Sudden cardiac death and geomagnetic activity: links to age, gender and agony time

In previous studies, we analyzed sudden cardiac death (SCD) of shorter and longer agony time with geomagnetic activity (GMA) levels, with controversial results. The goals of the present study were (1) to study SCD at ages below 65 and 65 and older for each gender on days of low (Io) and higher (IIo-IVo) GMA; (2) to compare links between SCD and GMA with death at 1 h and from 1 to 24 h.

We studied 1327 SCD, 392 (29.5%) females and 935 (70.5%) males, from the Kaunas Registry (part of the MONICA Study): 785 deaths during 1826 consecutive days (1994-1998) at ages 25 to 64 years and 524 deaths at ages 65 and older during 732 consecutive days (1996-1997). Of these, 261 SCD occurred at 1 h, 1076 between 1 h and 24 h without prodromes. GMA data were obtained from the National Geophysical Data Center and the National Space Services Center, USA. Student t-test and its probabilities for daily SCD at Io and IIo-IVo GMA were compared.

The daily number of SCD was significantly different for most of the compared groups at lowest and higher GMA levels. For all SCD, both at age <65 and at >65, the frequency was significantly higher on days of IIo-IVo GMA than on days of Io GMA (p=0.00067-0.03). A strong trend for more SCD on days of Io GMA was seen in males aged <65 who died within 1 h (p=0.06); females aged <65 who died within >1 h to 24 h (p=0.06), and females >65 who died within 1 h (p=0.0267). Females below the age of 65 who died in less than 1 h showed a trend toward higher SCD frequency at IIo-IVo GMA that did not achieve significance (p=0.057).

The distribution of SCD, with short (< or =1h) and longer (1-24 h) time of death, on days of lowest (Io) GMA differs from that on days of unsettled, active, or stormy (IIo-IVo) GMA. Despite the general trend to higher SCD frequency at IIo-IVo GMA, certain rapidly dying groups (< 65 y males, > 65 y females) showed a strong trend toward higher numbers of SCD at the lowest GMA.