Circa(ultra)dians of single extrasystoles in chronic respiratory failure versus health at lowland

The circa- and ultradians of the single extrasystoles' frequency in patients with chronic respiratory insufficiency (CRI) in lowlands (Kosice 210 m) were studied by the testing of following null hypotheses: their average frequency as well as rhythmicity is the same as at health.

In 54 elderly males with CRI, mean numbers of supraventricular (SV) and ventricular (VE) extrasystoles were calculated for each 24 hours. The Halberg cosinor regression was used to test the presence of the 24-hour rhythm and its 2nd to 10th harmonics, i.e. ultradians with the period lengths of 12 to 2.4 hours. The resulting approximating function for either extrasystole type included its point, 95% confidence for mean and 95% tolerance for one individual. The results were compared with those obtained at health at alpha = 0.05.

The daily mesors in CRI were 20.9 for SV, for VE 17.6 extrasystoles per hour and subject. This was significantly (20.3 (SV) and 17.0 (VE)) higher than at health. Significant periodic harmonic components were 3 in CRI versus 6 at health for SV and 6 in CRI versus 1 at health for VE. The dominating CRI rhythm was the 8 hour ultradian for SV and circadian for VE while at health the circadian rhythm was leading for every type of extrasystoles.

The most remarkable effect of CRI versus health at lowlands is a marked increase of the frequency of every type of extrasystoles. SV extrasystoles exert more rhythmicity at health while the VE in disease (Tab. 1, Fig. 1, Ref. 20).