“…Using multifractal HRV analysis, the majority of authors have implied, that in healthy individuals a higher degree of complexity and stronger anti-correlation with vagal predominance exist during the night (nighttime period), whereas a lesser degree of complexity and a weaker anti-correlation behavior with sympathetic domination occurs during the day (daytime period) [6,16,17,20]. Whether invasive medical or surgical procedures can affect the circadian patterns as assessed my multifractal approach and thus subjecting patients to additional risk by enhancing neurohumoral instability with additionally pronounced transitions between more and less anti-correlated states, remains unveiled [18,21,22].…”