Concept2 makes three types of cardio machines: indoor rower, BikeErg, and SkiErg. All three use a computerized monitor (PM3, PM4, or PM5, depending on age of machine) that supports connecting a heart rate monitor and a mobile app to it. As you work out, the machine sends detailed data (per stroke) to the mobile app, then the app syncs the workouts to the Concept2 Online Log. More information on this from Concept2: https://www.concept2.com/indoor-rowers/motivation/online-logbook-ranking
Once synced to the Online Log, you can view a neat graph of your performance vs. heart rate. Here's one of my workouts for an example: https://log.concept2.com/profile/1145484/log/39783999.
If the built-in functionality is not enough, you can export this data in one of several formats and do your own processing on it.
Concept2 claims that their machines are self-calibrating so that your performance on any machine is directly comparable to any other machine. (With the caveat that the machines are in good condition, properly lubricated, etc.)