Saturday, December 25, 2010
Saturday, December 18, 2010
Activity
Since I have been less than effusive in my posting I will add twitter, fb posts here as well.....
Experts warn of epidemic of "worn out" heart valves. http://bbc.in/gL9qgu
Experts warn of epidemic of "worn out" heart valves. http://bbc.in/gL9qgu
Thursday, July 15, 2010
Vice President Cheney, Heart Failure and Heart Pumps
The news is awash with reports that former Vice President Dick Cheney had a "heart pump" implanted last week as treatment for his congestive heart failure. Although the details are not available, multiple reports consistently state that he has had heart problems through out most of his adult life, sustaining his first heart attack at age 37. He is quoted in the recent release as stating the he was "entering a new phase of the disease when I began to experience increasing congestive heart failure" and it is further stated that he had a 'heart pump' implanted.
Congestive heart failure is a condition in which the heart muscle is severely weakened reducing its ability to adequately pump blood. It is a very common condition and affects almost 5 million people in the U.S. Heart failure is the single most common reason people are admitted to the hospital. Some heart failure statistics:
-4,8000,000 people with heart failure in US, 2% of population in their 50's, 5% in their 60's, and 10% of population over 70
-875,000 hospital admissions every year in US for heart failure (2400/day). Number one admitting diagnosis
-400,000 newly diagnosed cases of heart failure annually in US (1100/day)
-55,000 people in US die every year due to heart failure (139/day)
-66% of heart failure patients die within 5 years of their diagnosis (worse then most cancers)
-2 people died of heart failure while you were reading this blog post.
Obviously there is considerable room for improvements in the treatment of this condition. Common symptoms of heart failure are shortness of breath, initially with significant exertion, but as it progresses this occurs with less activity. In it's more severe extent, New York Heart Association classification 3B or 4, these patients cannot walk undertake normal activities of daily living without having to stop due to shortness of breath. Other symptoms include swelling of the legs, waking up at night short of breath, having to sleep with the head elevated to facilitate breathing, having to urinate multiple times at night, palpitations and generalized fatigue.
The most common causes of heart failure include coronary artery disease, heart valve problems, and viral cardiomyopathy. Treatment includes dealing with the underlying etiology, which may totally alleviate the heart failure, and/or medicines. As heart failure progresses, in situations where the underlying cause was not reversible, it becomes harder to treat and the symptoms interfere with normal daily activities.
Heart Pumps
In severe cases of heart failure, when medications are no longer effective, and a patients symptoms progress to the point of interfering with normal activities of daily living, a heart pump or left ventricular assist device may be recommended. These bits of ingenious technology have progressed significantly in recent years. The HeartMate II system is the most advanced system currently approved by the FDA. Although not confirmed, this is the device VP Cheney has been purported to have received.
The HeartMate II is a continuous flow device, with a single moving part, a propeller, of sorts, that spins at around 10,000 rpms to aid in the emptying of the heart and restoring normal circulation. Since this device moves the blood at a constant, consistent rate, rather then the rhythmic squeezing type of pumping, these patients usually do not have a palpable pulse.
The indications for implantation of a left ventricular assist device, or LVAD, are for bridging to transplantation, or destination therapy. Bridge to transplant is just what it sounds like, maintaining adequate circulation and restoring the ability to resume full activities while awaiting availability of an appropriate donor organ. Destination therapy is for patients who are not candidates for transplantation and the LVAD serves as the permanent treatment for heart failure in these patients.
In recent studies, the HeartMate II has proven to be very reliable, with 2 year patient survival at about 90% and overall complication rates significantly lower than previous generation devices. Additionally most patient are able to resume full activities. A number of the early recipients of this device are now over 5 years out from their initial implant.
Considering almost 5 million heart failure patients and only 2500 LVAD implants in the US, there is room for much improvement in the lives of many people with this remarkable new technology. I wish Mr. Cheney, and all patients in similar circumstances, a speedy recovery and best wishes for a bright and fulfilling future.
See http://www.youtube.com/watch?v=2auyZ54x2uA for an interview with a recent HeartMate II recipient.
Congestive heart failure is a condition in which the heart muscle is severely weakened reducing its ability to adequately pump blood. It is a very common condition and affects almost 5 million people in the U.S. Heart failure is the single most common reason people are admitted to the hospital. Some heart failure statistics:
-4,8000,000 people with heart failure in US, 2% of population in their 50's, 5% in their 60's, and 10% of population over 70
-875,000 hospital admissions every year in US for heart failure (2400/day). Number one admitting diagnosis
-400,000 newly diagnosed cases of heart failure annually in US (1100/day)
-55,000 people in US die every year due to heart failure (139/day)
-66% of heart failure patients die within 5 years of their diagnosis (worse then most cancers)
-2 people died of heart failure while you were reading this blog post.
Obviously there is considerable room for improvements in the treatment of this condition. Common symptoms of heart failure are shortness of breath, initially with significant exertion, but as it progresses this occurs with less activity. In it's more severe extent, New York Heart Association classification 3B or 4, these patients cannot walk undertake normal activities of daily living without having to stop due to shortness of breath. Other symptoms include swelling of the legs, waking up at night short of breath, having to sleep with the head elevated to facilitate breathing, having to urinate multiple times at night, palpitations and generalized fatigue.
The most common causes of heart failure include coronary artery disease, heart valve problems, and viral cardiomyopathy. Treatment includes dealing with the underlying etiology, which may totally alleviate the heart failure, and/or medicines. As heart failure progresses, in situations where the underlying cause was not reversible, it becomes harder to treat and the symptoms interfere with normal daily activities.
Heart Pumps
In severe cases of heart failure, when medications are no longer effective, and a patients symptoms progress to the point of interfering with normal activities of daily living, a heart pump or left ventricular assist device may be recommended. These bits of ingenious technology have progressed significantly in recent years. The HeartMate II system is the most advanced system currently approved by the FDA. Although not confirmed, this is the device VP Cheney has been purported to have received.
The HeartMate II is a continuous flow device, with a single moving part, a propeller, of sorts, that spins at around 10,000 rpms to aid in the emptying of the heart and restoring normal circulation. Since this device moves the blood at a constant, consistent rate, rather then the rhythmic squeezing type of pumping, these patients usually do not have a palpable pulse.
The indications for implantation of a left ventricular assist device, or LVAD, are for bridging to transplantation, or destination therapy. Bridge to transplant is just what it sounds like, maintaining adequate circulation and restoring the ability to resume full activities while awaiting availability of an appropriate donor organ. Destination therapy is for patients who are not candidates for transplantation and the LVAD serves as the permanent treatment for heart failure in these patients.
In recent studies, the HeartMate II has proven to be very reliable, with 2 year patient survival at about 90% and overall complication rates significantly lower than previous generation devices. Additionally most patient are able to resume full activities. A number of the early recipients of this device are now over 5 years out from their initial implant.
Considering almost 5 million heart failure patients and only 2500 LVAD implants in the US, there is room for much improvement in the lives of many people with this remarkable new technology. I wish Mr. Cheney, and all patients in similar circumstances, a speedy recovery and best wishes for a bright and fulfilling future.
See http://www.youtube.com/watch?v=2auyZ54x2uA for an interview with a recent HeartMate II recipient.
Saturday, May 15, 2010
Barbara Walters and Aortic Stenosis
Celebrities deserve the same rights to privacy, with respect to their medical conditions, as everyone else. However, when they chose to go public with details about their health, it can raise the public awareness of medical conditions and aid in education. Such was the case this week with Barbara Walters revelation that she has aortic stenosis and was scheduled to undergo valve replacement surgery.
Aortic stenosis affects approximately 6% of the US population or about 3.5 million people. The incidence increases with age. About 2% of 60 year olds, 3% of 70's and 4% of 80 year olds are affected.
The aortic valve is between the left ventricle (main pumping chamber of the heart) and the aorta (the main artery leaving the heart to the rest of the body). Normally it is comprised of 3 very thin leaflets. When the ventricle squeezes, the force of the blood ejecting opens the valve completely allowing the blood to pass into the aorta. The valve then closes so the blood does not leak back into the heart but continues its forward movement. The gradient, or pressure difference across the valve is normally essentially zero.
Aortic stenosis is a condition in which the leaflets of the valve thicken and stiffen. This then reduces their mobility and the heart is now pumping against a partially closed door. As this process continues the stiffness of the valve progresses and the opening shrinks leading to a significant gradient across the valve. About 15% of the population is born with an aortic valve that has 2 leaflets instead of 3. These valves are more prone to developing aortic stenosis, though usually not until later in life. Some however are tight from birth and require surgery in childhood.
A mean gradient of 40 mm of mercury is generally considered significant. With a gradient of 40 across the valve if the blood pressure measured in your arm is 120/ the pressure within the ventricle would then be 160/. If the gradient was 80 a BP of 120/ would mean the intra-cardiac pressure is 200, and so on. This is not a good situation for the heart.
Another measurement of the valve involves estimating the cross sectional area of the opening. Echocardiography is a good way to view this and an area of less than one centimeter is considered severe aortic stenosis.
As you would expect, the heart has to pump harder to push the blood thru this smaller opening. It causes the muscle to strain and thicken. The jet going thru the narrow opening is like putting your finger over the end of an open water hose. The resulting increased blood velocity can cause the aorta to enlarge. Also the straining of the heart to pump against this resistance can lead to chest pain, rhythm problems, fainting spells and heart failure. When fainting spells or heart failure develop from aortic stenosis there is a 50% risk of dying within 3 years.
For patients with symptomatic or severe aortic stenosis surgery to replace the valve is recommended. This is a mechanical problem and there are no medications to reverse it. There is also no good evidence that diet is implicated in its development or treatment.
Surgery to replace the aortic valve is typically performed thru a sternotomy (splitting the breastbone), however in many cases minimally invasive options are available (see previous post). A procedure to implant aortic valves via a needle stick in the groin is currently under investigation in the US.
There are a number of choices of valve type for replacing the aortic valve. Bioprosthetic or tissue valves are the most common choice in the US. These valves are either the aortic valves from pig hearts or are constructed from the pericardium (sac the heart lives in) of cows or horses. These are mounted on a covered stent and are available in a range of sizes. The advantage of tissue valves is that no medication is required following their implantation. The disadvantage is that they wear out. Current generations of valves have improved durability and their longevity is said to be over 90% at 12 years following implant.
The second most common type of valve is a mechanical valve. These are manufactured from pyrolytic carbon and have a bi-leaflet design. They look like a disc split in half that pivots open and closed with the blood flow. The advantage of this type of valve is that it can last virtually indefinitely. The disadvantage is that a blood thinner (warfarin or Coumadin) is required indefinitely.
These two valve types account for the vast majority of valve replacements.
Other options include homograft (cadaver human) valves and autografts. Autografts involve a procedure known as the Ross procedure in which a patients own pulmonary valve is removed and placed in the aortic position, then a homograft in used to replace the pulmonary valve.
How is a decision made as to which type of valve to implant? In the absence of any mitigating factors, age is a reasonable guideline for deciding. It is generally recommended that individuals less than 65 receive mechanical valves and over 65 lean toward tissue valves. This is NOT a hard and fast rule but a guide, and either valve type can be reasonably placed in either population. Obviously if a patient is unwilling or unable to take a blood thinner and have his blood routinely checked, then a mechanical valve is not for him.
Bottom line is that there are many good options. A thorough discussion of options, pros and cons with your surgeon is imperative prior to proceeding with your surgery
Aortic stenosis affects approximately 6% of the US population or about 3.5 million people. The incidence increases with age. About 2% of 60 year olds, 3% of 70's and 4% of 80 year olds are affected.
The aortic valve is between the left ventricle (main pumping chamber of the heart) and the aorta (the main artery leaving the heart to the rest of the body). Normally it is comprised of 3 very thin leaflets. When the ventricle squeezes, the force of the blood ejecting opens the valve completely allowing the blood to pass into the aorta. The valve then closes so the blood does not leak back into the heart but continues its forward movement. The gradient, or pressure difference across the valve is normally essentially zero.
Aortic stenosis is a condition in which the leaflets of the valve thicken and stiffen. This then reduces their mobility and the heart is now pumping against a partially closed door. As this process continues the stiffness of the valve progresses and the opening shrinks leading to a significant gradient across the valve. About 15% of the population is born with an aortic valve that has 2 leaflets instead of 3. These valves are more prone to developing aortic stenosis, though usually not until later in life. Some however are tight from birth and require surgery in childhood.
A mean gradient of 40 mm of mercury is generally considered significant. With a gradient of 40 across the valve if the blood pressure measured in your arm is 120/ the pressure within the ventricle would then be 160/. If the gradient was 80 a BP of 120/ would mean the intra-cardiac pressure is 200, and so on. This is not a good situation for the heart.
Another measurement of the valve involves estimating the cross sectional area of the opening. Echocardiography is a good way to view this and an area of less than one centimeter is considered severe aortic stenosis.
As you would expect, the heart has to pump harder to push the blood thru this smaller opening. It causes the muscle to strain and thicken. The jet going thru the narrow opening is like putting your finger over the end of an open water hose. The resulting increased blood velocity can cause the aorta to enlarge. Also the straining of the heart to pump against this resistance can lead to chest pain, rhythm problems, fainting spells and heart failure. When fainting spells or heart failure develop from aortic stenosis there is a 50% risk of dying within 3 years.
For patients with symptomatic or severe aortic stenosis surgery to replace the valve is recommended. This is a mechanical problem and there are no medications to reverse it. There is also no good evidence that diet is implicated in its development or treatment.
Surgery to replace the aortic valve is typically performed thru a sternotomy (splitting the breastbone), however in many cases minimally invasive options are available (see previous post). A procedure to implant aortic valves via a needle stick in the groin is currently under investigation in the US.
There are a number of choices of valve type for replacing the aortic valve. Bioprosthetic or tissue valves are the most common choice in the US. These valves are either the aortic valves from pig hearts or are constructed from the pericardium (sac the heart lives in) of cows or horses. These are mounted on a covered stent and are available in a range of sizes. The advantage of tissue valves is that no medication is required following their implantation. The disadvantage is that they wear out. Current generations of valves have improved durability and their longevity is said to be over 90% at 12 years following implant.
The second most common type of valve is a mechanical valve. These are manufactured from pyrolytic carbon and have a bi-leaflet design. They look like a disc split in half that pivots open and closed with the blood flow. The advantage of this type of valve is that it can last virtually indefinitely. The disadvantage is that a blood thinner (warfarin or Coumadin) is required indefinitely.
These two valve types account for the vast majority of valve replacements.
Other options include homograft (cadaver human) valves and autografts. Autografts involve a procedure known as the Ross procedure in which a patients own pulmonary valve is removed and placed in the aortic position, then a homograft in used to replace the pulmonary valve.
How is a decision made as to which type of valve to implant? In the absence of any mitigating factors, age is a reasonable guideline for deciding. It is generally recommended that individuals less than 65 receive mechanical valves and over 65 lean toward tissue valves. This is NOT a hard and fast rule but a guide, and either valve type can be reasonably placed in either population. Obviously if a patient is unwilling or unable to take a blood thinner and have his blood routinely checked, then a mechanical valve is not for him.
Bottom line is that there are many good options. A thorough discussion of options, pros and cons with your surgeon is imperative prior to proceeding with your surgery
Saturday, February 27, 2010
Dietary/Nutritional education
Jamie Oliver gets it. Juvenile obesity and diabetes are on the rise. Most of the "diseases of affluence" start during youth. To make a real lifelong impact, nutritional education must start in school or before. Check out his talk at TED http://www.ted.com/talks/jamie_oliver.html
Monday, February 22, 2010
Forks over Knives
New film being made about Drs. Campbell and Esselstyn and their research. Trailer looks great, check out the website and view the trailer: http://forksoverknives.com/
Wednesday, February 10, 2010
Richmond Times Dispatch
Amazed at number of positive responses to newspaper article today. http://bit.ly/913XmP
Working on setting up seminars, support groups. Many have questions about the study, we have a grant proposal pending on; it will be for those with documented coronary artery disease to measure the impact of diet on the disease. For others, stay tuned working on more options.
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