Type of stress determines how the heart reacts, researchers report.
July 10, 2006 (Press Release) --
An enlarged heart is usually considered a sign of cardiac trouble. But the cause of the enlargement is critical in determining whether there's actual heart disease, researchers are reporting.
In fact, the nature of the stress that created the enlargement is more important than the duration of the stress, according to the researchers.
"We set out to answer a longstanding question in cardiac biology, which is what happens to the heart during periods of stress," said lead researcher Dr. Howard Rockman, a cardiologist at Duke University Medical Center.
The researchers looked at different types of stress, such as stress from exercise, as well as so-called pathological stress that causes damage to the heart. High blood pressure is an example of pathological stress, Rockman said.
Although both types of stress can be severe, the way the heart responds to exercise or high blood pressure is very different, Rockman said. "Exercise is beneficial. The heart adapts in a good way," he said.
Endurance runners have large hearts, Rockman noted, but without damage to the function of the heart. "In contrast, someone with longstanding high blood pressure can develop a dilatated heart and heart failure," he said.
To test the reactions of the heart to these different types of stress, Rockman's team did a series of experiments in mice.
The findings appear in the June 1 issue of the Journal of Clinical Investigation.
The experiments demonstrated that intermittent cardiac stress from high blood pressure starts a series of events that eventually leads to abnormalities in heart muscle cells as well as damage to blood vessels. The researchers also found that these harmful responses can begin before the heart itself begins to get bigger.
Source: http://www.msn.com/
In fact, the nature of the stress that created the enlargement is more important than the duration of the stress, according to the researchers.
"We set out to answer a longstanding question in cardiac biology, which is what happens to the heart during periods of stress," said lead researcher Dr. Howard Rockman, a cardiologist at Duke University Medical Center.
The researchers looked at different types of stress, such as stress from exercise, as well as so-called pathological stress that causes damage to the heart. High blood pressure is an example of pathological stress, Rockman said.
Although both types of stress can be severe, the way the heart responds to exercise or high blood pressure is very different, Rockman said. "Exercise is beneficial. The heart adapts in a good way," he said.
Endurance runners have large hearts, Rockman noted, but without damage to the function of the heart. "In contrast, someone with longstanding high blood pressure can develop a dilatated heart and heart failure," he said.
To test the reactions of the heart to these different types of stress, Rockman's team did a series of experiments in mice.
The findings appear in the June 1 issue of the Journal of Clinical Investigation.
The experiments demonstrated that intermittent cardiac stress from high blood pressure starts a series of events that eventually leads to abnormalities in heart muscle cells as well as damage to blood vessels. The researchers also found that these harmful responses can begin before the heart itself begins to get bigger.
Source: http://www.msn.com/
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