I took diet pills in the 60s. Preludin, I think. Any risk like heart from those?

Phenmetrazine. Preludin is an amphetamine, removed from the us market because of its potential for abuse and addiction. During use, it can cause acute cardiac side effects but it doesn't cause the late heart disease (valve problems) like other diet pills. If you survived the 60s (obviously) and don't use now, you're ok.