How far you can push yourself is up to how you feel. If you have a limit, you will soon
know because you will feel chest or throat discomforts, enough to make you slow down.
After my cabgx3, before it failed due to bad surgery, I pushed myself really hard too,
reaching a pulse of 188 and it felt really good. Only you know your limit and it's good to
find out what it is. If you imagine your heart to be a car engine with a blocked fuel line. You have simply had other fuel lines added to keep the engine running. If the heart tissue is healthy, you should have no limits.