Heart Health Archive

A simple treatment that involves nothing more than a standard blood pressure cuff could protect heart muscle during a heart attack or improve the outcome of bypass surgery or artery-opening angioplasty. The procedure, called remote ischemic preconditioning, works like this: An emergency medical technician or doctor inflates a blood pressure cuff over the upper arm for five minutes, cutting off blood flow to the arm. He or she releases the pressure, restoring blood flow, then repeats the pressure on–pressure off cycle a few more times. This stress causes the body to release chemical messengers that prepare heart cells to withstand both a period of low oxygen supply and the restoration of blood flow — just what they experience during a heart attack or angioplasty.

Early work on the phenomenon of remote ischemic preconditioning in the laboratory and in animals has led to its application in humans. In a British study, remote ischemic preconditioning improved the results of angioplasty (Circulation, Feb. 17, 2009). In a Danish study, it limited the amount of damage caused by a heart attack (Lancet, Feb. 27, 2010). Clinical trials are under way to confirm these findings and perhaps extend remote ischemic preconditioning to other situations, such as heart transplantation or activities that cause chest pain (angina).

The phrase "exercise in bed" conjures images of sex, a fine way to engage in a little physical activity. Miami-based Non-Invasive Monitoring Systems has a different idea, called whole-body periodic acceleration, that may help people who can't exercise in traditional ways.

Instead of moving yourself, whole-body periodic acceleration moves you — shakes you, really — using a special bed called the Exer-Rest that moves back and forth in the head-to-foot direction 140 times a minute. Your feet are strapped firmly to the foot of the bed, so you move with it. This motion mimics the effect of exercise on the arteries as they experience faster, stronger, quicker pulses of blood. Both exercise and whole-body periodic acceleration stimulate the inner lining of blood vessels to release nitric oxide, which tells blood vessels to relax. This improves blood flow throughout the body.

Imagine a legion of microscopic healers patrolling the bloodstream to find and fix injured artery walls. That's the idea behind tiny drug-carrying particles called nanoburrs that have been developed by a team from the Massachusetts Institute of Technology and Harvard Medical School.

Nanoburrs are spheres 60 billionths of a meter (60 nanometers) in diameter. Thousands of them could sit on the period at the end of this sentence. Each has an inner core containing a drug linked to a slowly degradable polymer known as polyethylene glycol. The core is surrounded by a single layer of fat derived from soybeans. The outer wall is another polymer that protects the particle as it travels through the bloodstream. Coating the outer wall are protein fragments that resemble burrs, the hooks that bristle around the outside of certain seeds. In this case, the researchers created burrs that stuck to proteins found in the lining of blood vessels. In a healthy artery, these proteins are hidden by other tissues. In an injured artery, they are exposed to nanoburrs circulating through the bloodstream.

For some people with hypertension, exercise, diet, and three or four pills aren't enough to bring blood pressure under control. A pacemaker-like device called the Rheos system, made by Minneapolis-based CVRx, could someday offer extra help for fighting resistant hypertension.

The device works with the body's baroreceptors. These are sensors that continually monitor blood pressure from their posts on each carotid artery in the neck. When blood pressure rises, the baroreceptors send messages to the brain. It responds by sending signals that lower blood pressure. The opposite happens when the baroreceptors and brain detect low blood pressure.

Implantable cardioverter-defibrillators (ICDs) are small devices that detect potentially deadly heart rhythms, stop them with an electric shock, and restore a normal heart rhythm. Although ICDs are generally implanted in older people who have survived a heart attack, another use is in younger people whose seemingly healthy hearts lapse into the fast or erratic rhythms known as ventricular tachycardia and ventricular fibrillation.

Traditional ICDs are connected to the heart via thin wires called leads (pronounced leeds) placed through a large vein and then into the heart. Placing the leads through the vein is one of the trickiest parts of the procedure, and leads sometimes fail.

High-density lipoproteins (HDL) protect the heart and arteries by removing cholesterol lodged in artery walls and riding through the bloodstream inside of low-density lipoproteins (LDL). Here's a novel way to amplify HDL's cholesterol-busting activity: Take some blood from a person. Extract the HDL. Use a process called delipidation to remove cholesterol and other fats (lipids) from the HDL. Then put the defatted HDL particles back into the bloodstream. This seems to turbocharge HDL and make it work even more aggressively against cholesterol.

In the first clinical trial of HDL delipidation in humans, the procedure was safe and effective. Treated HDL caused cholesterol-filled plaque to shrink more than did untreated HDL (Journal of the American College of Cardiology, June 15, 2010). The trial was too small and didn't last nearly long enough to see if this prevented future heart attacks or improved survival.

Q. I have had a leaking aortic valve for many years. I get an echocardiogram every six months. After the latest one, my doctor told me that my heart was enlarging and asked me repeatedly whether I was getting short of breath with exercise. I told him that sure, I get tired, but it isn't like I am breathing hard while sitting still. Now he wants me to have surgery to replace the valve. Should I do this at age 68?

A. You have been getting exactly the right attention for what is called aortic regurgitation. This is the backflow of some blood into your left ventricle with each heartbeat, instead of it all going into your aorta.

Q. When someone has pneumonia, is it common for the heart rate to fluctuate wildly?

A. Any significant lung disease can increase the heart rate. The stress of being sick causes surges in adrenaline levels, which make the heart accelerate. Lower oxygen levels in the blood also make the heart beat faster. In addition, pneumonia can push the heart into abnormal fast rhythms, such as atrial fibrillation (an irregular rhythm in which different parts of the atrium chaotically fire off electronic signals) or atrial tachycardia or flutter (regular rhythms at heart rates as high as 150 beats per minute or more). These abnormalities may appear because higher pressures in the blood vessels of the lung cause the right side of the heart to dilate, which can throw off the heart's electrical system.

Q. My daughter gave me a pedometer and told me to walk 10,000 steps a day. When I wore it for a while, I realized I was taking only about 3,000 steps a day. Is 10,000 a realistic number for someone my age (70 years)?

A. If you are reasonably healthy, 10,000 steps a day is a good goal for you. It is the equivalent of walking two to three miles per day. You can cover this distance with a walk of 45 minutes or so, and get in your 10,000 steps even if you do nothing else for the rest of the day. Ten thousand steps a day may not be feasible if you have arthritis, heart failure, or other health issues.

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