Scopul nostru este sprijinirea şi promovarea cercetării ştiinţifice şi facilitarea comunicării între cercetătorii români din întreaga lume.
Autori: Dinca-Panaitescu S, Dinca-Panaitescu M, Achim A, Negoescu R
Editorial: Integrative Physiological and Behavioral Science, 34(1), p.10-18, 1999.
Seventeen male subjects, aged nineteen to twenty, went through a protocol
including, while supine, relaxation at rest (10 min) and mental stress (MS) by a Kraepelin (arithmetic) test (5 min), as part of a larger study. With a polygraphic analog recording set-up we also collected a 1 ms – digital facsimile of a lead II-like thoracic ECG with maximum T-wave (Codas, Dataq Instr).
Twenty-three stress responses were assigned to three classes according to known cardiotacho-, plethysmo-, and pneumo-graphic marks of „concentrated attention mainly,” „emotion,” or still „high emotion.” During each setting the most stationary 3 min RR epoch in cardiotachogram was selected for joint RR & QT beat-by-beat variability study. RR and QT intervals were detected using a published algorithm. Conventional RR and QT Fourier autospectra were computed, while using RR*QT mean square coherence spectrum we detached the RR-independent, idioventricular (IV) fraction of QT low frequency (LF: 0.04-0.15 Hz) power of variability (IV QT-LF). IV QT-LF responded consistently to varieties of mental stress that confuse RR-LF or let QT-LF unchanged, best witnessing the cortically-issued ventricular adrenergic strain. Indeed, while emotion propels the same way all spectral variables above, concentrated attention increased (Wilcoxon) significantly IV QT-LF only (0.54-0.80 ms2) and decreased RR-LF (715-463 ms2). Findings hold promise of a non-invasive, high resolution Holter based monitoring of sympathetic status of myocardium, robust vis-a-vis of confusion caused by the autonomic interplay at sino-atrial node.
Cuvinte cheie: high-resolution Holter ECG, RR & QT variability analysis