A Negative Stress Test
(From 2010, an example of “follow the terrain, not the map”)
Doris Delaney came from the next town. She had just turned sixty and she was worried. For two years she had suffered from chest pain after hard physical work and for the past month her attacks had been a little more frequent.
Her father had died from a heart attack at age 47. Her two brothers had bypass operations before age fifty. Her blood pressure was higher than ideal, even on medication. I flipped through the medical records that had come over on the fax machine and saw that her last LDL cholesterol, on medication, was too high for a high-risk patient.
“I looked on the Internet and I talked to my sister, who is a nurse in Houston. I think I’ve got angina and I’m worried I’ve got a blockage in one of my coronary arteries”, she said in her thick Texas accent.
I found a two-year-old stress test among the faxed pages and mumbled “I see you had a stress test a while back”.
“Yes, and the lady doctor who gave me the stress test told me to go home and take it really easy until I saw my Family Doctor, but he said the test came out okay”, she explained.
The first page of the stress test report was the interpretation of the Sestamibi®, or nuclear scan, where a radioactive tracer injected into the bloodstream shows how evenly the blood is distributed between various parts of the heart muscle at rest and with exercise. “Probably normal” was the conclusion rendered by the offsite cardiologist who interpreted the images.
The second page was the report of what the physician saw when Doris did her treadmill exercise test. It said she had chest pain for several minutes at the end of the test and changes on her electrocardiogram that were fairly typical for ischemia, decreased blood flow to the heart muscle.
“I know what happened”, I told her.
“A hundred years ago we would diagnose somebody with heart disease by listening to their story. Someone with your symptoms was said to have angina pectoris”, I explained.
“When I was in medical school we did EKG stress tests, and they were pretty good at identifying patients with partially blocked arteries. The EKG waveform changes when the heart muscle is stressed, because electricity travels differently through it.
The modern nuclear scan measures something a little different, not whether the muscle is feeling the lack of blood flow but how much blood we see in the picture going to each part of the heart. We think the nuclear test is more sensitive than the EKG, but I don’t know that it always is.
In your case you have symptoms that are very suspicious for having blocked arteries, and one part of your stress test was abnormal. Now you are having chest pain more often, and I want you to see a cardiologist as soon as possible. I think they will want to do a catheterization to look at your coronary arteries.
Today I need to give you a prescription for nitroglycerin, change your cholesterol medication and start you on one more blood pressure medication. These three things can make a difference right away.”
I had her wait in the room for a few minutes while I called the cardiology office at Cityside Hospital and spoke with Dr. Bronwen Wilkes about getting a fast-track consultation. It’s all set; her appointment is Monday.