[Diagnostic capabilities of impedance cardiography method in pulmonary hypertension]. / Impedanskardiografijos metodo galimybes diagnozuojant plauciu hipertenzija.

UNLABELLED: THE OBJECTIVE OF THIS STUDY was to investigate the associations among clinical, impedance cardiography, echocardiography, and chest roentgenography data in diagnosis of pulmonary hypertension for patients with cardiovascular and pulmonary diseases. MATERIAL AND METHODS: Pulmonary artery pressure was measured by impedance cardiography method in 181 patients: 80 patients with cardiovascular pathology when pulmonary hypertension was determined by echocardiography, 69 patients with cardiovascular pathology when pulmonary hypertension was not observed using echocardiography, 19 patients with pulmonary pathology when pulmonary hypertension was determined by echocardiography, and 13 patients with pulmonary pathology when pulmonary hypertension was not observed using echocardiography. Clinical data, parameters of impedance cardiography, echocardiography, and chest roentgenography were evaluated. RESULTS: Pulmonary hypertension (impedance cardiography) was diagnosed by computed mean blood pressure in pulmonary artery with a sensitivity and specificity of 72% and 90%, respectively, and by systolic blood pressure with a sensitivity and specificity of 96% and 90%, respectively. A mathematical model of binary regression was developed with a 96.7% accuracy to diagnose pulmonary hypertension. The most important parameters of impedance cardiography were systolic blood pressure in pulmonary artery and systolic time index. CONCLUSIONS: Mean and systolic blood pressures in the pulmonary artery, assessed by a computerized impedance cardiogram, are diagnostically valuable parameters. In diagnostic algorithms of pulmonary hypertension, the following features can be used: atrial fibrillation; thrombosis of deep veins; dyspnea; cyanosis; accent of II tone at the auscultation point of the pulmonary valve; systolic murmur at the tricuspid valve area; increased diameter of the pulmonary artery more than ≥ 18 mm on chest x-ray; increased diameter of the right ventricle; systolic blood pressure in the pulmonary artery and systolic time index measured by impedance cardiography method.

Nonlinear dynamics analysis of electrocardiograms for detection of coronary artery disease.

A computerized approach of nonlinear dynamics analysis of electrocardiogram (ECG) signals was applied for the detection of coronary artery disease (CAD). The proposed nonlinear dynamics descriptors were derived from 12-lead rest ECG data, and evaluated by originally developed computer software. Fluctuations of potentials of ECG leads that occur during the period of 20 ms with a magnitude of 5-20 microV were significantly less beat-to-beat predictable in ischemic versus non-ischemic patients. The well-known nonlinear dynamics descriptors, recurrences percentage, mutual information, fractal dimension, and a new descriptor, next embedding dimension error, were good quantitative descriptors of fluctuations. They were significantly different (< p = 0.00001) in males with (108 patients) and without (54 patients) coronary artery lesions. The analysis of small fluctuations required a careful preprocessing technique based on knowledge of specifics of measurement errors and physiology of ECG signals. We considered finite differences of measured potentials with the time step of 20 ms as the initial source for nonlinear analysis. In nonlinear dynamics analysis, we also included such time moments that only belong to P- and T-waves or baseline drift with small positive slopes that allowed us to extract, under normal conditions, initial halves of P- and T-waves that displayed a better capacity to classify ischemic patients.

[Evaluation of systolic pressure in pulmonary artery by using impedance cardiography method]. / Sistolinio spaudimo plauciu arterijoje vertinimas impedanskardiografijos metodu.

OBJECTIVE: The methods of cardioechoscopy and heart catheterization are commonly used for diagnosis of pulmonary arterial hypertension in clinical practice. The aim of this study was to assess the diagnostic efficacy of impedance cardiography as safe, non-invasive, and cheap method for detection of pulmonary arterial hypertension. MATERIAL AND METHODS: Pulmonary artery systolic pressure was measured by impedance cardiography method in 109 patients: 41 patients with cardiovascular pathology when pulmonary arterial hypertension was determined by cardioechoscopy; 33 patients with cardiovascular pathology when using cardioechoscopy pulmonary arterial hypertension was not observed; 20 patients with pulmonary pathology when pulmonary arterial hypertension was determined by cardioechoscopy; 15 patients with pulmonary pathology when using cardioechoscopy pulmonary arterial hypertension was not observed. Cardioechoscopy results were compared with the results of impedance cardiography. RESULTS: We found a strong correlation between the data obtained by cardioechoscopy and impedance cardiography methods (r = 0.836, p = 0.0001). There was no statistically significant difference in the distributions of cardioechoscopy and impedance cardiography data (p = 0.915), and statistically significant difference was observed between the data of patients with pulmonary arterial hypertension and patients with normal pulmonary artery systolic pressure (p = 0.0001). CONCLUSIONS: After determining the correlation between cardioechoscopy and impedance cardiography methods (r = 0.836, p = 0.0001), computerized impedance cardiography should be considered as an informative method for diagnosis of pulmonary arterial hypertension.

Development of methods for monitoring of electrocardiograms, impedance cardiograms and seismocardiograms.

Cardiovascular diseases remain the main cause of morbidity and mortality in Lithuania, and early detection of those diseases is one of opportunities to reduce this problem. Usage of information technologies including clinical decision support systems, telemedicine networks and computer analysis of cardiac signals, can serve this purpose. Therefore, the presented paper deals with development of a system for the analysis of 12-lead electrocardiograms (ECG), impedance cardiograms (ICG) and seismocardiograms (SCG) in the aim to use it in a wider cardiologic teleconsultative system. Such a complex set of signals makes it possible to monitor the electric (ECG), hemodynamic (ICG) and mechanical (SCG) properties of cardiac activity. The hardware for synchronous recording of 12-lead ECG, ICG and SCG as well as the software containing programs for signal input, recognition, measurement, analysis and data transmission has been developed.

Cardiological telemonitoring in rehabilitation and sports medicine.

The paper presents the development results of teleconsultative cardiology systems and their application in rehabilitation and sport medicine. The first teleconsultative cardiology (TELECARD) system was developed for outpatient departments in the city of Kaunas, using Internet links. It was based on the CompCardioSignal terminal. One branch of the TELECARD system with a mobile CompCardioSignal terminal was used for functional state evaluation of Lithuanian sportsmen during the 2000 Sydney Olympic Games. The examined results have shown that every sportsman responded differently to acclimatization and the TELECARD system provided support to physicians and coaches for making optimal decisions regarding the sportsmen's adaptation and other situations. The final telemetry system was used for rower monitoring. It was based on the new CompCardioSignal terminal with three EASI ECG leads and synchronously recorded motion signals for evaluation of human reaction to physical load. The developed telemonitoring systems were a useful tool for evaluation of human reaction to physical load in rehabilitation and sports activities.

[JT interval changes in acute myocardial infarction following coronary angioplasty]. / Ligoniu, serganciu uminiu miokardo infarktu, JT intervalo kitimai mechanines vainikiniu arteriju rekanalizacijos metu.

OBJECTIVE: The aim of the study was to determine the influence of early reperfusion on the behavior of JT interval in patients with acute myocardial infarction undergoing percutaneous transluminal coronary angioplasty. MATERIAL AND METHODS: Coronary angiography and percutaneous transluminal coronary angioplasty were done for 14 acute myocardial infarction patients. Measurements were performed from 12-lead surface electrocardiogram with "Kaunas-Load" equipment before percutaneous transluminal coronary angioplasty, 5 minutes and 24 hours after it. RESULTS: Immediately after percutaneous transluminal coronary angioplasty there were shortenings of JT and JT dispersion (JTd) and after 24 hours in all the patients prolongation of JT and JTd intervals was observed. CONCLUSIONS: Changes of the repolarization during percutaneous transluminal coronary angioplasty could be related with ischemic myocardial lesion. Early reperfusion has positive impact on the ventricular repolarization.