Will a heart doctor write anything for anxiety?

Maybe/not. In my state most such meds are under tight scrutiny by the Drug Enforcement Admiration and Department of Public Safety. Docs must check a state database before prescribing such meds, which adds another reason to just let your primary doc deal with non heart issues.

Not likely, unfortunately, due to scrutiny and time consuming procedures in order to prescribe and monitor controlled substances. Many cardiologists will rule out heart conditions and refer you back to your primary care doc.