Q. I may have to undergo bypass surgery and I heard that it can really mess up your mind. Is that true?

If you have coronary bypass surgery, you could suffer from what some in the health care professions call "pump head."During traditional surgery, a patient is put on a heart-lung bypass pump to oxygenate and circulate blood. This machine may create clots that could harm the brain. In addition, a surgeon handling the aorta the main heart artery can free bits of accumulated plaque and they can block blood vessels in the brain.Some patients report a memory loss. Or, they say they are confused. Some feel that they just aren't as mentally sharp as they had been. These side effects seem to be more common among people who are older, drink too much or suffer from high blood pressure or lung disease.But there's a lot of disagreement among experts over the entire subject of the mental effects of bypass surgery.One study indicated that only half of those undergoing bypass surgery developed memory or thinking problems within days after the operation, and that these problems continued for five years. However, other researchers found that mental deficiencies are common after bypass surgery, but that most people recuperate in three to 12 weeks.The pump-head phenomenon led to the development of "beating-heart bypass." It's done without using a heart-lung machine. About one in five bypass operations is now done with a beating heart.In a bypass, an incision is made down the center of the chest to expose the heart. The surgeon takes a section of healthy blood vessel, often from inside the chest wall or from the lower leg, and attaches the ends above and below the blocked artery so that blood flow is diverted around the narrowed portion of the diseased artery. This eases angina, the chest pain that comes when there is an insufficient supply of oxygenated blood.Because the heart beats constantly, it needs a steady flow of fuel. If a fuel shortage is serious, you have a heart attack and muscle begins to die. Heart attack is known officially as "myocardial infarction."The surgery usually takes between three and six hours. On average, surgeons repair two to four coronary arteries. After surgery, patients spend a day or two in the intensive care unit. Recovery takes six to 12 weeks.About half a million Americans a year have coronary bypass surgery. For every 100 Americans who undergo it, one to two die within a month and two to three have a stroke. The long-term results of the surgery are excellent.Among the techniques in development is minimally invasive heart surgery which uses smaller incisions (about three inches) and has many benefits. It may be an option for some patients.If you would like to ask a question, write to

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