14 CFR § 67.311 - Cardiovascular.
Cardiovascular standards for a third-class airman medical certificate are no established medical history or clinical diagnosis of any of the following:
(a) Myocardial infarction;
(b) Angina pectoris;
(c) Coronary heart disease that has required treatment or, if untreated, that has been symptomatic or clinically significant;
(d) Cardiac valve replacement;
(e) Permanent cardiac pacemaker implantation; or
(f) Heart replacement.