Haven’t most of us seen this on TV: the lion chasing the gazelle across the African plains? The gazelle is running for its life. We know this as “fight or flight,” and clearly the gazelle has chosen flight. In a much less dramatic way, our bodies demonstrate this same “fight or flight” reaction with high blood pressure.
According to David Brown M.D., a cardiologist on the medical staff at The Heart Hospital Baylor Plano, the sympathetic nerve between the brain and the kidneys can go into “overdrive.” Through this nerve pathway, the kidney sends signal to the brain telling it what is going on and what to do. If those signals ramp up too much, Dr. Brown told Ivanhoe Broadcast News, the result is hypertension.
This is important because there are a billion people in the world with hypertension, or high blood pressure, according to Dr. Brown. “For every 10mmHg of blood pressure increase, the number of heart attacks doubles and strokes double,” Dr. Brown told Ivanhoe.
Some individuals with hypertension take as many as four or five medications, and still can’t significantly lower their blood pressure. Dr. Brown and other physicians around the country are part of a research study looking at renal denervation as a new option to control high blood pressure. After the FDA reviews these study results, physicians may have a new tool to treat uncontrolled hypertension.
Renal denervation disrupts the nerve impulse going back and forth between the kidneys and the brain. Physicians first did this as a surgical procedure in the 1940s and 1950s. Now, thanks to new technology, the procedure can be done using minimally invasive techniques.
Again, Dr. Brown explains the new procedure. “We put a needle in the femoral artery in your groin. Then we can put wires, catheters and balloons in there. We go up and we take some pictures of the kidney arteries. It tells us the size of the arteries, where they branch and what they look like.”
“We are looking to guarantee the safety of the procedure to follow those pictures with an electrode-tipped catheter. It is a catheter with electricity we can put in the right spot in the artery. With a low radiofrequency transmission, lightly burn the nerves, and ablate them or knock them out. If we do that, we can change some of that feedback that is going between the kidneys and brain.”
Drs. David L. Brown and Scott Biederman, The Heart Hospital Baylor Plano, discuss hypertension and renal denervation in the video link that follows. Dr. James W. Choi on the medical staff at Baylor Heart and Vascular Hospital is also a study investigator.