinine and expressed as u-ORM/u-CREAT (mg/mmol). RESULTS The cardiovascular patients showed slightly increased baseline u-ORM excretion compared to healthy controls (0.29 vs 0.08mg/mmol, p<0.001). After cardiac surgery, a rapid 10-fold elevation in u-ORM/u-CREAT levels was found. The values remained high till the 3rd postoperative day, and they then decreased significantly (p<0.01) on the 5th day after surgery. u-ORM/u-CREAT mirrored well the perioperative tendency of hs-CRP levels, but it did not follow the non-decreasing kinetics of serum ORM concentrations during the follow-up. u-ORM/u-CREAT correlated significantly (p<0.001) with inflammatory parameters (hs-CRP, se-ORM, WBC). CONCLUSIONS We described u-ORM as an early and sensitive marker of inflammatory activation. The rapid elevation of u-ORM/u-CREAT after surgery and its postoperative kinetics could reflect the magnitude of inflammatory response better than serum ORM and similar to hs-CRP. u-ORM measurements might provide a novel non-invasive tool for real-time monitoring of systemic inflammation, however further investigations are required to confirm it.

Aszimmetrikus dimetilarginin: a cardiovascularis betegségek prediktora?

Cardiovascular diseases are the most common diseases worldwide. They are responsible for one third of global deaths and they are the leading cause of disability, too. The usage of different levels of prevention in combination with effective risk assessment improved these statistical data. Risk assessment based on classic risk factors has recently been supported with several new markers, such as asymmetric dimethylarginine, which is an endogenous competitive inhibitor of nitric oxide synthase. Elevated levels of asymmetric dimethylarginine have been reported in obese, smoker, hypercholesterolemic, hypertensive and diabetic patients. According to previous studies, asymmetric dimethylarginine is a suitable indicator of endothelial dysfunction, which is held to be the preceding condition before atherosclerosis. Several researches found positive correlation between higher levels of asymmetric dimethylarginine and coronary artery disease onset, or progression of existing coronary disease. According to a study involving 3000 patients, asymmetric dimethylarginine is an independent risk factor of cardiovascular mortality in patients with coronary artery disease. This article summarizes the role of asymmetric dimethylarginine in prediction of cardiovascular diseases, and underlines its importance in cardiovascular prevention.

Short-term response of metabolic hormones to coronary artery bypass surgery

PURPOSE To explore the response pattern of plasma adipokine and ghrelin levels to coronary artery bypass graft (CABG) surgery in patients with (on-pump) and without (off-pump) cardiopulmonary bypass (CPB). MATERIAL/METHODS Sixteen consecutive patients (age: 62 ± 10 years, male: 10) with obstructive coronary artery disease (CAD) who underwent elective CABG surgery with CPB and intraoperative GIK infusion were selected for on-pump group and 19 CAD patients (age: 63 ± 10 years, male: 16) were included in the off-pump group. Blood samples were taken before, during and after surgery. Intraoperative samples were withdrawn simultaneously for peripheral vein and sinus coronarius (SC). Plasma adipokine concentrations were measured by ELISA, those of ghrelin by RIA kits. RESULTS In response to surgical intervention there was an early, transient fall in plasma levels of adiponectin (p<0.0001) and resistin (p=0.002) followed by an increase to approach their initial values. Plasma ghrelin also increased (p=0.045), this increase, however, was confined to the period of GIK supported CPB. Plasma insulin (p=0.003) and resistin (p=0.009) was significantly higher in the peripheral vein than in SC. The perioperative hormone profile of patients without CPB (off-pump) proved to be comparable to that of on-pump patients in spite of the insulin administration and greater oxidative and inflammatory stress. CONCLUSIONS Adipose tissue-derived factors appear to mediate the metabolic and vascular changes that occur in patients with CABG surgery. Epicardial adipose tissue is unlikely to have major contribution to the development of CAD as adipokines are not elevated in SC independent of the mode of intervention.

The assessment of neural injury following open heart surgery by physiological tremor analysis.

Introduction The appearance of post-operative cognitive dysfunction as a result of open heart surgery has been proven by several studies. Focal and/or sporadic neuron damage emerging in the central nervous system may not only appear as cognitive dysfunction, but might strongly influence features of physiological tremor. Material and methods We investigated 110 patients (age: 34-73 years; 76 male, 34 female; 51 coronary artery bypass grafting (CABG), 25 valve replacement, 25 combined open heart surgery, 9 off-pump CABG) before surgery and after open-heart surgery on the 3rd to 5th post-operative day. The assessment of the physiological tremor analysis was performed with our newly developed equipment based on the Analog Devices ADXL 320 JPC integrated accelerometer chip. Recordings were stored on a PC and spectral analysis was performed by fast Fourier transformation (FFT). We compared power integrals in the 1-4 Hz, 4-8 Hz and 8-12 Hz frequency ranges and these were statistically assessed by the Wilcoxon rank correlation test. Results We found significant changes in the power spectrum of physiological tremor. The spectrum in the 8-12 Hz range (neuronal oscillation) decreased and a shift was recognised to the lower spectrum (p < 0.01). The magnitude of the shift was not significantly higher for females than for males (p < 0.157). We found no significant difference between the shift and the cross-clamp or perfusion time (p < 0.6450). Conclusions The assessment of physiological tremor by means of our novel, feasible method may provide a deeper insight into the mechanism of central nervous system damage associated with open heart surgery.