Aging heart changes shape, shrinks and loses pumping fu...( Researchers at Johns Hopkins have ev...),Health

Researchers at Johns Hopkins have evidence to explain why the supposedly natural act of aging is by itself a very potent risk factor for life-threatening heart failure.

In a study to be presented Nov. 4 at the American Heart Associations (AHA) annual Scientific Sessions in Orlando, Fla., the Hopkins team analyzed more than a half-dozen measurements of heart structure and pumping function to assess minute changes in the hearts of 5,004 men and women, age 45 to 84, of different ethnic backgrounds and with no existing symptoms of heart disease.

Researchers found that each year as people age, the time it takes for their heart muscles to squeeze and relax grows longer, by 2 percent to 5 percent.

Test results were obtained from study participants who had undergone high-tech magnetic resonance imaging of the heart - tagged MRI - which measures individual muscle segment changes with each heartbeat.

The findings, researchers say, offer insight into the root causes of heart failure. They are especially valuable now as millions of baby boomers in America move into their 60s, a time when most signs and symptoms of heart problems first appear.

Estimates show that more than 5 million Americans have some from of congestive heart failure, marked by symptoms such as shortness of breath and fatigue.

Our results demonstrate just how the heart plays a losing game of catch-up as people age, says Susan Cheng, M.D., a former medicine resident at Hopkins who led the study. Its an amazing piece of the puzzle of heart failure that finally singles out the effects of age over better-known risk factors such as high blood pressure in otherwise healthy people and regardless of race.

We already knew that the heart is constantly trying to adapt to risk factors, but now we know that this task gets more difficult as the heart ages and loses a little bit of its pumping capacity every year, says Cheng, now a cardiolog
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