Ca2+ perkrovos sukeltas mitochondrijų NAD(P)H išeikvojimas, nesusijęs su nespecifinio laidumo virsmu

Kauno medicinos universiteto Biomedicininių tyrimų institutasVytauto Didžiojo universiteta

Peculiarities of multivariate analysis based methods for detection and evaluation of ECG T-wave alternans

Two multivariate analysis methods based on Principal Component Analysis and Periodic Component Analysis designed for detection and evaluation of ECG T-wave alternans were tested on synthetic and clinical recordings in the aim to reveal their diagnostic features. Advanced data pre-processing including normalization of S-T,T segment duration by means of bicubic interpolation was used to increase methods reliability. Non-visible variations in shape of S-T,T segment were revealed by means of the methods in the recordings registered in severe cardiac situations. Results lead to the idea, that analysis of T-wave alternans could be used not only for prevention of critical cardiac situations, but give valuable additional diagnostic information about status of cardiologic patients during ordinary examination

EKG P-bangos klasių skaičiaus parinkimas, tikrinant statistines hipotezes apie pasiskirstymo tolygumą

Cardiac output is controlled by the autonomic nervous system by changing the heart rate and/or the contractions of the heart muscle in response to the hemodynamic needs of the whole body. This control is a result of permanent competition between the sympathetic and the parasympathetic nervous systems. Malfunction of these mechanisms causes the postural orthostatic tachycardia syndrome and/or the chronic fatigue syndrome. Evaluation of functionality and efficiency of the control mechanisms can give valuable diagnostic information in the early stages of dysfunction of the heart control systems and help to monitor the healing process or rehabilitation period after interventions. Quantitative evaluation of ECG P-wave changes evoked by an orthostatic test (which evokes a sudden misbalance in the interplay between the sympathetic and the parasympathetic heart control) by using a newly developed method based on the principal component analysis and clusterization by testing statistical hypothesis of uniformity provides a quantitative estimate for functionality and efficiency of the heart rate control mechanisms.Širdies veikla autonomiškai reguliuojama priklausomai nuo organizmo aktyvumo ir su tuo susijusios medžiagų apykaitos (metabolizmo) intensyvumo. Reguliavimą atlieka konkuruodamos simpatinė ir parasimpatinė nervų sistemos. Šių reguliacinių mechanizmų sutrikimai sukelia ortostatinę tachikardiją, nuolatinio nuovargio sindromą. Kiekybinių EKG P-bangos formų vertinimas ortostatinio mėginio metu atliktas naudojant pagrindinių komponenčių analizę ir įverčių klasterizaciją, tikrinant statistines hipotezes apie duomenų pasiskirstymotolygumą, suteikia diagnostiškai svarbios informacijos ankstyvuose reguliacinių sutrikimų perioduose bei leidžia vertinti reguliacinių sistemų atsitatymą po intervencijų, sutrikdžiusių normalų jų funkcionavimą

Predictors of 30-Day In-Hospital Mortality in Patients Undergoing Urgent Abdominal Surgery Due to Acute Peritonitis Complicated with Sepsis

BACKGROUND Sepsis is a life-threatening condition with high morbidity and mortality rate. Identifying early prediction factors of critical situations in intra-abdominal sepsis patients can help reduce mortality rates. This prospective study was carried out to evaluate the association of technically available factors with 30-day in-hospital mortality. MATERIAL AND METHODS There were 67 intra-abdominal sepsis patients included in the study; patients were observed for 30 days postoperatively. The data was processed using SPSS24.0 statistical analysis package. All tests that had a significance level of 0.05 were selected. RESULTS Septic shock in association with increase in age per year showed increase the odds of mortality and prognosed 30-days in hospital mortality correctly in 79% of cases. The observed OR was 12.24 (P/=70 years), time from peritonitis symptoms to surgery prognose mortality with accuracy of 82%. The most accurate model to prognose 30-day in-hospital mortality included the presents of septic shock, age, time from peritonitis symptoms to surgery, drop of MAP <65 mmHg) post-induction, the odds of mortality 8.86 (P=0.001). Severe hypotension post-induction was more frequent in patients who were not diagnosed with sepsis (P=0.035). CONCLUSIONS The present study revealed a simple indicator for the risk for death under diffuse peritonitis patients complicated with sepsis. Septic shock, increase in age per year, peritonitis symptoms lasting more than 30 hours, and severe hypotension post-induction had a negative prognostic value for mortality in patients with intra-abdominal sepsis, and might be a high risk for 30-day mortality

Prognosis of In-Hospital Myocardial Infarction Course for Diabetic and Nondiabetic Patients Using a Noninvasive Evaluation of Hemodynamics and Heart Rate Variability

Background and Objective. The objective of our study was to investigate whether the combination of markers of heart rate variability (HRV) and impedance cardiography (ICG) help evaluate the risk of in-hospital death, ventricular arrhythmia, or complicated course secondary to myocardial infarction (STEMI) and to clarify whether combined analysis of HRV and ICG improve prognosis of STEMI, comparing 3 groups: 1) diabetic, 2) nondiabetic, and 3) diabetes-unselected patients. Material and Methods. The parameters reflecting heart rate variability and central hemodynamics were estimated from a 24-hour synchronic electrocardiogram and thoracic impedance signal recordings in 232 patients (67 diabetic) on the third day after myocardial infarction. Logistic regression analysis was used to determine the predictors of selected outcomes. Different prognostic models were compared with the receiver operating characteristic curve analysis.Results. The model consisting of low- and high-frequency power ratio (LF/HF) and cardiac output (CO) was elaborated for the prognosis of in-hospital death in the group 3 (odds ratios [ORs] were 9.74 and 4.85, respectively). Very low-frequency power (VLF), cardiac index (CIN), and cardiac power output (CPO) were the predictors of ventricular arrhythmia in the group 2 (ORs of 1.005, 5.09, and 66.7, respectively) and the group 3 (ORs of 1.004, 3.84, and 37.04, respectively). The predictors of the complicated in-hospital course in the group 1 were the baseline width of the minimum square difference triangular interpolation of the highest peak of the histogram of all NN intervals (TINN) and stroke volume (SV) (ORs of 1.006, and 1.009, respectively); in the group 2, the mean of the standard deviations of all NN intervals for all 5-minute segments of the recording (SDNN index) and CPO (ORs of 1.06 and 2.44, respectively); and in the group 3, SDNN index, VLF, LF/HF, CIN (ORs of 1.04, 1.004, 2.3, and 3.49, respectively). Conclusions. The patients with decreased HRV and low estimates of central hemodynamics evaluated by ICG are at an increased risk of the adverse in-hospital course of STEMI. The combined analysis of HRV and ICG hemodynamic estimates contributes to the risk assessment of the complicated in-hospital course of STEMI, in-hospital hemodynamically significant ventricular arrhythmia, and in-hospital death secondary to STEMI. The in-hospital prognostic value of the combined estimates of HRV and ICG is lower in the STEMI patients with diabetes mellitus as compared with the nondiabetic patients

In Vivo Monitoring der Vitalitat von Herzgewebe durch die kombinierte Aktivitat

A prototype system for in vivo monitoring of the heart tissue viability by using combined measurements of fluorescence, thermography and electrical activity has been elaborated for cardiac surgery. The fluorescence imaging of nicotinamide adenine dinucleoticle NAD(P)H in the blue light range (lambda=467 nm) by using UV light (X=347 nm) excitation was used to detect metabolic disturbances. The method of the principal component analysis was used for the processing of the fluorescence image sequences. Far infrared (lambda=7.5-13 mu m) imaging was used to evaluate temperature dynamics of the tissue surface during circulation disturbances. Evaluation of the epicardial electrogram shape by using continuous wavelet transform was used to detect and evaluate ischemia-caused disturbances of the electrical activity of the tissue. The combination of temperature, fluorescence and electrical activity estimates obtained from synchronically registered parameters during the experiments on model systems and experimental animals yielded qualitatively new results for the evaluation of cardiac tissue viability and enabled to achieve a versatile evaluation of the heart tissue viabilityKauno medicinos universiteto Biomedicininių tyrimų institutasKauno medicinos universiteto Kardiologijos instituta

Detection and evaluation of ventricular repolarization alternans: An approach to combined ECG, thoracic impedance, and beat-to-beat heart rate variability analysis

Background and objective: Beat-to-beat alteration in ventricles repolarization reflected by alternans of amplitude and/or shape of ECG S-T,T segment (TWA) is known as phenomena related with risk of severe arrhythmias leading to sudden cardiac death. Technical difficulties have caused limited its usage in clinical diagnostics. Possibilities to register and analyze multimodal signals reflecting heart activity inspired search for new technical solutions. First objective of this study was to test whether thoracic impedance signal and beat-to-beat heart rate reflect repolarization alternans detected as TWA. The second objective was revelation of multimodal signal features more comprehensively representing the phenomena and increasing its prognostic usefulness. Materials and methods: ECG, and thoracic impedance signal recordings made during 24 h follow-up of the patients hospitalized in acute phase of myocardial infarction were used for investigation. Signal morphology variations reflecting estimates were obtained by the principal component analysis-based method. Clinical outcomes of patients (survival and/or rehospitalization in 6 and 12 months) were compared to repolarization alternans and heart rate variability estimates. Results: Repolarization alternans detected as TWA was also reflected in estimates of thoracic impedance signal shape and variation in beat-to-beat heart rate. All these parameters showed correlation with clinical outcomes of patients. The strongest significant correlation showed magnitude of alternans in estimates of thoracic impedance signal shape. Conclusions: The features of ECG, thoracic impedance signal and beat-to-beat variability of heart rate, give comprehensive estimates of repolarization alternans, which correlate, with clinical outcomes of the patients and we recommend using them to improve diagnostic reliability

Širdies audinių temperatūros stebėsena ir nuosruvių funkcijos įvertinimas kardiochirurginių operacijų metu

Thermography is a relatively new contact-free method used in experimental and clinical studies and in cardiovascular surgery to investigate the myocardium and coronary artery function. Objects of complex study included mongrel dogs and patients with coronary artery disease who underwent cardiac surgery. For active dynamic thermography, we used a thermovision camera “A20V” (FLIR Systems, USA). Our data indicate that both experimental and clinical study performed on beating hearts could be an important approach to interoperation inspection of autovenous graft function. An infrared camera also can be successfully used to determine the extent of ischemic damage to the myocardium, heart, and blood vessels during surgery as a significant prognostic tool for evaluating outcome after cardiac operation