Methods: Changes in QRST integral maps after nitroglycerine sublingual application were examined and single dipole best representing the difference QRST integral map was inversely computed.
Inverse method was based on the presumption that small ischemic lesion creates additional generator responsible for changes in surface QRST integral map that can be represented by a single current dipole.
Difference QRST integral maps (DI maps) as a difference between reference QRST integral map of record 0 and QRST integral maps of each record after nitroglycerine application were computed.
To confirm health condition of considered healthy subjects, their QRST integral maps were compared with available template (obtained from 72 healthy people measured in 32 leads according to Lux (4)) and departure QRST integral maps representing deviations from QRST integral map template were computed.
Features of the new ECU include drive-by-wire speed control, a proactive closed loop air/fuel control, an integral map
sensor for load compensation, engine temperature compensation and complete engine diagnostics.
In the group of arrhythmia patients, QRST integral map variability amplitudes increased significantly compared to the healthy group, while the random character of the pattern changes persisted.
Similarly, in normal subjects the autocorrelation functions of the KL components revealed a respiration dependent integral map pattern modulation.
Correlation matrices of QRST integral map coefficients (Only the first 6 KL coefficient correlations of the patients shown in Figure 1 are presented) KL1 KL2 KL3 KL4 KL5 KL6 KL1 1.
Beat-to-beat QRST integral maps, Karhunen-Loeve coefficient time-series ([KL.
In order to detect the susceptibility to ventricular arrhythmias, maps were recorded with different lead systems by different authors and, in particular, various methods of analysis of BSPM have been used to study repolarization potentials: QRST integral maps, eigenvector analysis, principal component analysis, autocorrelation analysis.
Eigenvector analysis was applied to QRST integral maps of 2 groups of patients with old myocardial infarction (11 patients with episodes of sustained ventricular tachycardia and 62 without arrhythmias) and in a control group of healthy subjects (3).
Because the nondipolar content did not perform well in their study population, the authors examined how individual eigenvector pattern contributes to QRST integral maps in each group of patients.