Women and Cardiovascular Disease from Multiple Perspectives – I

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Three Lectures from Stanford University Medical Center faculty
Moderated by: Hannah Valantine, M.D.
Professor of Medicine, Cardiovascular, and Associate Dean for Diversity and Leadership
Stanford University Medical Center

Moderator’s Overview:
In her opening statement, Dr. Valantine shared the guiding and expansive vision that is the foundation of the program called Women’s Heart Health at Stanford. The program is designed to raise and help to answer one of the most compelling questions of the early 21st century: Is there a difference between men and women regarding heart health, and if so, should we be doing something different? Dr. Valantine reminded the audience that while death rates from heart disease are decreasing in men, they are in fact increasing in women, and it is important to know that women with cardiovascular diseases often arrive in a doctor’s office or emergency room with a different constellation of symptoms than men. This series of three topical lectures presented during one evening, offered an overview of the heart diseases most effecting women, a discussion of the treatments, and updates on the latest news on research at Stanford.

Stanford Health Library can do the searching for you. Send us your medical questions.

For further information about the clinical trials and research being performed at Stanford, please visit the following websites:

Women’s Hearth Health At Stanford:
http://cvi.stanford.edu/womens_heart/

Ten Questions a Woman Should Ask Her Healthcare Provider:
http://www.americanheart.org/presenter.jhtml?identifier=2759

Stanford Hospital & Clinics
www.stanfordhospital.com

American Heart Association (which includes information about women and heart disease)
www.americanheart.org

Abdominal Aortic Aneurysm Disease: The Silent Killer

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Presented by: Ronald L. Dalman, M.D.
Professor of Surgery
Stanford University Medical Center
September 26, 2007

Lecture Overview:
There has been considerable interest recently in public education and screening for Abdominal Aortic Aneurysm (AAA) after a front page Wall Street Journal article about it received the Pulitzer Prize for Health Reporting a few years ago. There are 30,000 deaths in the US each year related to AAA, a condition that years ago claimed the life of Albert Einstein and George C. Scott. AAA occurs when a portion of the aorta becomes worn out due to the loss of elastin, a protein that promotes tension in the skin and blood vessels. The cause of an aneurysm can be genetic but smoking is the single highest risk factor in causing AAA. Dr. Dalman provided a thorough overview of the definition and clinical management for small and large AAA. While there is no clear and well-proven treatment for small AAAs (between 3 and 5.5 cm), there are surgical options for the larger, more worrisome kind of aneurysm (5.5 cm or larger).

Who?

  • AAA is among the top 15 leading causes of death in mature adults
  • 6% of men
  • 1.5 % of women

What and Where?

  • An Abdominal Aortic Aneurysm (AAA) is an enlargement of the aorta. The aorta, which starts in the heart and moves through the left side of the chest, through the diaphragm and into the abdomen, is the largest artery in the body and supplies blood to the entire body.
  • An AAA occurs in the space between the lowest part of the sternum (the blood supply to the kidneys and other organs) and the part of the aorta where it splits into the iliac arteries (supplying blood to the legs).
  • According to Dr. Dalman, there are usually six years between the identification of a 3 cm AAA and the recommendation for surgery.
  • The most common symptom is pain, often confused with back pain.
  • The growth rate is about .4 cm annually, which translates to about two and a half years for an AAA to grow a centimeter.

There are two types of surgeries to treat AAA:

  1. Abdominal aortic aneurysm open repair
    A large incision is made in the abdomen to directly visualize the abdominal aorta and repair the aneurysm. A cylinder-like tube called a graft may be used to repair the aneurysm. Grafts are made of various materials such as Dacron (textile polyester synthetic graft) or polytetrafluoroethylene (PTFE, non-textile synthetic graft). This graft is sewn to the aorta, connecting one end of the aorta at the site of the aneurysm to the other end. The open repair is considered the surgical standard for an abdominal aortic aneurysm repair.
  2. Endovascular aneurysm repair (EVAR)
    EVAR is a procedure that requires only small incisions in the groin along with the use of x-ray guidance and specially-designed instruments to repair the aneurysm. With the use of special endovascular instruments and x-ray images for guidance, a stent-graft is inserted via the femoral artery and advanced up into the aorta to the site of the aneurysm. A stent-graft is a long cylinder-like tube made of thin metal mesh framework (stent), while the graft is made of various materials such as Dacron or polytetrafluoroethylene (PTFE). The graft material may cover the stent. The stent helps to hold the graft open and in place.
    For patient education information and additional information on surgical repair, please visit:
    http://www.vascularweb.org/

When?
AAAs that require treatment are most likely to occur in people over 55. Often an AAA is identified when a patient is screened with ultrasound or CT scan for another condition. People with a family history and with symptoms may be screened at any time depending on a doctor’s recommendation.

Why?
The highest risk factor for AAA is smoking (a risk of 5 on a scale of 1-5) and genetics (a risk of 1.5)

For More Information:

Stanford Health Library can do the searching for you. Send us your medical questions.

Division of Vascular Surgery at Stanford University
http://vascular.stanford.edu/
The Division of Vascular Surgery at Stanford aims to provide a model of clinical and scientific excellence in the diagnosis and treatment of vascular diseases, to deliver the highest quality of care to our patients by a team of dedicated surgeons and nurses, and to achieve these goals within an environment that fosters compassion and respects the humanity of the individual person.

Link to Clinical Trial information at Stanford Medical Center:
Abdominal Aortic Aneurysms: Simple Treatment or Prevention (AAA: STOP)
http://aaastop.stanford.edu/
If you are a patient with a small abdominal aortic aneurysm (<5.5 cm in size) and over the age of 50, you may qualify for participation in the AAA: STOP study. The goal of AAA: STOP is to gather information on AAA risk factors and determine whether an exercise program modifies the progression of AAA disease. Please contact Julie White at Stanford University for more information on this research program by phone at (650) 498-6039 or by email at [email protected].

Medicare AAA Screening Benefit
http://www.vascularweb.org/patients/medicarescreening/index.html
The Screening Abdominal Aortic Aneurysms Very Efficiently (SAAAVE) Act provides for a free, one-time AAA screening as part of the “Welcome to Medicare” physical exam.
Men and women with a family history of AAA and men who have smoked at least 100 cigarettes during their life qualify for the Medicare screening.

Dr. Dalman’s Stanford Profile:
http://med.stanford.edu/profiles/Ronald_Dalman/

Hypertrophic Cardiomyopathy: A Patient Story

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At 18, James Cooper was a disciplined student with a lifelong dream of becoming a firefighter. He was also a competitive basketball player and precisely the picture of good health and fitness that Hypertrophic Cardiomyopathy (HCM) has been known to shatter.

hcm_team.jpg“The first presentation of HCM is often death on the playing field, according to Dr. Euan Ashley, Director of the Stanford Hospital HCM Center. Through a fortunate series of what James’ mother, Paulette Cooper, calls “opportunities to listen,” James’ abnormal EKG test results were eventually sent to the Stanford team who diagnosed James with HCM. Mrs. Cooper then recalled stories about family members who may have had HCM, given their early and sudden deaths.

This disquieting family history, combined with James’ repeatedly abnormal EKG tests, prompted the decision to implant a defibrillator to help prevent his heart from suddenly stopping.

Dr. Ashley says that ending James’ dream of being a firefighter and blocking him from competitive sports were among the hardest decisions he has made. A life-altering diagnosis affects a patient’s entire family.

“Seeing him sitting on the bench was devastating,” Mrs. Cooper recalls. Dr. Ashley says James would plead to be allowed to do some sit ups, or run up the stairs—anything. “He missed the buzz of sports. I understand. I like to play basketball too,” Dr. Ashley said. James now considers Dr. Ashley’s handling of the situation to have been especially helpful. “He never made me feel like he was taking anything away from me,” James says. “He explained everything. He gave me choices.” His mother also is grateful to the Stanford HCM Center for “walking us through everything. We established a relationship with them and any questions we had, we got answers. Having everyone in one place meant a lot to me. They helped put my fears to rest.”

Not long ago, James reflected on why he had wanted to be a firefighter since he was four years old. He had wanted always to be brave and help others. Given that HCM is among the stealthiest of cardiac ailments, he suddenly felt lucky to be alive and have a chance to redirect his goals. He felt a surge of gratitude to family and friends for helping him through the darkest days. He appreciated Dr. Ashley for gently coaching him through a difficult season.

The help he received at Stanford, not only physically, but also emotionally and intellectually, transformed James. Dr. Ashley’s commitment to excellence, compassion and fair play is exactly what James expects of himself and the essence of his career goals. James will soon transfer to UC Santa Cruz, where he plans to major in Health Sciences. And, inspired by a new role model, he hopes to pursue a career in medicine.

Avoiding the Elephant on Your Chest: How to Discuss Cardiac Risk With Your Doctor

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Presented by: Euan Ashley, MD, PhD
Assistant Professor, Cardiovascular Medicine
Stanford University Medical Center

Watch the video

Lecture Overview:

  • Heart disease comes in many forms and variations; blood vessel plaque also has variations
  • The body’s immune system appears to play a role in the buildup of arterial plaque
  • No test yet exists to image the kind of vulnerable plaque buildup that might lead to a heart attack
  • Most of the risk factors for heart disease can be modified with changes to diet, exercise, stress reduction and other lifestyle behaviors

Patient A is in his 40s, overweight and sedentary, and thinks a fast-food burger with the works is a good dinner. Determined to get back into shape, he challenges a junior executive to a game of racquetball. Halfway through, he clutches his chest and is rushed to the hospital with a heart attack.

Patient B is 75, retired, eats well and walks a lot. Heading up a hill, however, she needs to stop for the pain in her chest to abate.

Patient C is fit, eats well, has low blood pressure and exercises regularly. Warming up for his routine one morning, he is rushed to the hospital with a heart attack and a stent is inserted into his blocked artery.

While most people understand the circumstances of the first two patients, the third is the one most people-and physicians-find the most confusing. How can you be perfectly healthy one day and have a heart attack the next? What, if anything, can you do to avert the same fate?

While certain measures can be taken to reduce heart disease risk, medicine is still working to understand the many factors that lead to heart attack and cannot yet perfectly predict who is most susceptible, according to Euan Ashley, MD, PhD, an assistant professor of cardiovascular medicine and director of Stanford Hospital’s Hypertrophic Cardiomyopathy Center.

“Ten years ago, we would refer to the heart and blood vessels as plumbing, and we cardiologists thought of ourselves as plumbers,” said Ashley, who gave a presentation sponsored by the Stanford Health Library on assessing heart attack risk. “The idea was that there were two stages of heart disease: angina, where there is not enough blood circulating to the heart, and heart attack, which is a complete blockage. This turned out to be too simplistic, because, among other reasons, it doesn’t help us explain why seemingly perfectly healthy people die of sudden heart attack.”

Simple plumbing does not fit the evidence, he continued. Angina, the chest pain that occurs when an area of your heart muscle doesn’t get enough blood, does not necessarily lead to heart attack, and many people who have heart attacks do not show symptoms of angina.

“The logic didn’t add up, so we needed a new paradigm,” he said.

Inflammation in the Arteries
Cholesterol is one key factor. Since the fat we eat doesn’t dissolve in the blood, the body must find ways to package and store it using lipoproteins of different sizes. When high levels of cholesterol occur in the bloodstream, excess low-density lipoprotein (LDL, or “bad”) cholesterol seeps into the inner wall of the artery, triggering an inflammatory response. White blood cells are attracted from the bloodstream and smooth muscle cells from the vessel wall migrate and start to form a fibrous cap.

As long as the cap doesn’t rupture, it remains a flow problem: an area of the heart needs more blood than the artery can deliver and chest pain develops, a condition known as stable angina.

With unstable angina, a thin-capped “vulnerable plaque” gets disrupted and the contents of the plaque are exposed to blood. These contents are among the most powerful clot-producing substances known. Many people who have heart attacks do not have thick buildups of plaque caused by high cholesterol but instead have vulnerable plaque that sometimes does not even block the blood flow through the artery.

“Inflammation is key, and cholesterol is part of the trigger,” said Ashley. “The plaque builds up, the fibrous cap ruptures and a clot blocks the artery, causing a heart attack. It’s not so much the size that matters-it’s the stability of the plaque. Often it’s the smaller lesions that open up.”

Reducing Risk
While there is still no way to predict exactly who will have a heart attack, there are still many ways to reduce its risk. Certain factors, like age, gender and genetic makeup, can’t be changed, but most risk factors can be modified for improved cardiovascular health.

Ashley referred to a large-scale, international study that showed that the key factors involved in 90 percent of all heart attacks could be controlled, leading to an 84 percent decrease in cardiovascular risk for study participants. These controllable lifestyle factors include cholesterol, blood pressure, stress, smoking, diet, obesity, alcohol use and exercise.

Ashley also explained the various medications available that work in different ways to reduce heart attack risk. These therapeutics include statins, which lower cholesterol and stabilize the plaques; aspirin or other agents which inhibit the ability of platelet cells to cause clotting; and diuretics, ACE inhibitors and calcium channel blockers, which cause the muscles in the blood vessels to relax and control high blood pressure.

Controllable Factors
As far as diet goes, Ashley said to use common sense and keep everything-including alcohol-in moderation.

“Every day you hear about a different fad diet,” he said. “But a guinea pig has the right idea. Your diet should be low in saturated fat, have lots of whole grains, be high in fiber with lots of fruits and vegetables, and rich in omega-3 fatty acids. Of all the supplements out there, fish oil absolutely does have benefits.”

He also emphasized the importance of reducing stress, and cited a 1998 study that found that heart attack rates in France dropped drastically the day of the World Cup soccer match, illustrating the effect of societal stress on heart health.

As for exercise, Ashley listed more than 25 benefits of a regular regimen, from reduced risk of stroke to increased bone density.

“The heart is a glorious organ- a remarkable muscle that beats more than 3 billion times over a lifetime,” said Ashley. “Overall the message is positive: 90 percent of the risk for heart attack can be explained. I’m a huge fan of lifestyle change, and exercise and diet are clearly part of that.”

At the end of his presentation, Ashley introduced a patient who described his sudden and unexpected heart attack two years ago.

About the Speaker
Euan Ashley, MD, PhD, is an assistant professor of cardiovascular medicine and director of the Stanford Hypertrophic Cardiomyopathy Center, a multidisciplinary program that coordinates care for people with heart muscle disease. He has a particular interest in the care of athletes with cardiovascular disease and works closely with the Stanford Sports Medicine program. He also oversees a research laboratory that is looking at the molecular and genetic causes of heart failure and the fundamental biology of the heart’s signaling pathways. A graduate of the University of Glasgow, Ashley received his DPhil in molecular cardiology from the University of Oxford and his MRCP in medicine from the Royal College of Physicians. He joined the Stanford faculty in 2003.

For More Information:

Request a free information packet on this topic from Stanford Health Library

Ashley’s Research Laboratory
http://medstaging.stanford.edu/ashleylab/

Stanford Human Performance Lab
http://humanperformance.stanford.edu/

Hypertrophic Cardiomyopathy Association
http://www.4hcm.org

American Heart Association
http://www.americanheart.org/presenter.jhtml?identifier=4468

Your Heart on Exercise

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Presented by: Euan Ashley, MD, PhD
Assistant Professor, Cardiovascular Medicine
Stanford University Medical Center
August 14, 2009

Lecture Overview:

  • heartscanHeart rate is controlled by the internal nervous systems:  adrenaline speeds up the heart, while the vagus nerve slows it down
  • Benefits of exercise are numerous, ranging from increased stamina to improved balance and cognition to lowered cholesterol, blood pressure, and risk of heart attack.
  • When exercising, try to keep your heart rate up for at least 30-40 minutes three to five times per week.
  • The differences in an athlete’s heart include slower resting rates, more muscle elasticity, a slightly enlarged chamber, and a slight increase in wall thickness.

The heart, the hardest-working muscle in the body, pumps out about 50 cc of blood at every heartbeat and has the ability to beat more than 3 billion times over a person’s lifetime. It’s the pump that pulses blood throughout the body, delivering oxygen and nutrients to tissue, removing waste, transporting immune-system cells, and regulating temperature.

“Think of the heart as a pump for your fuel supply,” said Euan Ashley, MD, PhD, an assistant professor of cardiovascular medicine and director of Stanford Hospital’s Hypertrophic Cardiomyopathy Center, at a peak Performance Lecture at the 2009 Senior Games. “It is the only organ to be in constant motion and, obviously to me, the most interesting organ in the body!”

A normal heartbeat is initiated by a small pulse of electric current-tiny rhythmic impulses that make the heart muscle contract-produced by cardiac pacemaker cells. Any cell in the heart can take on the pacemaker role, which is one reason the heart can continue to pump when damaged.

Exercise and the Heart
Your heart rate increases even before you actually start to exercise, as eons of evolution prepare your body for the stress and challenge of activity. Your heart responds to two interconnected aspects of the nervous system: The sympathetic system that releases adrenaline, the “fight or flight” hormone that speeds your heart rate and diverts blood from your internal organs, and the parasympathetic system, made up of the vagus nerve, which serves to slow the heart rate down. Withdrawal of the parasympathetic system, which takes care of “rest and digest” functions, is one of the first things to occur before exercise.

To receive the benefits of physical activity, it’s important to check the level at which your heart is working, said Dr. Ashley. For some people, a chest-style heart rate monitor is an excellent way to pace yourself and to acquire the greatest benefit from exercise.

Though many groups suggest you work out your ideal heart rate during exercise by starting with your maximal heart as calculated by 220 minus your age, Dr. Ashley said there is a wide variation in this figure. “Find your own maximal heart rate rather than following an equation,” he suggested. “The idea is to keep your heart rate at 50-60 of the difference between your resting rate and this maximal rate for 45 minutes or more. The more beats per minute, the greater the volume of blood being pumped.”

The Athlete’s Heart
At rest, the heart pumps about 50 ml of blood per stroke; in an untrained athlete, stroke volume can increase to 120 ml with exercise; stroke volume in endurance-trained athletes can reach as much as 200 ml or more. When you run, the heart rate increases. This combination of higher heart rate and higher stroke volume leads to a much greater cardiac output..

“The hallmark of an athlete’s heart is its elasticity. It can increase the volume per beat,” Dr. Ashley said. “It can change volume quite dramatically. It’s the key to performance.”

Dr. Ashley also emphasized the idea that in humans, heart rate is a predictor of longevity. However he mentioned that it is hard to compare species, citing the long-lived whale, whose heart beats about four times a minute, to a shrew, whose heart beats about 1,200 times a minute.

He also referred to the myth that athletes have bigger hearts. An athletes’ heart tends to be about 1 millimeter thicker than average-a very subtle difference. “Heart size does not change that much in an athlete, but extra beats are more common in athletes,” he said.

Benefits of Exercise
Dr. Ashley’s extensive list of the benefits of exercise ranged from cardiovascular improvements to neurological fitness. These include:

  • Increased longevity
  • Reduced risk of heart attack and stroke
  • Improved cholesterol levels
  • Lower blood pressure
  • Less stress
  • Improved mood
  • Better agility and balance
  • Enhanced cognitive function
  • Reduced back pain
  • Endurance
  • Retained bone density
  • Less risk for glaucoma, inflammation, and gallstones
  • Potential anticancer activity for colon, breast, and pancreatic cancers

The only paradox to exercise is a very slight increase in the risk of heart attacks or death from cardiac arrest during exercise. In young athletes, the most common underlying cause is known as hypertrophic cardiomyopathy. This rare genetic disease causes the heart muscle (myocardium) to become abnormally thick, making it harder for the heart to pump blood. Young athletes are now often screened for the disorder. For most people, exercise of moderate intensity for 30 to 40 minutes three or for times a week will provide almost-immediate heart benefits.

“There’s really no downside to exercise,” Dr. Ashley said. “The benefits start to kick in after just 10 minutes.”

About the Speaker
Euan Ashley, MD, PhD, is an assistant professor of cardiovascular medicine and director of the Stanford Hypertrophic Cardiomyopathy Center, a multidisciplinary program that coordinates care for people with heart muscle disease. He is also director of Stanford’s Cardiopulmonary Testing Laboratory. He has a particular interest in the care of athletes with cardiovascular disease and works closely with the Stanford Sports Medicine program. An exercise physiology graduate of the University of Glasgow, Dr. Ashley received his PhD in molecular cardiology from the University of Oxford and his MRCP in medicine from the Royal College of Physicians. He joined Stanford in 2003.

For More Information:

Stanford Health Library can do the searching for you. Send us your medical questions.

Stanford Hypertrophic Cardiomyopathy Center
http://hcm.stanfordhospital.org/

Dr. Ashley’s Research Laboratory
http://ashleylab.stanford.edu/

2009 Summer National Senior Games
http://www.2009seniorgames.org/

Starting an Exercise Program: How Your Doctor Can Help

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Presented by: Paul Wang, MD
Director, Stanford Cardiac Arrhythmia Service

Nawal Atwan, MD
Clinical Instructor, Internal Medicine
Stanford University Medical Center
October 21, 2010

Lecture Overview:

  • Many heart conditions often have no symptoms, so it is important to screen young athletes before they start a sport or activity.
  • Screening should include a health history and a complete physical, which may include an electrocardiogram.
  • People over 40 who have symptoms of chest pain or shortness of breath should have a stress test before starting a new sport.
  • Mix up your routine to include exercises for cardiovascular health, weight training for strengthening muscles, and stretches for flexibility and balance.
  • Start with a plan and steadily increase your goals to measure improvement.

Most people know the many benefits of exercise. Including workouts into your routine has shown to increase longevity, reduce the risk of heart attack and stroke, improve cholesterol levels, lower blood pressure, prevent diabetes, and make you feel better. It helps with weight loss, strengthens bones, and enhances cognitive function-all concerns that affect the quality of life as we age.

Screen for Heart Conditions The only paradox to exercise is a very slight increase in the risk of heart attacks or death from cardiac arrest. Sudden cardiac arrest-when the heart ceases to beat without any warning-is one of the largest heart health problems in the United States. The heart’s electrical system goes awry, making it unable to pump blood to the rest of the body.

The chance of successful resuscitation drops 10 percent every minute, said Paul Wang, MD, director of the Stanford Cardiac Arrhythmia Service and Cardiac Electrophysiology Laboratory, who spoke about cardiovascular evaluation and screening at a presentation sponsored by the Stanford Health Library.

There are more adults with congenital heart defects than ever before, due in large part from improved surgeries. According to the 36th Bethesda Conference, which establishes guidelines for people with cardiac disorders, most congenital heart disease patients have a reduced ability to exercise. Experts are still debating how much exercise is appropriate and whether teens with a heart condition should be allowed to participate in sports.

Many heart conditions often have no symptoms, so it is especially important to screen young athletes before they start to participate in a sport or activity. In athletes younger than age 40, the most common underlying cause of heart problems is known as hypertrophic cardiomyopathy. This rare genetic disease causes the heart muscle (myocardium) to become abnormally thick, making it harder for the heart to pump blood.

The condition tends to manifest in the late teens, and the risk remains an ongoing concern, said Dr. Wang.

“If you’ve had an arrhythmia once, or have a condition that could lead to arrhythmia, the likelihood is higher that you can suffer from cardiac arrest,” he said. “The recommendations are that you should be excluded from most competitive sports.”

There are other conditions that young people should be screened for before taking on a strenuous sport, including anomalous coronary artery, a rare condition that can be detected by an angiogram. These youths should also be restricted in their athletic activities, said Dr. Wang.

In older athletes, the most common cause of problems is coronary artery disease-the buildup of plaque inside the blood vessels. Other conditions of concern include myocarditis, an inflammation of the heart wall, and Marfan syndrome, a disease that weakens the walls of the aorta.

Dr. Wang recommends that all young people see their doctor for a complete physical that includes a health history. An electrocardiogram may be helpful in some cases, but experts are still discussing its benefits. Athletes over 40 who have possible symptoms of heart disease such as chest pain or shortness of breath, and sedentary people with risk factors for heart disease should have a stress test before starting a new regimen. These tests can provide clues to help your physician uncover underlying disease.

“Screening athletes is an important aspect of safety,” he said. “Then follow-up is essential.”

Before You Start to Exercise Nawal Atwan, MD, provided more detail about the benefits of exercise and how to start a healthy regimen. She recommended working out at least 30 minutes five times a week and mixing activities for cardiovascular health, strengthening muscles, and stretching.

She suggested that you start with a plan and steadily increase your goals to measure improvement. Use a pedometer for inspiration, and be realistic about what you can and can’t do. Start with lower goals and then build up the intensity and frequency, she said.

Dr. Atwan suggested a visit to the doctor before starting a new exercise or to assess risk. The physical should assess your blood pressure, heart rate, cholesterol, body mass index (BMI), percentage of body fat, gait, balance, and hand grip. Your doctor may recommend an electrocardiogram or a stress test to measure your heart capacity.

Talk to your physician if you have joint pain or how to prevent developing joint problems. If you have arthritis, you may benefit from a low-impact activity like swimming or water aerobics, which studies have shown can decrease pain, she said. All participants should be sure to stretch as a warm-up and cool-down, holding each position for at least 30 seconds.

“There are lots of excuses to not exercise: no time, no motivation, it’s boring, it hurts. But it’s a matter of getting out there and doing something,” Dr. Atwan said. “Exercise is the cheapest drug around-you can get the same benefits as some medications and without any side effects.”

About the Speakers
Paul Wang, MD, is a professor of medicine (cardiology) and director of the Stanford Cardiac Arrhythmia Service and Cardiac Electrophysiology Laboratory. He received his medical education at the College of Physicians & Surgeons at Columbia University in New York, did his internship at New York Presbyterian Medical Center, and did his fellowship at Brigham and Women’s Hospital at Harvard Medical School.

Nawal Atwan, MD, is a clinical instructor of medicine (internal medicine) who specializes in women’s health, athletic health, and chronic disease management. She received her MD from Harvard Medical School and did her residency at Stanford. She joined Stanford in 2009. She is Board Certified by the American Board of Internal Medicine.

For More Information:

Stanford Health Library can do the searching for you. Send us your medical questions.

About Dr. Wang
http://stanfordhospital.org/profiles/physician/Paul_Wang/

About Dr. Atwan
http://med.stanford.edu/profiles/Nawal_Atwan/

About the Stanford Cardiac Arrhythmia Service
http://stanfordhospital.org/clinicsmedServices/COE/heart/DiseasesConditions/arrhythmia/

American Heart Association
http://www.americanheart.org/presenter.jhtml?identifier=4749

WebMD: Starting an Exercise Program
http://www.webmd.com/fitness-exercise/guide/fitness-beginners-guide

Drug Eluting Stents – Are They Safe?

Posted By SHL Librarian

Presented by: Alan C. Yeung, M.D.
Li Ka Shing Professor of Medicine; Director, Interventional Cardiology; Chief (Clinical), Division of Cardiovascular Medicine
Stanford University Medical Center
September 8, 2007

Lecture Overview:
Recently, stents have garnered considerable attention as questions of safety and efficacy have been discussed among medical experts as well as in the news. The goal of Dr. Yeung’s lecture was to provide information to those who already have a stent or are faced with a decision about getting a stent. This instructive and topical lecture focused on the safety of drug eluting cardiac stents in comparison to stents without drug coating known simply as bare metal stents. The drug eluting stent (DES), and the bare metal stent (BMS) are small metal mesh implants that are inserted into an artery to help keep it open. The coronary artery, only 3mm in diameter, can become clogged with cholesterol, lipids, calcium build-up, clots, and scar tissue. The stent is inserted as part of angioplasty, a procedure used to reestablish blood flow in a clogged artery. A DES is designed to impede the growth of scar tissue, the body’s injury response to the opening the artery. This proliferation of scar tissue, called restenosis, can grow through the stent, causing re-narrowing of the artery and once again interrupting blood flow, and prompting a repeat procedure.

Randomized, double-blinded trials have shown that the DES does a good job of preventing scar tissue formation and contributes to a decrease in repeat procedures, good news indeed since repeat intervention is not without risk. However, with the use of a DES there is a small risk (.2% or 2:1000 per year) of stent thrombosis where clots are formed, sometimes suddenly, a condition not yet completely understood, with the most likely culprit being the delayed healing. The risk of clot formation has to be weighed against the risk of restenosis, and according to Dr. Yeung the evidence is not so alarming to indicate a DES should not be used. However, the ongoing safety of the stent is very much aligned with the continuation of antiplatelet therapy (usually Plavix), particularly during the first year following implantation of a DES. In fact, there is a 29-30% chance of stent thrombosis if antiplatelet medication is stopped prematurely. Dr. Yeung said that compliance with antiplatelet therapy is exceptionally important even if it means delaying elective procedures (orthopedic, dental, etc.) in order to remain on the antiplatelet therapy.

For More Information:

Stanford Health Library can do the searching for you. Send us your medical questions.

Dr. Yeung’s Stanford profile
http://cvmedicine.stanford.edu/faculty/yeung.html

Division of Cardiovascular Medicine
http://cvmedicine.stanford.edu/

Minimally Invasive Cardiac Surgery

Posted By SHL Librarian

Presented by: Michael Fischbein, MD, PhD
Assistant Professor, Cardiothoracic Surgery
Stanford University Medical Center

Lecture Overview:

  • Heart surgery traditionally involves an invasive procedure and the heart is stopped so that surgeons can make the necessary repairs
  • Minimally invasive techniques are being studied to treat a number of heart conditions for certain high-risk patients that previously have been treated only by open heart surgery
  • Smaller incisions mean shorter hospital stays and less recovery time
  • New techniques include replacing heart valves percutaneously and repairing aortic dissections (tears) and aneurysms with endovascular stent grafts

For most patients, heart surgery requires an invasive procedure called a sternotomy (an incision in the chest to access the heart), cardiopulmonary bypass (ability to stop the heart), a hospital stay, and a lengthy recovery period. Both cardiologists and surgeons have developed new, minimally invasive techniques that offer an alternative to certain high-risk patients, particularly older adults who might not recover quickly from major surgery.

Minimally invasive heart surgery is performed through a small incision using specialized surgical instruments. Because the incision is smaller, procedures are less painful and require shorter recovery time. While some of these procedures are still in the testing phase, early results have been extremely promising, said Michael Fischbein, MD, PhD, an assistant professor of cardiothoracic surgery, who described several surgical alternatives at a presentation sponsored by the Stanford Health Library and the San Carlos Public Library.

“There has been incredible progress in technology in the past year or two,” he said.

Coronary Artery Disease
Coronary artery disease is a condition in which plaque builds up inside the coronary arteries, blocking the supply of oxygen-rich blood to the heart muscle, which can lead to angina or heart attacks.

During a coronary artery bypass grafting procedure (CABG), blood flow is rerouted through a new artery or vein grafted past the diseased sections of the coronary arteries. Though a CABG traditionally requires open-chest surgery, it can be done both with and without the use of a heart-lung bypass machine. Certain medical centers are working on performing this operation with robotic assistance without a sternotomy.

Aortic Stenosis
The most common blockage, called aortic stenosis, is the narrowing of the aortic valve, which tends to calcify as we age. When the narrowing becomes significant enough to impede the flow of blood from the left ventricle to the aorta, heart symptoms can develop (chest pain, shortness of breath, or dizziness). Though many elderly Americans show the symptoms of severe aortic stenosis, many are not referred for surgery because of excessive risk factors, age, or comorbidities.

“Once symptoms show up, patients have a 38 percent mortality rate at one year,” said Fischbein. “About half these people are deemed too sick for surgery.”

Stanford is involved in a trial for percutaneous valve replacement that allows surgeons to access the heart by threading a catheter through the femoral artery via the groin, similar to the process used for angioplasty.

“Percutaneous aortic valve replacement is good for high-risk patients who wouldn’t do well on a heart-lung machine,” said Fischbein. “There’s no incision, and no bypass. There’s reduced chance of infection, less procedural pain, shorter recovery period, and hopefully cost effective.”

The technique is being tested in 22 medical centers in the United States, and Stanford is the only test site in Northern California. So far, about 600 people in the U.S. and about 2,000 people in Europe have received a stainless steel stent with a bovine pericardium valve delivered through the femoral artery.
Another option used at Stanford is a mini-sternotomy, which involves a small incision and partial sternotomy. The heart is stopped and an incision made in the aorta to expose the faulty valve. Surgeons can then remove the valve and sew in a new biological or mechanical one.

Thoracic Aortic Surgery
The thoracic aorta can develop abnormal dilations or bulges (aneurysm); the wall may tear, allowing blood to separate the middle and outer layers (dissection); or it may be injured from severe trauma (transection). These conditions can cause the aorta to burst or rupture, causing severe internal bleeding that can rapidly lead to shock or death.

Traditional surgery involves a large incision to repair the abnormal aorta, and procedures often last six hours or more. A minimally invasive technique called endovascular stenting was designed and introduced at Stanford in 1996. The stent graft is placed inside the aorta above and below the aneurysm, allowing the blood to pass through it without pressure on the weak spot caused by the aneurysm or dissection.

A dissection (tear) in the ascending aorta (Stanford Type A) is considered an emergency condition that cannot be treated with minimally invasive methods. A dissection that occurs in the descending aorta (Stanford Type B) is still treated through blood pressure control unless there are complications. If the patient is relatively young or has a connective tissue disease, open surgical repair is performed because the Dacron grafts have exceptional longevity. Endovascular stent grafts may not last as long, which make them more suitable for older patients and as a transition to stabilize a precarious condition.

An aortic transection is caused by a trauma like a car accident—the force can cause a tear in the aorta. Only about 20 percent of the people with this condition even make it to the hospital, said Fischbein, and even then, the mortality rate tends to be high, often because other injuries need to be addressed first. However, using a minimally invasive delivery system allows more rapid response to these patient needs: He described a young man with severe abdominal injuries from a car accident who received a stent graft while in the cath lab, which repaired his aortic injury.

About the Speaker
Michael Fischbein, MD, PhD, is a Stanford assistant professor of cardiothoracic surgery with a special interest in adult thoracic aortic diseases. He has received a number of research and teaching awards, and is a member of several professional medical associations, including the American Heart Association, the International Society of Heart and Lung Transplantation, the Longmire Surgical Society, and the Society of Thoracic Surgeons. He received his MD from Boston University School of Medicine and his PhD in microbiology and immunology from UCLA, where he performed his general surgery training and served as chief resident of the Department of Surgery. He joined Stanford in 2003 for his cardiothoracic surgery residency and joined the faculty in 2006.

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Stanford Heart Center
http://www.stanfordhospital.com/clinicsmedServices/COE/heart/default

Department of Cardiothoracic Surgery
http://ctsurgery.stanford.edu/

American Heart Association
www.americanheart.org/

The Dawn of Personalized Medicine

Posted By SHL Librarian

Presented by: Euan Ashley, MD, PhD
Assistant Professor, Cardiovascular Medicine
Stanford University Medical Center
June 7, 2012

We know that genes play a crucial role in influencing how we look and act, as well as our susceptibility to disease. Now scientists are trying to use that knowledge in exciting new ways, such as preventing and treating health problems based on therapies tailored to an individual’s unique genetic makeup.

But to understand the future of genetically based personalized medicine, it’s important to understand the basics, says Euan Ashley, MD, PhD, an assistant professor of cardiovascular medicine and director of the Stanford Center for Inherited Cardiovascular Disease, who spoke at a presentation sponsored by the Stanford Health Library.

Human DNA is contained within 23 pairs of chromosomes, one half pair from each parent; genes are segments of DNA that determine specific characteristics, such as hair color or height. Some characteristics come from a single gene, while others come from gene combinations. Humans have about 20,000 genes (and so do worms), and the complete instructions they carry are called the human genome.

Genes hold the instructions for making the proteins that manage cell growth and function. When cells duplicate, this genetic information is passed along to the new cells. The genes may mutate over time, causing disease, and such variants can be passed along from parent to offspring. There are more than 3 billion units of information (letters) in the human genome.

Organizing the Information
But the human genome is not quite that straightforward. When mapping the genome, scientists found that blocks of DNA, called haplotype blocks, tend to stay together. By measuring single letter variants called SNPs in each of these blocks, they were able to look across the whole genome at once.

Using a chip to look at the genes or the cell messages that come from the genes was developed at Stanford and now is used as a tool by researchers worldwide. Over the past couple of decades, using such chips, researchers have identified more than 4,000 single genetic variants associated with disease. Most diseases, however, are caused by a multitude of variants acting together.

“Gene chips allowed researchers to look at large populations and associate a genetic variant with a disease,” said Dr. Ashley. “There was a deluge of strong associations within just a few years. Sequencing (spelling out the letters)  the entire genome has come down in price dramatically: 10 years ago a human genome sequence cost about $100 million; today it runs close to $1,000, making the process accessible to most labs and hospitals, and moving toward the day when the genome is used as a routine part of medical practice.

New Clinical Tool
Another enormous step occurred when a Stanford scientist sequenced his entire genome three years ago. He had a family history of severe heart disease that was reviewed by Dr. Ashley—a genetic heart specialist—which made Dr. Ashley the first physician with access to a patient’s complete genome. He put together a team of Stanford scientists to help analyze it.

“Having the patient’s genome available allowed us to look at the possibility of disease, the clinical risk, and what drugs he would or would not respond to,” said Dr. Ashley, referring to pharmacogenetics. “Access to a person’s genome enables us to look at the genetic information in a way that makes sense for clinical medicine. We can look at a patient’s potential response to medication based on their individual genetic makeup.”

Whole-genome sequencing could identify and help prevent heart problems—and other life-threatening diseases—in patients who seem healthy but may be at risk because of an inherited predisposition, he added. Because he could review his patent’s genome, Dr. Ashley was able to make a list of drugs to avoid based on genetic variations associated with reactions with common medicines. His analysis indicated that the patient would respond well to statins.

“Personalized medicine is about individual risk for disease and targeted preventive care,” said Dr. Ashley. “We are only now taking the first steps toward integrating this information into clinical care, and we still have a lot to learn in terms of interpreting the data.”

For now, he adds, clinical applications for an individual’s complete genome have more potential in challenging cases such as rare family syndromes, and studies are underway for genetic response to stent restenosis and drug resistance.

About the Speaker
Euan Ashley, MRCP, DPhil, FACC, FAHA, is an assistant professor of cardiovascular medicine and director of the Center for Inherited Cardiovascular Disease, a multidisciplinary program that coordinates care for adults and children with genetic disorders of the heart and blood vessels. He is a member of the leadership group of the American Heart Association’s Council on Functional Genomics, deputy director of the Stanford Cardiovascular Institute, and a member of the roundtable on genomics of the Institute of Medicine. An exercise physiology graduate of the University of Glasgow, Dr. Ashley received his PhD in molecular cardiology from the University of Oxford and his MRCP in medicine from the Royal College of Physicians. He joined Stanford in 2003.

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About Dr. Ashley

http://stanfordhospital.org/profiles/frdActionServlet?choiceId=printerprofile&fid=7578

Dr. Ashley’s Research Laboratory
http://ashleylab.stanford.edu/

About the Human Genome Project

http://www.ornl.gov/sci/techresources/Human_Genome/project/about.shtml

Heart Disease in South Asians: A Global Epidemic

Posted By SHL Librarian

Presented by:  Rajesh Dash, MD, PhD
Assistant Professor, Cardiovascular Medicine
Stanford University Medical Center
September 25, 2014

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A healthy 44-year-old Indian man who exercises regularly, has normal cholesterol and blood pressure, and who smokes and drinks only occasionally should not have to worry about a heart attack. On paper, everything looked fine. His doctor found no cause for putting him on statins to lower his cholesterol.

However a family history found that his brother already had a heart attack, his mother had three stents implanted to open her vessels, and three uncles had died from a heart attack before age 60. When the patient agreed to have a coronary CT scan, the results showed that one of the vessels near his heart was almost completely blocked. He received a stent and was put on an aggressive medical regimen.

The question remains: Why him?

The fact is, people from South Asia—India, Pakistan, Bangladesh, Nepal, and Sri Lanka—have a four times greater risk of heart disease than the general population and have a much greater chance of having a heart attack before age 50. Heart attacks strike South Asian men and women at younger ages and are more deadly compared to any other ethnic group: Almost a third dies from heart disease before age 65. In India cardiovascular disease remains the No. 1 cause of death. One study found that South Asians developed heart disease 10 years earlier than other groups,

“South Asian men and women age 20 to 55 are at high risk, show higher mortality rates, and symptoms and risk factors appear to begin earlier,” said Rajesh Dash, MD, PhD, an assistant professor of cardiovascular medicine, who spoke at a presentation sponsored by Stanford Hospital Health Library. “They’re younger, sicker (at first presentation), and dying earlier.”

High Risk Factors
Traditional risk factors like diet and lifestyle are a big part of the problem, he said. South Asians tend to be smokers, and the traditional South Asian diet tends to be high in sugar, refined grains, and fatty foods. Many South Asians appear to be insulin resistant, a pre-diabetic condition in which the body does not process insulin efficiently.

“Insulin-resistant patients have similar rates of cardiovascular events as those with full-blown diabetes,” Dr. Dash said. “Most people are not normally tested for the condition, but it is especially important for South Asians to be tested. If diagnosed, the condition often can be controlled with diet and lifestyle changes.”

Other traditional risk assessments, like body mass index (BMI), appear to be poor predictors for South Asians, who often show a “thin-fat” syndrome where they fall within BMI standards but have more visceral fat—abdominal fat that is more likely to lead to a cardiovascular event. Waist circumference or waist-to-hip ratio may be more predictive measurements for this group, who also should aim for a lower overall BMI.

More than one third of South Asian men and 17 percent of South Asian women have metabolic syndrome, a cluster of conditions such as high blood pressure, high blood sugar levels, excess body fat around the waist, and abnormal cholesterol levels that increase the risk of heart disease, stroke, and diabetes. If more than one of these conditions occur in combination, the risk is even greater. This syndrome is not normally checked during an annual physical exam. South Asians are more likely to have high triglycerides and low HDL (the “good” cholesterol). A variant of HDL known as HDL2b is low in as much as 93 percent of South Asian men and 63 percent of women.

“Despite having a low BMI and low cholesterol, the composition of the cholesterol is abnormal,” said Dr. Dash. “A nontraditional assessment is called for.”

Focused Attention
Dr. Dash is the medical and scientific director for the Stanford South Asian Translational Heart Initiative (SSATHI), a new program designed to address the unique concerns of the South Asian population. It combines researchers who are looking at genetic and metabolic factors with clinicians who are treating patients and refining screenings for risk.

“Our target is younger people so that we have the opportunity to address and treat symptoms and risks before they develop into cardiovascular disease,” he said. “Our mission is to reduce the incidence of cardiovascular disease through aggressive screening, aggressive treatment, expedited appointments, and long-term follow-up in management and risk reduction. The disease is more aggressive, so we have to treat it that way.”

The research team is made up of experts in genetics, imaging, bioinformatics, cardiovascular medicine, heart surgery, and stem cell therapy. They are looking at biomarkers for genetic risk, cardiac fibrosis, drug sensitivity, insulin resistance, and vascular reactivity. In particular, program physicians are looking at nontraditional risk factors like elevated lipoprotein levels, insulin resistance, low HDL2b, and relevant genetic mutations.

The clinical team is focused on risk reduction, prevention, and treatment. Patients first provide a family history and undergo a detailed laboratory evaluation. They are stratified for risk and short-term goals are set. A second visit about two months later includes diet consultation with a South Asian cuisine-trained dietitian, cardiovascular risk scoring, a review of lab test results, and a request to enroll in the program’s research trials. A third visit after six months summarizes the research results, tracks compliance, repeats the biomarker screening, and develops a long-term plan. Some patients may continue receiving care through SSATHI, while others may find their risk is sufficiently reduced to continue their care elsewhere.

In time, Dr. Dash hopes to develop partnerships to address the issue at a global scale and expand the program’s studies beyond the South Asian population.

“We want to teach people how to protect themselves from cardiovascular disease,” Dr. Dash said. “The problem is very real and accelerating. It’s a troubling trend that has not been addressed sufficiently and one that needs to be addressed earlier.”

About the Speaker
Rajesh Dash, MD, PhD, is an assistant professor of medicine (cardiovascular medicine) and the medical and scientific director of the Stanford South Asian Translational Heart Initiative (SSATHI). He received an MD and a PhD in pharmacology and cell biophysics from the University of Cincinnati. He did his residency at the University of Washington School of Medicine and completed his fellowship at UCSF Medical Center. He is board certified in echocardiography by the National Board of Echocardiography and in cardiovascular disease and internal medicine by the American Board of Internal Medicine.

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About Dr. Dash

Stanford South Asian Translational Heart Initiative (SSATHI)

Cardiovascular Health Care

Stanford Cardiovascular Institute