The current study investigates race-ethnic differences in rates of panic disorder, panic attacks and certain panic attack symptoms by jointly combining three major national epidemiological databases. The compared groups were White, African American, Latino and Asian. The White group had significantly higher rates of panic disorder, and of many panic symptoms, including palpitations, as compared to the African American, Asian and Latino groups.
Here's a table which shows more detail:
The rates tend to go like this: Caucasian > African > Hispanic > Asian, but clearly whites are higher than the rest.
According to this study, heritability for panic disorder is .44.