If a medication or a medical condition is the cause of constipation, eliminating the offending medication or treating the underlying medical condition may relieve the constipation. However, certain conditions require the use of a medication despite its side effects.
Your heartbeat can be either tachycardic or bradycardic during a heart attack, so no i don't believe you had have a normal pulse rate at the time of a heart attack, normal being around 60-70 beats per minute for an adult. Heart rate does decrease though with age but that doesn't necessarily indicate anything is amiss.
Since your bloodstream is responsible for bringing the oxygen to your muscles, your heart needs to pump a great amount of blood for maintaining the oxygen supply to the muscles that are working. To fulfill this goal, the heart starts beating rapidly and forcefully, which increases the heartbeat. In addition to that, if you are exercising on a hot day, then too, the high temperature coupled with the vigorous activity performed by your heart will result in an abnormal increase in your heart rate.