As Strangelove mentioned.
You can clinically do Consult Liason psychiatry, or become a researcher in this area.
There are a number of ways psychiatric disorders affects the heart.
Antipsychotics can cause arrhythmias, Depression is correlated with higher homocysteine which does cause damage to the arteries, various SES factors does affect outcomes in heart disease, metabolic problems with psychotropics, etc.
However there is no specialized program of training specifically for psychiatric disorders & the heart, though CL psychiatry probably touches upon this the most. I wouldn't be surprised if in one CL program, there is someone who has made this an equivalent of specialty just out of self interest.