How the heart handles anger seems to predict who's at risk for a life-threatening irregular heartbeat.
Negative emotions like hostility and depression have long been considered risks for developing heart disease, and deaths from cardiac arrest rise after disasters such as earthquakes.
But research released Monday goes a step farther, uncovering a telltale pattern in the EKGs of certain heart patients when they merely recall a maddening event - an anger spike that foretold bad news.
In already vulnerable people, "anger causes electrical changes in the heart," said Dr. Rachel Lampert, a Yale University cardiologist who led the work. When that happens even in the doctor's office, "that means they're more likely to have arrhythmias when they go out in real life."
At issue is cardiac arrest, when the heart's electrical system goes haywire and heartbeat abruptly stops. Survival requires a fast electrical shock from a device called a defibrillator.
To track anger's effect, Lampert gave EKGs to 62 patients who had defibrillators implanted in their chests because of preexisting heart disease. When they recounted something that had made them angry, some patients experienced beat-to-beat EKG alterations that were similar to irregular heartbeat-predicting alterations that doctors can spot during treadmill testing.
In other words, the emotional stress was producing a red flag like physical stress can. But it did so without causing the jump in heart rate that exercise does, suggesting anger's Adrenalin rush may act directly on heart cells.
The result: People whose EKGs showed a big anger spike were 10 times more likely to have their defibrillators fire a lifesaving shock in the next three years than similarly ill patients whose hearts didn't react to anger, Lampert reported in the Journal of the American College of Cardiology.
Next she's studying whether anger-reducing techniques might help those high-risk patients avoid irregular heartbeats.
Don't race out for an EKG. Nobody knows if anger has a similar electrical effect in people whose hearts aren't already diseased.
But that question should be studied, said Dr. Nieca Goldberg, a spokeswoman for the American Heart Association who wasn't involved with the research.
There's a clear connection between the heart and the head, that chronic negative emotions are somehow heart-damaging. "But we haven't been able to explain why that happens," said Goldberg, a cardiologist at New York University School of Medicine. "This is a step in the right direction."
The question of the still-healthy aside, this is a small study and researchers must test the anger spike's predictive ability in many more heart patients to be sure of its value.
But if it pans out, the finding could affect a huge population: About 100,000 defibrillators are implanted each year in people at risk of irregular heartbeats because of damage from a survived heart attack, genetic disorders and other conditions. Scientists are searching for ways to tell which patients most need the implants, and the anger spike may offer help.