Handling heartbeats when using eventsource

Per claudio-scandura example I am creating stream for pushing events to web browser. As a result of adding heartbeat I get a message triggered every second. In my case I am pushing data from server side with specific eventType myEvent which is handled by adding addEventListener(‘myEvent’…). Do I need to add listeners for onmessage to ‘read’ the heartbeat to avoid memory issues or can I just ignore?

  lazy val (sourceQueue, eventsSource) = Source.queue[String](Int.MaxValue, OverflowStrategy.backpressure)
    .delay(1.seconds, DelayOverflowStrategy.backpressure)
    .map(message => ServerSentEvent(message, Some("myEvent")))
    .keepAlive(1.second, () => ServerSentEvent.heartbeat)