Yoga covers a wide field from the predominantly physical like hata yoga to the purely spiritual like Kundalini yoga.
Likewise, heart disease
covers a whole lot of conditions like:
angima, myocardial infarction
, coronary artery disease, septal defects, valve defects, cardiomyopathy
, palpitations and more.
Doing the wromg yogic practice for the wrong condition can make things worse than they are.
First thing is to get a proper assessment of the cardiac condition. Then get an opinion from a yoga expert. After which get the cardiologists opinion on whether the suggested yoga is suitable.
Finally, a decision based on one's own study of all info.