We analyzed cycles with periods, tau, in the range of 0.8-2.0 years, characterizing, mostly during 1999-2003, the incidence of sudden cardiac death (SCD), according to the International Classification of Diseases, 10th revision (ICD10), code I46.1. In the tau range examined, only yearly components could be documented in time series from North Carolina, USA; Tbilisi, Georgia; and Hong Kong, in the latter two locations based on relatively short time series. By contrast, in Minnesota, USA, we found only a component with a longer than (= trans) yearly (transyearly) tau of 1.39 years; the 95% confidence interval (CI) of the tau extended from 1.17 to 1.61 years, falling into the category of transyears (defined as a tau and a 95% CI between 1.0 and 2.0 years, with the limits of the 95% CI of the spectral component's tau overlapping neither of these lengths). During the same span from 1999 to 2003 in Arkansas, USA, a component of about 1-year in length was present, and in addition, one with a tau of 1.69 year with a CI extending from 1.29 to 2.07 years, a far-transyear candidate, far-transyears being defined as having a tau with a CI between 1.20 and 2.0 year, with the CI overlapping neither of these lengths. In the Czech Republic, there was also a calendar-yearly tau and one of 1.76 years. In the latter two geographic/geomagnetic areas, the about-yearly and the longer cycles' amplitudes were of similar prominence. The taus are only candidate transyears; the 95% CIs of their taus overlap the 2-year length. When a series on SCD from 1994 to 2003 from the Czech Republic was analyzed, the 95% CI of the transyear's tau no longer overlapped the 2-year length. Transyears were also found in the Czech Republic for myocardial infarctions (MI), meeting the original transyear definition in both a shorter and a longer series. Moreover, in the 1994-2003 series on MI from the Czech Republic, a near-transyear was also found, meeting the definition of a period with a 95% CI overlapping neither precisely 1.0 year nor 1.2 years, along with a far-transyear, defined as a tau between 1.2 and 2.0 years, again with the 95% CI covering neither of these lengths. Herein, we discuss near- and far-transyears more generally in the light of their background in physics and the concept of reciprocal cyclicities.

University of Minnesota Minneapolis MN USA