Infant diagnosed with WPW

Hi, at my son's one month checkup they noticed a murmur and sent him to a cardiologist for an ECG. He was diagnosed with WPW. I was in shock since I was expecting the ECG to just be precautionary. He isn't having any symptoms. I've had some time to research this defect and my research has me a little concerned. On one hand I read it's not usually life threatening or serious, on the other hand I've read of children "crashing". Is it likely my son will develop symptoms? What exactly should I look for? Is it common to not have symptoms? Any info on this would be great!