SADS is short for "sudden arrhythmic death syndrome," which was first identified in 1977. Underlying factors for SADS (both the sudden adult death and sudden arrhythmic versions) include undiagnosed myocarditis, inflammatory conditions and other conditions that cause irregularities in the electrical system of the heart, thereby triggering cardiac arrest.
The prevalence of this previously rare event jumped markedly in the 2020s. Increased COVID-related SCD (sudden cardiac death), as it is also termed, appears to be due, at least in part, to a recent history of infection and/or vaccination that induces inflammatory and immune impairment that injures the heart.
Before the SARS Cov-2 pandemic, SADS was rare and with scant research on it except to mention that it accounted for about 30% of unexpected cardiac deaths among young people. The British Office for National Statistics (ONS) lists a total of 128 cases of SADS (all age groups, whether listed as cardiac-related or unknown) in 2016, 77 cases in 2017, 70 in 2018, 107 in 2019 and 139 cases in 2020.
Among athletes, sudden death incidence has historically ranged between 1 in 40,000 and 1 in 80,000. An analysis of deaths among competitive athletes between 1980 and 2006 in the U.S. identified a total of 1,866 cases where an athlete either collapsed from cardiac arrest and/or died suddenly. That's 1,866 cases occurring over a span of 27 years, giving us an annual average of 69 in the U.S.
Data compiled by the International Olympic Committee show 1,101 sudden deaths in athletes under age 35 between 1966 and 2004, giving us an average annual rate of 29 sudden deaths, across all sports. Meanwhile, between March 2021 and March 2022 alone -- a single year -- at least 769 athletes have suffered cardiac arrest, collapse, and/or have died on the field, worldwide.
Among EU FIFA (football/soccer ball) athletes, sudden death increased by 420% in 2021. Historically, about five soccer players have died while playing the game each year. Between January and mid-November 2021, 21 FIFA players died from sudden death.
Good Sciencing, which is keeping a running total of athletic deaths following injection for SARS-Cov2 puts the current number of cardiac arrests at 1,090 and total deaths at 715. Several dozen more are pending confirmation that the athlete had in fact received the shot.
While general population data on SADS incidence for 2021 and 2022 are hard to come by, incidence has risen sufficiently enough to cause concern in some countries. The Melbourne Baker Heart and Diabetes Institute in 2022 set up a new SADS registry to gain more information" about the phenomenon. According to a spokesperson, at this time there are approximately 750 SADS cases per year in Australia; the equivalent average death toll in the U.S. is said to be around 4,000.