Granger causality based on vector time series and quaternion algebra with possible applications to molecular dynamics data analysis.

Causal analysis plays a significant role in physics, chemistry, and biology. Dynamics of complex (bio)molecular and nanosystems, from the microscopic to the macroscopic scale, are characterized by time-dependent vectors such as positions, forces, momenta, angular momenta, or torques. Identification and analysis of causal relationships between these time-dependent signals is an important problem in the multidimensional time-series analysis and is of great practical importance in describing the properties of such dynamical systems, and to understanding their functionality.

Perfusion defects on real-time myocardial contrast echocardiography predict higher mortality in patients with end-stage renal disease - a 3-year follow-up.

Aim: The aim of this study was to assess the prognostic significance of myocardial contrast echocardiography (MCE) in patients with end-stage renal disease (ESRD) on a 3-year follow-up and to compare the value of MCE with demographic, clinical, and laboratory parameters.

Methods: Fifty-eight ESRD patients on regular dialysis were prospectively screened for coronary artery disease (CAD) using perfusion assessment on real-time MCE. We analyzed the following end points during the 3-year follow-up: death, cardiovascular complications, and combined end point, which consisted of adverse cardiac events mentioned above.

Coronary blood flow in patients with end-stage renal disease assessed by thrombolysis in myocardial infarction frame count method.

Background: Myocardial ischaemia in patients with end-stage renal disease (ESRD) develops both due to the epicardial coronary artery stenosis and to the microvascular injury. We aimed to evaluate coronary blood flow in ESRD patients by means of the thrombolysis in myocardial infarction (TIMI) frame count method (TFC). In patients with ESRD, implementation of the TFC as a marker of the coronary flow abnormalities have not been previously investigated.

Application of myocardial contrast echocardiography for the perfusion assessment in patients with end-stage renal failure--comparison with coronary angiography.

Background: 39 end-stage renal disease (ESRD) patients undergoing elective coronary angiography (CA) were studied.

Method: Myocardial contrast echocardiography (MCE) for the perfusion assessment was done prior to CA. The left ventricle was divided into three regions supplied by left anterior descending (LAD) circumflex (Cx) and right coronary artery (RCA).