Feb. 11, 2002 -- Stick with the program, and eventually your heart will thank you. That's the message from a new study that shows long-term use of drugs designed to lower blood pressure can actually improve the heart's pumping action over time -- even though their immediate effects may not be felt by the user.
It's the first time researchers have documented structural changes in the heart's main pumping chamber, the left ventricle, and improved heart function through the use of blood pressure-lowering (antihypertensive) medications. The study appears in Circulation: Journal of the American Heart Association.
"The new findings suggest that a year or more of treatment with antihypertensive drugs can improve the way the heart's pumping chamber fills with blood, and that improvement may prevent the development of congestive heart failure," says study author Kristian Wachtell, MD, PhD, assistant professor of medicine at Copenhagen County University Hospital in Denmark in a press release.
Heart failure occurs when the heart can't keep up with its workload of pumping and supplying blood to the body. Researchers say people with high blood pressure, or hypertension, are two to three times more likely to develop the condition than those with normal blood pressure.
High blood pressure in adults is defined as having a systolic (top number in a blood pressure reading) of more than 140 millimeters of mercury (mmHg) and/or a diastolic (bottom number) of more than 90 mmHg.
In the study, researchers used echocardiograms (a method of creating images of the heart's structure using ultrasound technology) to measure heart wall thickness and how well the heart's chambers filled with blood, in 728 patients with high blood pressure and enlarged hearts. The patients received one of two blood pressure-reducing drugs -- either Cozaar, or Tenormin (atenolol), a beta-blocker.
After a year, the participants were examined again, and researchers found the treatment reduced blood pressure by an average of 23 mmHg systolic and 11 mmHg diastolic. Heart size was also reduced by an average of 10%, which led to improved blood flow into the heart's main pumping chamber.
At the start of the study, only 15% of the participants had normal blood flow into the left ventricle, but after a year of treatment with blood pressure-lowering medications that number grew to about 26%. In addition, researchers found an improvement in the heart's ability to relax, and stiffness was reduced.
The American Heart Association estimates that as many as 50 million Americans have high blood pressure, and 4.8 million Americans have heart failure. Symptoms of heart failure include fatigue and difficulty breathing.