Adding ECG animation that looping and can change pattern when button clicked

Am I making the title right?

so I made some Cpr simulations, there will be an ECG bar that shows continuous heart waves (1st wave appears, then 2nd wave appears behind it, and so on). What I want is when I pressed button, I want to call the new wave model-lets called it interrupting wave- but only once, if that button clicked), and then come back to the previous pattern. Anyone can give advice how i can make this animation or where I can find some good explanations?

oh and I wanna make that button continuous too, so when I click this button 2 times there will be 2 interrupting waves, and so on.