Published by
Stanford Medicine


Cardiovascular Medicine

Cardiovascular Medicine, Nutrition, Science

What’s not to love? Chocolate’s feel-good chemicals

Cabdury2Spring is here and symbols of new life abound. If Cadbury Cream Eggs (yes, gross, but I love them anyway) and Mini Eggs on drugstore shelves have you, too, thinking about chocolate, check out this piece in the Washington Post on the history and chemistry of the “feel-good” components of the stuff, including “the world’s most widely consumed psychoactive drug,” caffeine.

Chemist Simon Cotton, PhD, writes:

Another chocolate molecule believed to be important was discovered less than 20 years ago: anandamide. This binds to receptors in the brain known as cannabinoid receptors. These receptors were originally found to be sensitive to the most important psychoactive molecule in cannabis, Δ9-THC. Likewise, anandamide and similar molecules found in chocolate are also thought to affect mood.

Phenylethylamine, another family of chemicals, is found in chocolate in very small amounts. It is a naturally occurring substance with a structure that is closely related to synthetic amphetamines, which of course, are also stimulants. It is often said that our brain produces phenylethylamine when we fall in love. It acts by producing endorphins, the brain’s natural “feel-good” molecules. The bad news, however, is that eating chocolate is probably not the best way of getting our hands on phenylethylamine as enzymes in our liver degrade it before it can reach the brain.

There are other molecules in chocolate – especially in dark chocolate – such as flavonoids, which some scientists think may help improve cardiovascular health. But chocolate manufacturers have been known to remove bitter flavanols from dark chocolate.

One last feel-good factor, which isn’t a molecule: the melt-in-your mouth sensation. The fatty triglycerides in cocoa butter can stack together in six different ways, each resulting in a different melting point. Only one of these forms has the right melting point of about 34 degrees, so that it “melts in your mouth, not in your hand.” Getting the chocolate to crystallize to give this form is the product of very careful chocolate engineering.

I’m curious to know what kinds of chemicals give the sugary “whites” and “yolks” of the cream eggs their appeal, though maybe it’s better kept a foil-wrapped secret.

Previously: When caffeine dependence affects quality of lifeDo you (heart) chocolate? Evaluating the cocoa “prescription” for cardiac health and Mapping the DNA of wild strawberries and fine chocolate
Photo by Joel Kramer

Cardiovascular Medicine, In the News, Stanford News, Surgery

Looking at aortic valve replacement without open-heart surgery

SM heart imageSome patients with aortic stenosis undergo open-heart surgery to replace a constricted heart valve in an attempt to stave off heart failure. But others, such as elderly adults, aren’t candidates for this type of surgery. In 2011, the FDA approved a non-surgical alternative procedure called TAVR, or transcatheter aortic valve replacement, but the new method, as discussed in the New York Times earlier this month, also carries certain risks.

In the current issue of Stanford Medicine magazine, my colleague Tracie White digs into the surgery-or-TAVR debate and follows the story of one aortic stenosis patient who was treated by the newer method. Maryann Casey, at 62, is younger and healthier than the average TAVR candidate, but she had faced an increased risk for complications during open-heart surgery because of radiation treatment for breast cancer decades ago.

From the magazine piece:

Casey was lucky. Her Stanford oncologist, Frank Stockdale, MD, PhD, the Maureen Lyles D’Amrogio Professor of Medicine Emeritus, was well-informed about treatment options for aortic stenosis, a calcification of the heart valve. This new nonsurgical approach to valve replacement involves placing an artificial heart valve, made of cow tissue supported by a stainless steel mesh frame, inside the damaged valve. Referred to as “transcatheter aortic valve replacement” or TAVR, the procedure is designed for patients with severe, symptomatic aortic stenosis who have health conditions that make the preferred treatment, open-heart surgery, very high risk.

On Oct. 16, 2012, Casey became one of the more than 120 patients that year at Stanford to undergo the TAVR procedure. The first catheter-based aortic valve transplant was in 2002 in France. It has been approved for use for the past six years in 40 other countries including most of Europe, with a total of 45,000 procedures conducted worldwide.

In the United States, institutions such as Stanford, the Cleveland Clinic, Columbia University and the University of Pennsylvania have been leaders in introducing the new procedure and determining its effectiveness through the clinical trials.

Careful patient selection is key to the successful use of the procedure, says [D. Craig Miller, MD, the Doelger Professor of Cardiovascular Surgery], and that sometimes means not recommending TAVR for a patient who is too old or too sick with other illnesses to benefit from the device.

“That’s a very sobering point,” says surgeon Miller. For patients who are too old or ill, undergoing the procedure may not increase their quality of life or life expectancy; Miller says that the boundary line between TAVR “utility and futility” is still being defined.

Previously: Mysteries of the heart: Stanford Medicine magazine answers cardiovascular questionsAsk Stanford Med: Answers to your questions about heart health and cardiovascular research and Major advancement for once inoperable ailing heart valves
Art, which originally appeared in Stanford Medicine, by Pixologicstudio

Cardiovascular Medicine, Women's Health

Study shows many women have a limited knowledge of stroke warning signs

Study shows many women have a limited knowledge of stroke warning signs

woman_heartMore than 795,000 people in the United States have a stroke each year, and about 60 percent of stroke deaths occur in women. But despite this, and the fact that stroke affects more women than men, a new survey conducted by the American Heart Association/American Stroke Association shows that women are largely unfamiliar with the warning signs of stroke. Study researchers said the findings, which are based on a 2012 phone survey of 1,205 women in the United States, are a “significant barrier to reducing death and disability related to stroke.”

According to a release, findings included:

  • More than half (51 percent) of the women identified sudden weakness or numbness on one side of the face, arms or legs as a warning sign of a stroke.
  • Less than half (44 percent) identified difficulty speaking or garbled speech as a warning sign.

Less than a fourth identified other signs of a stroke, including:

  • sudden severe headache (23 percent);
  • unexplained dizziness (20 percent); and
  • sudden vision loss (18 percent).

The associations have developed the acronym F.A.S.T. to help people identify and respond to signs of stroke. It stands for face drooping. arm weakness, speech difficulty and time to call 9-1-1.

Previously: Heart attacks and chest pain: Understanding the signs in young women, Are young adults in denial about how lifestyle choices affect their health? and Gap exists in women’s knowledge of heart disease
Photo by Nicola Jones

Cardiovascular Medicine, Imaging

A microscopic view of the calcification of heart tissue

A microscopic view of the calcification of heart tissue


Aortic valve calcification, which can be an early sign of heart disease, occurs when calcium deposits form on the aortic valve in the heart causing the soft tissue to harden. This striking image from the Wellcome Images Awards 2014 offers a microscopic view of clumps of calcium salts building up on the heart valve. A description on the winners’ photo gallery offers more detail about how it was created:

This image was produced using a type of scanning electron microscopy called density-dependent colour scanning electron microscopy. In this method, images are taken of a sample using two different detectors, one which records topographical information about the surface of the sample and one which records information about its density. A different colour is assigned to each and the images are then superimposed to produce a composite image like the one you see here. In this particular image, the orange colour identifies denser material (calcified material composed of calcium phosphate), while structures that appear in green are less dense (corresponding to the organic component of the tissue).

Previously: Big hand, beautiful biofilms, Image of the Week: One of 2013′s “coolest” microscopic images, Image of the Week: Microscopic view of lung surfactant and Touring the microscopic worlds of the human body
Photo by Sergio Bertazzo, Wellcome Images

Cardiovascular Medicine, Medicine and Society, Stanford News

A heartfelt story about a young aspiring doc and a famous transplant surgeon

ShumwayFor anyone who had a childhood passion (medical or otherwise), take a few minutes to read a terrific narrative piece in the current issue of Stanford Medicine magazine.

The story begins in the archives right here at the School of Medicine’s communication office and describes a true tale of an 11-year-old boy who, inspired to begin practicing medicine, wrote to heart-transplant pioneer Norman Shumway, MD, for surgical advice. Intern Jerome Macalma was scanning documents when he came across the handwritten note, and he used Facebook to solve the modern-day mystery of the letter-writer’s identity.

It turns out that once-aspiring doctor Robert Wise had become a real one. In the piece, Wise, MD, fleshes out details of the letter’s story and his journey to become an emergency medicine physician with a clinical interest in cardiovascular emergencies. I’ll save the rest for you.

Happy reading!

Previously: Mysteries of the heart: Stanford Medicine magazine answers cardiovascular questionsMiddle school students get brainy and Doc McStuffins: A pint-sized inspiration for girls of all colors
Related: Norman Shumway, heart transplantation pioneer, dies at 83

Cardiovascular Medicine, Stanford News, Videos

Stanford researchers ride the ‘vomit comet’ to test device for monitoring astronauts’ heart function

Stanford researchers ride the 'vomit comet' to test device for monitoring astronauts' heart function

When astronauts travel into space, their heart muscles don’t have to work as hard to circulate blood because of the lack of gravity. Past research has shown that half of astronauts on missions lasting two weeks or less and nearly all of those who spend four to six months in space suffer from hypotension, or abnormally low blood pressure.

To improve astronaut safety, Stanford researchers have developed a simple device that provides high-fidelity measurements of astronauts’ cardiovascular performance. As reported in a Stanford Report story, the project involved re-engineering a digital bathroom scale so that it is capable of determining cardiac output even in microgravity. Bjorn Carey writes:

After more than a dozen publications on the technology and its performance in human tests, the researchers found that the ballistocardiograph measured by their modified scale could measure cardiovascular activity in equal or better resolution than other clinical mechanical monitoring devices.

In a single 10-second measurement, the scale can glean enough data from a patient to assess his or her cardiovascular risks. [Richard Wiard, a bioengineering doctoral candidate] said that the scale does this with greater accuracy than the standard assessment used today, and also provides a clearer picture of a patient’s (or space-faring astronaut’s) near-term risk.

The above video shows footage from researchers’ ride on what astronauts have affectionately dubbed the “vomit comet,” a fixed-wing airplane that dips and climbs through the air to simulate the feeling of weightlessness.

Previously: Students design special stethoscope for use in space, noisy places, Space: A new frontier for doctors and patients and Fruit flies in space! Researchers hope to learn more about the heart through space-station experiment

Cardiovascular Medicine, Genetics, Health and Fitness, Men's Health, Stanford News

The ultramarathoner’s heart

The ultramarathoner's heart

Nuttall-trail 2-webThe manufacturer’s warranty on the human heart is about 100 years or 2.5 billion beats. But do ultra-long-distance runners void this warranty when they regularly run races of 50 to 100 miles?

This was the question at the top of my mind as I wrote a tall tale about Mike Nuttall, a visionary Silicon Valley product designer and an ultramarathoner with hereditary heart disease, featured in the cardiovascular health issue of Stanford Medicine. In 2010 he had a heart attack and a triple bypass operation. Then he went on to run one of the most challenging races on the planet.

Was this fearlessness or folly?

An ultramarathoner pushes a body to its outer limits. Bones and joints are pounded. Dehydration can upset the electrolyte system, the delicate balance of salts and fluids that regulates heart, nerve and muscle functions. The heart, the ultramarathoner of organs, goes into overdrive for about 24 hours. But above all, an ultramarathon tests the mind, as a runner strives to override the brain’s overwhelming signals of pain and fatigue.

In the story, there are plenty of opinions from friends and heart experts on the wisdom of Nuttall’s post-heart-attack decision. But I guess, in the end, what he did was personal and heartfelt.

Previously: Study reveals initial findings on health of most extreme runners, Euan Ashley, MD, on personalized medicine for heart disease and Mysteries of the heart: Stanford Medicine magazine answers cardiovascular questions
Photo by Bert Keely (Nuttall’s wingman)

Cardiovascular Medicine, Genetics, Research, Stanford News, Stem Cells, Transplants

Stem cell medicine for hearts? Yes, please, says one amazing family

Stem cell medicine for hearts? Yes, please, says one amazing family

SM image of bird and heartRecently, a medical situation with one of my children had me gnawing my fingernails and laying awake at night waiting for scary-sounding test results. Thankfully, my growing anxiety was relieved after several days by a reassuring phone call from our doctor. Unfortunately, the health concerns of the stars of my most recent magazine story - the Bingham family of eastern Oregon – are not so easily dismissed.

Three of the five Bingham children have a heart condition called dilated cardiomyopathy; two of the three (14-year-old Sierra and 10-year-old Lindsey) have already had heart transplants at Lucile Packard Children’s Hospital Stanford. Their parents, Jason and Stacy, were gracious enough to share their family’s story with me for my article in our most recent issue of Stanford Medicine magazine.

Heart transplants are life-saving, but they come with a lifetime of medication and monitoring. Many physicians feel that cardiac medicine is on the cusp of a revolution – one in which the power of stem cells will be harnessed to help hearts heal themselves, or perhaps even to grow new, perfectly matched organs for transplant. The California Institute for Regenerative Medicine has awarded more than $120 million to pursue potential therapies. No matter how fast any advances occur, however, they can’t come soon enough for the Bingham parents, who are now anxiously monitoring 5-year-old Gage’s battle with the same disease that led to his sisters’ transplants.

At the same time, physicians at the Stanford Center for Inherited Cardiovascular Disease are searching to find the (presumably) genetic cause for the Bingham family’s heart problems through gene sequencing while researchers in the laboratory of Stanford cardiologist and director of the Stanford Cardiovascular Institute Joseph Wu, MD, PhD, work to create induced pluripotent stem cells from the family to better understand the molecular basis of their illnesses.

I’ve been thinking a lot about Jason and Stacy this past week while I faced my own fears for my daughter. I cannot comprehend how strong they have to be for their children. And, although I work daily with many amazing doctors and researchers, I have to say that Jason and Stacy (and other parents like them) are my true heroes.

Previously: Mysteries of the heart: Stanford Medicine magazine answers cardiovascular questions, At new Stanford center, revealing dangerous secrets of the heart and Packard Children’s heart transplant family featured tonight on Dateline and
Illustration, which originally appeared in Stanford Medicine, courtesy of Jason Holley

Cardiovascular Medicine, Patient Care, Stanford News

How a low-sodium diet increased one heart patient’s quality of life

How a low-sodium diet increased one heart patient's quality of life

carrotscelery“The secret ingredient is salt,” said a plastic-figurine Marge Simpson at the push of a button in my mom’s Simpsons living-room diorama. (Marge was holding a tray of cookies she presumably had just made.) But for some congestive heart failure patients, the secret to recovery is not-salt.

I thought of Marge when reading a heartening piece in the recent issue of Inside Stanford Medicine. It tells the story of how patient Bruce Simon, after recovering from a heart attack and cardiothoracic surgery, adopted a low-sodium diet according to his doctors’ recommendations and was able to avoid needing a heart transplant. By modifying his lifestyle as part of his health-improvement regimen he went from sleeping upright and wearing an oxygen mask to being able to walk two miles on a treadmill without becoming short of breath.

From the piece:

“A lot of people with heart failure come to a cardiologist’s office and expect to get medications,” said Simon’s doctor, Dipanjan Banerjee, MD, clinical assistant professor of cardiovascular medicine and medical director of Stanford Hospital’s Mechanical Circulatory Support Program. “Probably the most important thing we do in our clinic is focus on lifestyle and dietary changes. The cornerstone of our therapy for our congestive heart failure patients is sodium restriction.”

Simon, who came to Stanford Hospital & Clinics to be evaluated for a heart transplant on the recommendation of his Montana doctors, performed just a little too well on the heart transplant evaluation tests, so Banerjee sat him down to talk about diet. Even though Simon did not have high blood pressure or high cholesterol — two key precursors of coronary artery disease — his heart was stressed by the effort needed to pump accumulated excess fluid. Sodium in excess puts more stress on the heart, Banerjee said, because it causes water retention, making the heart work harder to pump that extra fluid around the body. “For people who don’t have congestive heart failure, reducing sodium is not as important,” Banerjee said. “For a patient with congestive heart failure, low-sodium intake is crucial.”

Rather than prescribe higher doses of diuretics to help rid Simon’s body of excess fluid, Banerjee wanted him to try living by a simple rule that he often prescribes for his patients with heart failure: “Nothing out of a can, nothing out of a bag, nothing out of a box and no processed foods” is how Simon remembers it.

Simon said, “People tell me I don’t even look like the same guy,” he said. “I feel great, and I can do just about anything I want. Eating carrots and celery is a whole lot better than having a heart transplant.”

Previously: Survey shows Americans need a refresher course on heart health“Sodium Girl” on living with a salt-free diet and Tips for avoiding hidden sodium at the supermarket
Photo by Nathan Borror

Applied Biotechnology, Bioengineering, Cardiovascular Medicine, Stanford News, Technology

Heart devices get a mobile makeover

Heart devices get a mobile makeover


Emerging diagnostic heart devices are going mobile. And by leveraging advances in smartphones and sensors, they’re able to perform their functions better, faster and cheaper than traditional heart monitoring equipment.

For example, the CADence, shown above, detects blocked arteries from the surface of the chest by identifying the noisy signals of blood turbulence associated with blockages.

The Zio Patch, on the right, is a sensor that can be worn on the chest for up to 14 days to detect intermittent, irregular heartbeats, called arrhythmias. ZIO-150-90

Both of these amazing devices reveal the mysteries of the heart non invasively, and they provide more potentially life-saving heart data to physicians than conventional equipment.

Yet despite these advantages, adoption into the medical system has been slow.

In the new issue of Stanford Medicine magazine on cardiovascular health, I interview the entrepreneurs behind these inventions — the heart gadgeteers — and let them describe the hurdles that add years to the process of launching new medical devices into the marketplace.

Previously: Mysteries of the heart: Stanford Medicine magazine answers cardiovascular questions, New Johnson & Johnson CEO discusses medical device futures at Stanford eventStanford physician-entrepreneur discusses need to change FDA approval process and Is the United States losing ground as a leader of medical innovation?
Photos courtesy of AUM Cardiovascular, iRhythm Technologies

Stanford Medicine Resources: