This one I hadn't heard of : reducted heart rate variability can increase your risk of dying. Note: the average age in the study was 72. "Reduced heart rate variability and mortality risk in an elderly cohort. The Framingham Heart Study.
"A 1 SD decrement in low-frequency power (natural log transformed) was associated with 1.70 times greater hazard for all-cause mortality (95% confidence interval of 1.37 to 2.09). CONCLUSIONS: The estimation of heart rate variability by ambulatory monitoring offers prognostic information beyond that provided by the evaluation of traditional risk factors." ncbi.nlm.nih.goventOpen ↗ rez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_u- ids=8044959&itool=iconabstr
