SPECTRAL TEMPORAL MAPPING OF THE QRS-COMP LEX IN PATIENTS WITH LIFE-THREATENING CARDIAC-ARRHYTHMIAS

The aim of the study was to investigate changes of some parameters of averaged frequency-temporal and spectral-temporal maps of the QRS-comp lex in patients with life threatening arrhythmias. Ninety eight patien ts with ischemic heart disease and previous myocardial infarction (54 patients without arrhythmia and 44 with attacks of paroxysmal ventricu lar tachycardia) were studied. Standard techniques of detection and an alysis of late ventricular potentials were used. In addition we imploy ed spectral temporal mapping with construction of two- and three-dimen sional maps, automatic detection of local maximal amplitudes of freque ncies in analyzed ranges and graphic reconstruction with sequential co nnection of detected maxima at transition from one frequency bands to another and from the onset of QRS-complex to its terminal part. In con trol group detected maxima as a rule were located within narrow tempor al interval from 40 to 50 ms of the QRS complex. In the group of patie nts with late ventricular potentials without attacks of ventricular ta chycardia 2 - 3 maxima were registered simultaneously In different fre quency bands located at a distance of 15 - 20 ms from each other. Pati ents with ventricular tachycardias had from 3 to 5 temporal intervals in which frequency maxims were detected. These maxima were located in an interval from 30 to 70 ms also at 10 ms from the beginning of the Q RS complex. This was an evidence of pronounced fragmentation of the ex citation wave front and of the process of depolarization of ventricula r myocardium.