How to easily handle multiple similar cods

I want to search "831" from several columns （ECG1 to ECG20）. I wrote following codes, but them is so lengthy. I wonder if there is a simple and smart way to handle these codes.

Thank you very much.

af$af_exist <- 0

af <- af[ECG1 %in% c("831"), af_exist := 1]

af <- af[ECG2 %in% c("831"), af_exist := 1]

af <- af[ECG3 %in% c("831"), af_exist := 1]

af <- af[ECG4 %in% c("831"), af_exist := 1]

af <- af[ECG5 %in% c("831"), af_exist := 1]

af <- af[ECG6 %in% c("831"), af_exist := 1]

af <- af[ECG7 %in% c("831"), af_exist := 1]

af <- af[ECG8 %in% c("831"), af_exist := 1]

……

af <- af[ECG20 %in% c("831"), af_exist := 1]

>Solution :

af %>%
  mutate(af_exists = +if_any(ECG1:ECG20,~.== "831"))