Epilepsy sude. ppl with rapid heartbeats are more likely to have a sude. does that mean fast heartbeats for no reason, or fast heartbeats in general?

It's likely that...: ...Some people with rapid heartbeats have undiagnosed or unknown heart problems. For example, lqts is a relatively recent discovery. http://www.mayoclinic.com/health/long-qt-syndrome/ds00434.

SUDE: It is not clear what actually causes sudden unexplained death. One theory is that prolonged qt interval leads to an arrhythmia. I presume that tachycardia is the result of primary cardiac problem.