Do people with dextrocardia have other cardiac problems? are they expected to have normal lifespan?

Depends on type: Dextrocardia has different types. Isolated vs situs inversus. Situs inversus has a whole array of intestinal pulmonary and cardiac issues that one may be prone to but most are healthy. Where as isolated dextrocardia may have pulmonary circulation issues accompanying it. Most common cause is due to ekg error in lead placement yielding the appearance of dextrocardia on ekg.