Constitutional Health Network:
Beware: Heart Stress Tests Can Cause
If you’re over “a certain age,” there’s a good chance that at some point your doctor is going to suggest you have a stress test on your heart. For many years stress tests were part of the yearly checkup for a lot of people. And even though the United States Preventive Services Task Force (USPTF) questioned their usefulness clear back in 2012, they’re still routine practice for many doctors.
But their risks might not be so routine. In fact, evidence shows that some types of stress test might bring on the very thing they’re meant to prevent—heart attacks. Here’s what you need to know if your doctor suggests a stress test:

What IS a cardiac stress test, anyway?

The purpose of a cardiac stress tests is, as the name implies, to see how your heart performs under stress. There are two different types of cardiac stress test: exercise stress tests and chemical stress tests. In an exercise stress test, you do some type of exercise—generally walking on a treadmill—to slowly get your heart rate up. While you’re doing this, you’re connected to an EKG machine that measures your heart’s electrical activity. From this, doctors claim they can diagnose blocked or narrowed arteries. They also say they can predict your risk of heart attack.
So far, so good, right? We’d all like to know if we’re likely to have a heart attack ahead of time. But from the available evidence, it appears that exercise stress tests really aren’t very good at predicting who’s going to have a heart attack. And although they may allow doctors to diagnose blockages, research tells us that we may be looking at the problem wrong.
Conventional wisdom has always claimed that most heart attacks happen because a vessel has become blocked by plaque over time. However, we now know that in this case, your body quite often re-routes the blood supply around the blockage—it actually grows new blood vessels and creates its own natural heart bypass.
Newer schools of thought propose that instead what happens in most cases is that the plaque ruptures. When this occurs, your body frantically tries to repair the damaged area, creating a blood clot…which then causes a heart attack.
Whatever the underlying reason, it’s clear that people at low risk for heart problems simply don’t benefit from stress testing. And more than that, it may lead to the dreaded chain reaction of more unnecessary tests, overdiagnosis, and overtreatment. The USPTF gives cardiac stress testing in low-risk people a grade of “D,” meaning they find it useless. And even in moderate to high-risk cases, they say there’s no clear evidence that it’s helpful.
Chemical stress tests, however, are another story. During a chemical stress test, you don’t exercise. The “stress” is all created with drugs—and the FDA says that these drugs can sometimes provoke a heart attack that wouldn’t have happened otherwise.

This test can starve your heart of oxygen

Chemical stress tests are generally used when you’re physically unable to exercise. Maybe you have back trouble. Maybe you’ve had a previous stroke. Maybe you have arthritis in your knees and trotting along a treadmill just isn’t feasible. There are a variety of things that might keep you from attempting an exercise stress test, and in these cases doctors do what they usually do when they need to feel like they’re doing something: they turn to drugs.
In a chemical stress test, you’re still hooked up to an EKG. Since you’re lying still instead of standing up and moving, you might also have what’s called an echocardiogram, which basically uses ultrasound to look at your heart while it’s working hard and see if and where problems occur. You’re hooked up to an IV and given drugs that make your heart work harder.
And this is where the problem happens.
Lexiscan and Adenoscan are the brand names of the drugs regadenoson and adenosine. These drugs dilate the arteries of your heart. Dilating the arteries increases blood flow, making your heart work harder to pump it. Theoretically, this should allow doctors to see which vessels aren’t allowing enough blood flow.
In practice, what can happen is that the blood will take the path or least resistance and flow through the widest-opened arteries first. This means is that if you do have partially blocked arteries, the parts of your heart served by them may be starved of blood—and thus oxygen—causing heart attack and death. Other possible severe side effects include:
Cardiac arrest (your heart suddenly stops beating).
  • Atrial fibrillation.
  • Heart block (where your heart stops conducting electricity properly, and might even stop.)
  • Dangerously high blood pressure.
  • Dangerously low blood pressure.
  • Stroke.
  • Seizures.
  • Respiratory arrest (where you stop breathing.)
  • And of course that’s on top of a host of “minor” side effects.
These drugs have always carried a warning about the potential to cause heart attacks. But during “post-marketing studies”—that is, after testing them on unsuspecting human guinea pigs after FDA rubber stamping—it became clear that this was a deadlier problem than first suspected. The FDA slapped a sterner warning on the drugs in 2013, advising against using them in “people with symptoms of cardiac instability.” They also recommended having cardiac resuscitation equipment on hand when they’re used.
This is what FDA considers “safe and effective,” folks.

First, do no harm…

Do no harm. This is supposed to be a doctor’s prime directive. Not “cure what you can,” or “make people feel better,” but do no harm. And yet, “medicine” is filled with treatments and drugs that have the potential to do great harm and even cause death. It’s not the exception but the norm.
In some cases, the risk of harm may be outweighed by the possibility for good, true—but only in the direst circumstances. And the decision should be up to you, the person risking harm. You should be fully informed of any and all possible dangers, so that you can make a truly informed decision.
That’s not usually the case with stress tests. And here’s the truth: stress tests make money. And the other, often totally unnecessary “interventions” they can lead to—tests, treatments—make even more money. So if you don’t have any symptoms of heart disease, say no to stress testing. And if you do, think long and hard before you agree to a test. The risks are serious. The benefits—even according to the USPTF—unproven. If your doctor recommends a stress test, remember: YOU are in charge. Inform yourself. Make an educated decision. And say no to drug-induced stress testing. 
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