Cardiac stress test
Yesterday I had a cardiac stress test. Since I have been participating in a cardiac rehab program for the past six weeks or so, I assumed that the stress test would be relatively easy. Remember the cliche about assuming. I soon learned how wrong my assumptions were. In the rehab program I usually get 40 - 45 minutes of consistent cardio exercise 3 times a week, along with a series of exercises with free weights. Then I usually walk between 2 and 3 miles 2 or 3 of the remaining days.
The stress test is designed to monitor the heart function in varying conditions. It begins with the insertion of an IV for the puropse of injecting a radioactive isotope and also for a saline solution while on the treadmill. The isotope used was "technesium". It emits gamma rays and has a half-life of about 6 hours. I believe it does not occur in nature. I then climbed onto the bed of a machine that was a gamma detector. In some ways it resembles a MRI in that the bed moves into the heart of the detector. It takes about 15 - 20 minutes to complete this phase of the examination. Piece of cake, huh? I was then taken to the treadmill where I was connected to a EKG machine and the saline solution. While standing still they recorded a baseline EKG. They also recorded my blood pressure. My pulse rate was about 59. Then the treadmill began to move; about 2.5 mph, I think. I notice the pulse has climbed to 65 or 70. No sweat. A minute or two later the speed increased, along with the incline. Again the speed increased, perhaps to 3.5 along with the incline. My pulse was now about 75-80. The target rate for me was 134 or 85% of miximum. The speed increased, now to 4 mph and the incline got steeper. All the time they were monitoring the EKG. My pulse was perhaps 90, still a long way from 134. The speed became 4.5 and now it feels like I am walking, no, racing straight uphill. I had come prepared to wear shorts, but it felt cool in the office when I began so l left my jeans on. My normal walking speed is about 3 to 3.5 mph. I was beginning to get tired and knew I had a long way to go. My pulse was perhaps 95 to 100. The speed now went to 5.0 mph and the incline increased again. I no longer was able to walk. Jogging or running became necessary. I was becoming exhausted. Still my pulse was only about 110. Every minute or so the tech would ask how I was doing. I would answer ,"fine". I eventually began to wonder if I was giving the wrong answer. She then told me it was part of her job to ask. I was now hanging on to the railings to keep from falling off the treadmill. After another couple of minutes my pulse climbed to 120. After what seemed like hours (it was probably only a couple of minutes) my pulse reached the requisite 134. They needed a sustained 134. Perhaps a minute later I reached that level. They still needed to record another minute of activity at that level. They had commented that it had taken a lot to break past the atenalol barrier. Apparently, atenalol is a drug that reduces the pulse rate. Once they recorded what they needed the treadmill was slowed to a stop. They place a chair on the treadmill for me to collapse into.
Once I recovered sufficiently to stand, they sent me to the caffeteria for coffee and a muffin and instructed me to return in about 40 minutes. When I returned the gamma radiation was again recorded, this time with 3 leads connected so that the recordings could coincide with my heartbeat. In approximately another 15 minutes my test was completed.
I have no report of the results, but was told by the tech that no news is good news.
The stress test is designed to monitor the heart function in varying conditions. It begins with the insertion of an IV for the puropse of injecting a radioactive isotope and also for a saline solution while on the treadmill. The isotope used was "technesium". It emits gamma rays and has a half-life of about 6 hours. I believe it does not occur in nature. I then climbed onto the bed of a machine that was a gamma detector. In some ways it resembles a MRI in that the bed moves into the heart of the detector. It takes about 15 - 20 minutes to complete this phase of the examination. Piece of cake, huh? I was then taken to the treadmill where I was connected to a EKG machine and the saline solution. While standing still they recorded a baseline EKG. They also recorded my blood pressure. My pulse rate was about 59. Then the treadmill began to move; about 2.5 mph, I think. I notice the pulse has climbed to 65 or 70. No sweat. A minute or two later the speed increased, along with the incline. Again the speed increased, perhaps to 3.5 along with the incline. My pulse was now about 75-80. The target rate for me was 134 or 85% of miximum. The speed increased, now to 4 mph and the incline got steeper. All the time they were monitoring the EKG. My pulse was perhaps 90, still a long way from 134. The speed became 4.5 and now it feels like I am walking, no, racing straight uphill. I had come prepared to wear shorts, but it felt cool in the office when I began so l left my jeans on. My normal walking speed is about 3 to 3.5 mph. I was beginning to get tired and knew I had a long way to go. My pulse was perhaps 95 to 100. The speed now went to 5.0 mph and the incline increased again. I no longer was able to walk. Jogging or running became necessary. I was becoming exhausted. Still my pulse was only about 110. Every minute or so the tech would ask how I was doing. I would answer ,"fine". I eventually began to wonder if I was giving the wrong answer. She then told me it was part of her job to ask. I was now hanging on to the railings to keep from falling off the treadmill. After another couple of minutes my pulse climbed to 120. After what seemed like hours (it was probably only a couple of minutes) my pulse reached the requisite 134. They needed a sustained 134. Perhaps a minute later I reached that level. They still needed to record another minute of activity at that level. They had commented that it had taken a lot to break past the atenalol barrier. Apparently, atenalol is a drug that reduces the pulse rate. Once they recorded what they needed the treadmill was slowed to a stop. They place a chair on the treadmill for me to collapse into.
Once I recovered sufficiently to stand, they sent me to the caffeteria for coffee and a muffin and instructed me to return in about 40 minutes. When I returned the gamma radiation was again recorded, this time with 3 leads connected so that the recordings could coincide with my heartbeat. In approximately another 15 minutes my test was completed.
I have no report of the results, but was told by the tech that no news is good news.
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