Granted, there aren't many cases like this, but it's also one of the reasons I'm for treating even if there are no symptoms when a person has a positive test. Just something to consider. :
"We report a case of a 31-year-old man who presented to the emergency department after four episodes of syncope within a 24 h time span. He was found to have symptomatic complete heart block associated with episodes of ventricular asystole lasting 5–6 s. He underwent emergent permanent pacemaker insertion during which he was found to have no underlying rhythm. He was later found to have positive serologies for Lyme disease despite no known exposure to ticks and neither signs nor symptoms of the disease. The pacemaker was ultimately removed due to resolution of his heart block with antibiotic therapy."
casereports.bmj.com/content/2016/bcr-2016-214474