We greatly appreciated the interesting paper by Song et al regarding the chronobiological occurrence of Tako-tsubo cardiomyopathy (TTC). The Authors, collecting a sample of 137 patients in two tertiary cardiovascular centers in Korea, reported preferred peaks of occurrence in summer, Monday, and morning. Although summer and morning peaks represent confirmed evidence in the available literature, this studies provides further support to the only previous study reporting a Monday peak in occurrence of TTC, not included in the reference selection. The Takotsubo Italian Network investigators, in fact, investigated their cohort of consecutive patients (n=112, years 2002-2008) and found a statistically significant circaseptan (about 7-day) rhythm characterized by a peak on Monday and nadir on Saturday (p<0.05). However, the observed versus expected distribution of admissions between weekend and weekdays was not significantly different. It has to be stressed that the weekly variation observed by Song et al was obtained by conventional statistics (chi-square test), that allows one to demonstrate differences between frequency rates. In turn, we used a validated chronobiological method based on inferential Fourier analysis (ChronoLab), written to explore cyclical phenomena and to demonstrate a repetitivity of the analyzed phenomenon.
Temporal occurrence of Takotsubo cardiomyopathy: A further evidence for a Monday peak
MANFREDINI, Roberto;FABBIAN, Fabio;
2013
Abstract
We greatly appreciated the interesting paper by Song et al regarding the chronobiological occurrence of Tako-tsubo cardiomyopathy (TTC). The Authors, collecting a sample of 137 patients in two tertiary cardiovascular centers in Korea, reported preferred peaks of occurrence in summer, Monday, and morning. Although summer and morning peaks represent confirmed evidence in the available literature, this studies provides further support to the only previous study reporting a Monday peak in occurrence of TTC, not included in the reference selection. The Takotsubo Italian Network investigators, in fact, investigated their cohort of consecutive patients (n=112, years 2002-2008) and found a statistically significant circaseptan (about 7-day) rhythm characterized by a peak on Monday and nadir on Saturday (p<0.05). However, the observed versus expected distribution of admissions between weekend and weekdays was not significantly different. It has to be stressed that the weekly variation observed by Song et al was obtained by conventional statistics (chi-square test), that allows one to demonstrate differences between frequency rates. In turn, we used a validated chronobiological method based on inferential Fourier analysis (ChronoLab), written to explore cyclical phenomena and to demonstrate a repetitivity of the analyzed phenomenon.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
