the electrical conduction pathways of the heart were likely interrupted and impinged upon by monocytes/macrophages which have migrated to heart tissue to attack vaccine generated Spike protein that is present in heart muscle tissue, the physical exertion & impact increases the likelihood & triggers the otherwise very rare Q on T V-fib
Sad thing is that this was foreseen:
https://www.iat.uni-leipzig.de/datenbanken/iks/sponet/Record/4073277