Are there airport identifiers assigned to heliports?
Generally, not all airports have an ICAO or IATA code. Helipads and small airports usually don't rank a code from either of them. IATA won't have any reason to assign a code unless there is some kind of passenger service out of them. ICAO won't have any reason unless there is some significant international service from there. There is more info on the criteria for ICAO codes on this question. Those helipads have FAA identifiers, though.


BSO Public Safety Helistop: FA10
Port Everglades: 2FD4
Broward Health Medical Center: 6FD8


FAA-only ID's have either three or four digits and always contain at least one number.

From the FAA's JO 7350.9K - Location Identifiers (p.1-2-3):


  Two−letter, two−number identifiers are assigned to private−use landing facilities in the United
  States and its jurisdictions which do not meet the
  requirements for three−character assignments. They
  are keyed by the two−letter Post Office or
  supplemental abbreviation (listed below) of the state
  with which they are associated. The two−letter code
  appears in the first two, middle, or last two positions
  of the four−character code.


There are helipads that have IATA and ICOA codes, though. For example, West 30th Street Heliport (IATA: JRA, ICAO: KJRA, FAA: JRA) in New York.