Lacosamide is an antiepileptic drug that has been approved by the FDA for the treatment of partial-onset seizures in patients with epilepsy [3]. However, there is no clear indication that lacosamide has been tested on heart patients.

The first source [1] provides information on the patent status of lacosamide but does not provide any information on the drug's clinical trials. The second source [2] is a research article that discusses the use of lacosamide in the treatment of epilepsy. While the article mentions that lacosamide has a favorable safety profile, it does not mention any studies that have tested the drug on heart patients.

The third source [3] is the FDA-approved label for lacosamide. The label provides information on the drug's clinical trials, including safety and efficacy data. However, there is no indication that the drug has been tested specifically on heart patients.

In conclusion, based on the provided sources, there is no clear indication that lacosamide has been tested on heart patients. While the drug has been approved by the FDA for the treatment of epilepsy, there is no information available on its use in patients with heart conditions. It is important for patients to consult with their healthcare provider before taking any medication, especially if they have underlying medical conditions.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LACOSAMIDE
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4150657/
[3] https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/022253s042lbl.pdf