But about a week ago, he started having pains in his chest. The Arkadelphia resident immediately had it checked out by his primary care physician, who decided to do an EKG.
"A nuclear stress test is a way that we test patients. One to detect the presence of coronary artery disease. Or if we know they have coronary artery disease, to see any blockages they may have," says cardiologist Charles Clogston.
He goes on to describe a nuclear stress test as a non-invasive method to look at the blood flow to your heart muscle at rest and while exercising and is basically done in three stages.
"Patients will come in and they will have an IV. Once the IV is started, they are injected with a radio pharmaceutical medicine called cardiolight."
A cardiolight basically travels through the bloodstream and is taken up by the heart muscle. It allows doctors to use a special camera to take pictures of the heart and see where the radioactivity is going.
"The next step is we do a stress test where we walk on a treadmill or use a medication to simulate stress. We'll give another injection of the radiopharmaceutical and take another set of pictures to compare. So now, we have stress pictures to compare with rest pictures."
The test itself is low-risk and only takes a few hours, and the results can be life-saving.
For Estes, that means it's back to working outdoors and his weekly aerobics class for seniors.