Simply suggesting that a treatment will ease chest pain may not only dampen the pain, but directly alters heart arteries.
Among 30 patients having a procedure to evaluate their chest pain, researchers found that those who were told they were being given an infusion of a pain-relieving drug did, on average, report a decrease in pain.
The participants showed a measurable change in their heart arteries: a slight but distinct narrowing of the vessels. None of the chest-pain patients actually had heart disease; they were told about the “drug” (which was actually harmless saline) only after testing had shown no blockages in their heart arteries.
The key point is that the power of suggestion created an objective change in the blood vessels, according to Drs. Karin Meissner and Joram Ronel of Technical University Munich in Germany.
In a healthy person who is under stress, the nervous system triggers a widening in the blood vessels so that blood circulation increases to meet the body’s needs. When stress fades, the vessels can narrow again.
“When the heart works less,” Meissner and Ronel explained, “there is less need for blood supply, and the vessels will be less dilated than in a stressful situation. This is how we interpret our data.” The situation may be different in a person with heart disease.
How much of that reaction is due to psychological or even biological effects is unclear.
To examine whether there might be placebo effects on the heart arteries, Meissner and Ronel’s team looked at 30 patients who underwent coronary angiography to evaluate chest pain symptoms.
During coronary angiography, a thin tube (catheter) is threaded through a blood vessel into the heart, where a special dye is injected. Using X-rays, doctors can then look for blockages in the heart arteries that may be the source of the chest pain.
The 30 patients were included in this study, only after the test turned up no blockages. While still on the exam table, they were randomly assigned to either a “verbal suggestion” group or a control group.
In both groups, patients received an injection of saline into the catheter. Those in the verbal-suggestion group were told it was a drug that would widen their heart arteries and boost blood flow to the heart. Patients in the control group were told nothing.
On average, the study found, the verbal-suggestion group reported a dip in their chest pain after the procedure, while showing some blood vessel narrowing. The opposite was true in the control group: slightly more pain and a little more vessel dilation.
The researchers say they suspect the pain reduction was an “indirect effect” of the verbal suggestion, but they cannot know for sure whether or to what degree the blood vessel changes might have contributed to it.
Verbal suggestion does have a measurable effect “at the level of the heart” in people with actual heart disease.