Lightheadedness Upon Standing Could Signal Heart Risk
MONDAY March 19, 2012 -- If your blood pressure drops suddenly when you stand up, leaving you feeling lightheaded or woozy, you may be at greater risk for developing heart failure, a new study suggests.
This condition is known as orthostatic hypotension. According to the study, people with orthostatic hypotension were 54 percent more likely to develop heart failure than their counterparts who did not develop low blood pressure upon standing. This risk was reduced to 34 percent when the researchers teased out those who also had high blood pressure.
"Multiple risk factors can increase a person's risk for developing heart failure, including high blood pressure, coronary heart disease and diabetes," explained study author Dr. Christine DeLong Jones, a preventive medicine resident at the University of North Carolina at Chapel Hill. "Orthostatic hypotension may also increase this risk."
Heart failure occurs when the heart can no longer pump strongly enough for blood to the reach the rest of the body. About 5.7 million people in the United States have heart failure, and about 300,000 people die from it each year, according to the U.S. National Heart, Lung and Blood Institute.
Exactly how orthostatic hypotension could lead to heart failure is not fully understood. "We speculate that orthostatic hypotension and high blood pressure may contribute to the risk of heart failure through a similar pathway, such as through high blood pressure that happens primarily when a person is laying down," she added.
For the new study, researchers looked at more than 12,000 people between the ages of 45 and 64 from four U.S. counties. Close to 11 percent of people who developed heart failure during about 17.5 years of follow-up had orthostatic hypotension at the start of the study, compared with only 4 percent of those who did not go on to develop heart failure. This link was most pronounced among people aged 45 to 55, according to the findings, published March 19 in Hypertension.
To test for orthostatic hypotension, your doctor will measure your blood pressure while lying down and shortly after standing up. Orthostatic hypotension is defined as a drop of 20 mm Hg or more in systolic (the top number) blood pressure or a decrease of 10 mm Hg or more in diastolic (bottom number) blood pressure upon standing.
Some people with orthostatic hypotension might not have symptoms and may not require treatment. Others may experience dizziness, and others may even pass out, Jones said. "If one passes out or has severe dizziness, they should see a provider urgently."
People with orthostatic hypotension who also have high blood pressure should take steps to control blood pressure, and make sure their heart is healthy, she said.
The study authors speculated that orthostatic hypotension might be an indicator of early atherosclerosis -- a buildup of plaque in the arteries -- brought on by high blood pressure.
However, the study does not show that orthostatic hypotension causes heart failure, merely an association between the two.
Dr. Robert Myerburg, a professor of cardiology at the University of Miami Miller School of Medicine, said it is way too premature to say that orthostatic hypotension is a risk factor for heart failure based on this study.
"Orthostatic hypotension can cause unpleasant symptoms and if they lead to loss of consciousness or near loss of consciousness, it can lead to accidents, but this is not something that will lead to cardiac arrest," he said. His advice is to drink plenty of fluid if you have low blood pressure upon standing. "If it doesn't bother you or cause any significant symptoms, you don't have to treat it," he said.
Dr. Stephen Green, chief of cardiology at North Shore University Hospital in Manhasset, N.Y., agreed. "If you get lightheaded, see your doctor and they should see if you have orthostatic blood pressure, which is a common source of lightheadedness or dizziness when you change positions," he said.
"It doesn't mean you will die of heart failure if you have it, but over time, we can keep an eye on any signs or symptoms for heart failure," Green added.
Dr. Tara Narula, a cardiologist at Lenox Hill Hospital in New York City, said that anything that helps diagnose heart failure earlier could be beneficial. "This is an interesting paper, and if orthostatic hypotension proves to be a cause or leads to heart failure in future studies, we could possible identify heart failure earlier than we can now."
Learn more about heart failure and how to treat it at the U.S. National Institutes of Health.
Posted: March 2012