Osteoporosis and heart valve disease

Hi everyone, I am a 76 yo woman with osteoporosis and also a heart condition of mitral and tricuspid valve stenosis and regurgitation. I had an episode of right side chest pain, went ER and not heart attack discharged, Cardiac cat ruled out coronary artery disease but found small hiatal hernia. For the past few weeks when on the treadmill at 1.7 after 10-15 minutes (used to do 30 minutes) or stressed I get the same right sided pain around the upper R breast and the area under the arm pit sometimes lasting up to 12+ hours. Cardiologist doesn’t feels it is cardiac but rather gastric (I guess like heartburn rather than cardiac). He told me to get Pepsid AC and Mylanta but learned Mylanta recently changed formula calcium carbonate like tums and most others.. That is the background.

Questions: Is it ok to take antacid with calcium (like tums etc) on occasion for immediate relieve of the pain? Is there anyone else with both osteoporosis and heart valve (stenosis/regurgitation) issues and how do you handle it when you have heartburn? THANK-YOU !