Controlling Your Blood Pressure Archive

What is the test?

People who have leg pain when exercising may need an evaluation to make sure they have normal blood flow through their leg arteries. Normally blood pressure is similar whether it is measured in the legs or in the arms. If blood pressure is lower in the legs, it usually means that cholesterol buildup inside the leg arteries is interfering with circulation. By taking accurate blood pressure measurements at different locations along your legs, your doctors can determine if you have any arterial narrowing and, if so, where.

In order to get accurate blood pressure measurements, your doctor uses a technique called Doppler ultrasound. Doppler ultrasound is a painless way to detect blood flowing through a small artery. It uses sound waves and a type of sonar detection system to make noise when blood flow is detected. For arterial studies of the legs (called segmental Doppler pressures), Doppler ultrasound is used in place of the stethoscope that doctors usually use when taking blood pressures.

In the journals

Need another reason to get your annual flu shot? It could protect you from a fatal heart attack or stroke if you suffer from high blood pressure, according to research presented at a 2019 joint conference of the European Society of Cardiology Congress and the World Congress of Cardiology.

Previous research has found that the inflammation from a flu infection can trigger a heart attack or stroke, and people with high blood pressure are especially at high risk.

Simple breathing techniques may help you to better manage heart-related issues.

Maybe you're already in the habit of taking a deep breath to calm down when you're feeling fed up or frustrated. But a regular practice of focused breathing might offer even bigger rewards.

"Stress directly affects blood flow to the heart muscle, and any technique people can use to lower stress will benefit the heart," says Dr. Kimberly Parks, a cardiologist at Harvard-affiliated Massachusetts General Hospital. Some people turn to yoga, tai chi, or meditation for stress relief. But others aren't interested in trying those techniques. For them, a simple breathing practice may be more appealing, in part because it's easy, it's free, it takes just a few minutes, and it can be done anywhere at any time.

Known as bradycardia, this heart rhythm disorder can cause fatigue, dizziness, and fainting.

The steady beat of your heart depends on a crescent-shaped cluster of cells in the upper right portion of your heart. Called the sinoatrial or sinus node, it emits a tiny jolt of electrical current that triggers the heart to contract and pump blood throughout the body (see illustration). Because the sinus node determines the heart's pace and rhythm, it is sometimes called the body's natural pacemaker.

Just as your skin, joints, and other parts of your body reveal signs of normal wear and tear as you age, so too can the structures inside your heart. "This age-related degeneration can affect the sinoatrial node and other parts of the heart's conduction system," says Dr. Peter Zimetbaum, director of clinical cardiology at Harvard-affiliated Beth Israel Deaconess Medical Center.

Research we're watching

With some smartphones, you can unlock the phone simply by showing your face. One day, a short video of your face may do far more — maybe even measure your blood pressure.

That's the premise of a novel smartphone-based technology described in the August issue of Circulation: Cardiovascular Imaging. For the study, researchers took two-minute videos of 1,328 Chinese and Canadian adults, using an iPhone equipped with transdermal optical imaging. The software measures blood pressure by detecting blood flow changes in a person's face. When compared with readings taken using a traditional blood pressure cuff, the video blood pressure readings were about 95% accurate.

Your blood pressure is one of the best ways to measure overall health and possible risk factors. Do you know your numbers?

There are many important health markers: cholesterol levels, blood sugar levels, weight — to name but a few. But men often fail to use one of the most important: blood pressure.

"Your blood pressure is one of the easiest and simplest measurements and can tell you so much about your current and possible future health," says Dr. Randall Zusman, director of the division of hypertension for Harvard-affiliated Massachusetts General Hospital's Corrigan Minehan Heart Center. "Yet most people don't know their number or check it on a regular basis, so they may not be doing everything they need to lower their risk of a heart attack or stroke."

Research we're watching

Although people tend to focus more on the first number in a blood pressure reading, the second number is also important for predicting heart disease risk. That's according to a study based on 36 million blood pressure readings from more than 1.3 million adults, published in the July 18 New England Journal of Medicine.

Systolic pressure (the first number in a blood pressure reading) measures the force with which the heart pumps blood into the arteries. Diastolic pressure (the second, lower number) reflects the pressure in the arteries when the heart rests between beats. Over eight years, more than 44,000 people in the study had a heart attack or stroke. The risk of those events rose among people with systolic readings of 130 and higher, but also in those with diastolic readings of 80 and higher. The findings are a reminder to pay attention to both numbers in your blood pressure reading, and that for most otherwise healthy people, lower blood pressure is better.

Sodium doesn't affect everyone equally, but there's good reason to stick to moderate amounts in your diet.

On average, Americans eat too much salt — more than a teaspoon and a half a day. Most often it doesn't come out of a shaker, but is hidden in the foods you eat. But is it really bad for your heart to eat too much, or is that just a concern for people with certain risk factors? There's been some debate on this topic, even among members of the scientific community. We asked Nancy Cook, a professor of medicine at Harvard Medical School, for her thoughts on salt — or more precisely, sodium, a mineral that makes up 40% of salt — and how it affects your health and your heart.

Is salt really bad for your heart?

"There is a fairly undisputed effect of sodium on blood pressure," says Cook. The effect is stronger in people with high blood pressure (hypertension), a sustained blood pressure reading of 120/80 or higher. The data for an effect on cardiovascular disease are somewhat more controversial, she says, but in general, the bulk of research does seem to link lower sodium intake with both lower blood pressure and a lower risk of cardiovascular disease.

Nerve damage might be causing everything from low blood pressure to gastrointestinal distress without your knowing it.

Doctors have long known peripheral neuropathy as a nerve condition that causes reduced sensation, tingling, weakness, or pain in the feet and hands. But those symptoms may be just the tip of the iceberg. Doctors are now learning that neuropathy can cause many more problems.

What is peripheral neuropathy?

Peripheral neuropathy refers to damage to the peripheral nerves throughout the body. These nerves carry messages to and from the brain.

News briefs

A study published online June 10, 2019, by Circulation suggests that scaling up three healthy lifestyle changes could increase the life spans of almost 100 million people around the world. Researchers — led by a team from the Harvard T.H. Chan School of Public Health — evaluated global data on death rates, blood pressure levels, the use of blood pressure medications, sodium and trans fat intake, country, age, and gender. They estimated that a worldwide push to lower blood pressure, reduce salt intake by 30%, and eliminate the consumption of trans fat could delay more than 94 million deaths from cardiovascular disease in the next 25 years. More than half of those deaths would be among adults ages 70 or older, and more than half of all deaths would be among men. Regions that would see the most benefit are outside the United States — in East Asia, South Asia, the Pacific, and parts of Africa. But we can all benefit from the three lifestyle changes. Trans fat has already been banned in foods in the United States. But if your blood pressure isn't under control, it's time to talk to your doctor about treatment and to reduce sodium intake to well under 2 grams per day.

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