a dr told me from an ultra sound of my heart that I have a weak heart and 2 leaky valves, and I have a pacemaker for the last 8 years and hadn t had any problems, did notice a shortage of breathe, is why the dr wanted an ultra sound, and also a stress test, started changing my meds and I was shorter on breathe than I had been before, how can I strengthen the heart and the leaky valves