Heart problems

Coach John Fox and Aortic Valve Replacement

November 3, 2013 By Larry Creswell, MD 5 Comments

NFL Broncos head coach, John Fox, will reportedly undergo aortic valve replacement (AVR) this week. I’ve gotten some inquiries over the weekend about his situation and I thought I’d take a few minutes to write about aortic valve problems and aortic valve replacement.

This story is reminiscent of Atlanta Falcons coach, Dan Reeves, who had urgent coronary artery bypass surgery in 1998, late in his team’s 14-2 season. For reference, Reeves made an excellent recovery, rejoined the team just 3 weeks after surgery, and went on to coach for another 5 seasons.

Aortic Valve Disease

The aortic valve is the valve that lets blood out of the heart. The left ventricle of the heart pumps blood out through this valve into the aorta with each heart beat. At rest, this might amount to about 5 liters per minute. The valve ordinarily has 3 tissue thin leaflets, but some individuals are born with just 2, a condition known as bicuspid aortic valve (BAV).

There are 2 different problems with the aortic valve. The valve can become narrowed or it can leak. Either situation produces trouble for the heart, which then must do extra work. When the valve is narrowed, we call the condition aortic stenosis. When the valve leaks, we call the condition aortic regurgitation. When there is severe aortic stenosis or regurgitation, aortic valve replacement is often the only available curative treatment.

In this country the most common cause of aortic stenosis in adult patients, by far, is build-up of calcium in the valve leaflets over many years’ time. This progressive calcification causes the valve leaflets to become thickened. As a result, they don’t open or close easily and eventually they become immobile. Severe aortic stenosis most often manifests in patients 60+ years old. In individuals with BAV, this process occurs much earlier in life, and the condition often manifests in patients in their 40’s and 50’s. Rheumatic fever is probably the next most common cause. The normal aortic valve opening is about the size of a half dollar. But with severe aortic stenosis, the opening can be reduced to the size of a drinking straw.

Aortic regurgitation may occur for a variety of reasons such as: infection (that we call endocarditis) that destroys the valve leaflets; enlargement of the aorta that stretches the leaflets apart; rheumatic fever; or trauma.

Patients with severe aortic stenosis have symptoms of shortness of breath with exertion, chest pain/discomfort, or light-headedness or blacking out (that we call syncope). Patients with aortic regurgitation most often have symptoms of shortness of breath with exertion. Either condition can be revealed by listening to the heart with a stethoscope because either condition produces turbulent blood flow that can be heard as a heart murmur. The diagnosis is confirmed using ultrasound, in a test known as an echocardiogram.

Once there are symptoms, patients with severe aortic stenosis need operation. Once the heart function suffers because of aortic regurgitation, operation is needed. In either case, we usually plan for operation at the earliest, convenient opportunity. Emergency operations for aortic valve problems are unusual.

In John Fox’s case, we know from reporting that he was in Charlotte, North Carolina to visit his doctor(s) about a known aortic valve problem–one that was being monitored and for which aortic valve replacement was being planned once this year’s football season was complete. The initial news reports spoke about the possibility of a heart attack, but he apparently became light-headed while playing golf. It’s not clear if he passed out completely. He was taken to the hospital where additional testing was completed. The Broncos then made the announcement that Fox would undergo surgery this coming week.

Aortic Valve Surgery

Aortic valve replacement is a very common heart operation today. And while there are new technologies that allow for valve replacement in high-risk patients without conventional operation, the vast majority of patients undergo typical open heart surgery to replace the valve.

The patient has general anesthesia with use of a breathing tube to provide ventilation while asleep. Access to the heart is gained by dividing all or part of the sternum and using a retractor to spread the rib cage open. The first main part of the operation involves connecting the patient to a heart-lung bypass machine that sits at the side of the operating table and takes over the job of the patient’s own heart and lungs for a period of time. This allows the patient’s heart to be still and empty of blood.

The next main part involves replacing the valve. An opening is made in the aorta, the large blood vessel that carries blood away from the heart. This allows the surgeon to look in and see the diseased valve. In the most straightforward operation, the patient’s aortic valve is removed using scissors and any calcium-related debris is also removed. A measuring tool is used to determine the correct size for a substitute valve which is then taken from the shelf. Sutures are used to sew the substitute valve into the opening left behind where the patient’s valve was removed. The opening in the aorta is then closed with sutures.

The last major part of the operation involves letting the patient’s own heart and lungs take back over again, and gradually reducing the amount of help that the heart-lung machine provides. Once the patient’s heart is beating again, the sternum is re-approximated with wires and the overlying tissues and skin are re-approximated using sutures. The entire operation usually takes about 3 hours.

There are several options for substitute valves. Mechanical valves are made out of space-age materials and are designed to last forever, but patients must take blood thinning medications to prevent blood clots from forming on the prosthetic valve. Tissue valves (eg, aortic valve “borrowed” from a pig) don’t require anticoagulants, but the valves don’t last forever. The modern tissue valves can be expected to last 10-15 years in adult patients and then some will deteriorate; re-replacement of the valve may sometimes be needed. In special circumstances, other more exotic options may be appropriate, but we won’t consider those options today.

Recovery from Operation

The typical patient wakes up soon after the operation. The breathing tube and ventilator are withdrawn once the patient is wide awake and breathing on his/her own. Most patients will spend a night in the intensive care unit and then several more days recovering in a regular hospital room. A typical stay would be about 5-7 days. We work hard to have patients up and walking on the first day after operation and most are walking laps around our hospital ward by the time they go home.

Many patients with AVR notice even in just the first couple days after operation that they no longer have the symptoms that led to discovery of their problem. Particularly for aortic stenosis, the calcification of the valve happens so gradually that patient’s aren’t always aware of how much of a decrement there’s been in their exercise tolerance.

As the sternum heals, we ask that patients avoid physical activities that place stress on the sternum and shoulders (eg, pushing, pulling, reaching, etc.) for 1 month after the operation. The sternum regains about 75% of its strength in about 1 month. In my practice we also restrict driving for that same month. Most any other activity is allowed and we encourage lots of walking as the preferred type of exercise.

Each patient’s situation with return-to-work is different, not only because each patient’s recovery is different but also because each patient’s job situation is different. In Fox’s case, if all goes well, I wouldn’t be surprised to see him back at work, at least in some capacity, very quickly.

Best wishes to John Fox!

More on Athletes and Bicuspid Aortic Valve (BAV)

September 26, 2013 By Larry Creswell, MD 145 Comments

I probably get more inquiries from athletes with bicuspid aortic valve (BAV) than any other single heart problem. Maybe that’s not surprising, given that I’m a heart surgeon and that many individuals with BAV need operation at some point. Nonetheless, I think there’s considerable confusion about this condition, in terms of diagnosis, implications for the athlete, and its treatment.

I first wrote about BAV in a short post here at the blog back in 2009. That post is a starting point for today’s discussion.

To quickly review, individuals with BAV have an aortic valve with 2 unequal–instead of the usual 3 equal sized–leaflets. As a consequence, these individuals develop earlier calcification of the valve leaflets, leading to narrowing, or stenosis. They are also predisposed to enlargement of the ascending aorta, the large blood vessel that carries blood flow away from the heart. This can lead to stretching apart of the valve leaflets and leakage at the valve, known as regurgitation.

Looking through the reader comments here at the blog and reflecting on the athlete inquiries I’ve received, I thought I’d cover some of the major issues.

First, you’re not alone!

BAV is one of the most common congenital heart conditions, occurring in about 2% of individuals. In large-scale pre-participation cardiac screening programs for young, competitive athletes, BAV is one of the most commonly identified abnormalities.

Historically, a heart murmur was the most common reason affected individuals were identified. Today, echocardiography (ultrasound) for screening or diagnostic purposes for some other heart problem is the most common way that BAV is detected.

Finally, athletes are not spared. Several contemporary elite triathletes have BAV and I’ve written about their stories in:

Examples from other sports would include Arnold Schwarzenegger, among others.

And of course the problem occurs in everyday, recreational athletes, too. Check out Anthony DiLemme’s blog, Anthony’s Heart Valve Replacement Saga. He’s a 30-year-old 8th grade science teacher, a cyclist and outdoorsman, who is chronicling his story with BAV–from diagnosis, to evaluation, to preparations for upcoming valve replacement surgery. His story is typical.

On the bright side, there is ample evidence that, in the modern era, life-expectancy is not shortened for individuals with BAV compared to the general population. That’s important to keep in mind.

Before operation is needed

It’s worth knowing if you have BAV.

Aside from the problems with aortic valve stenosis or regurgitation or with enlargement of the aorta, individuals with BAV can also suddenly develop the problem of aortic dissection. With aortic dissection, the aorta can develop a tear on its inside wall, leading to unraveling of its layers, and even rupture. This is thought to occur at a rate of about 0.1% per year in adults. This can be a life-threatening problem and is more apt to occur with progressive enlargement of the aorta and with uncontrolled high blood pressure.

The American College of Cardiology (ACC) in conjunction with the American Heart Association (AHA) has issued guidelines for the evaluation, monitoring, and treatment of individuals with BAV:

Patients with known BAV should undergo:
- An echocardiogram to evaluate the aortic valve for stenosis or regurgitation and to assess for any other structural heart problems
- A chest CT scan to make measurements of the diameter of the aorta at various points along its length.
Cardiac CT scan or magnetic resonance imaging (MRI) are alternatives if echocardiography is not available or possible for some reason
If there is enlargement of the beginning portion of the aorta to greater than 4.0 cm, the individual should have a yearly assessment of the diameter of the aorta
Medical therapy may be useful to slow or halt the progression of aortic valve disease and aortic enlargement by reducing the blood pressure and the blood pressure across the aortic valve. Beta-blockers (eg, metoprolol) are recommended for this purpose.
Because BAV may be an inherited condition, first-degree relatives of individuals with BAV should undergo evaluation.

In my opinion, these are useful guidelines for athletes and non-athletes, alike. The guidelines do not address the frequency of surveillance for individuals with BAV and no enlargement of the aorta. For these individuals, provided there is no other relevant heart disease, it may be appropriate to have follow-up echocardiogram and/or CT scanning every 2 years.

The data regarding the progression of disease in athlete patients with BAV are limited. Guidelines specifically for athletes come from the Proceedings of the 36th Bethesda Conference in 2005. Parenthetically, it may be time for an update. The guidelines were developed by an expert panel based on the scientific information available at that time:

Athletes with BAV, no significant valve stenosis or regurgitation, and an aortic diameter less than 4.0 cm can participate fully in their sport(s)
Athletes with BAV and enlargement of the aorta to between 4.0 and 4.5 cm can participate safely in only low and moderate intensity sports (this would exclude the typical endurance sports of swimming, cycling, running, triathlon, etc.)
Athletes with BAV and enlargement of the aorta to greater than 4.5 cm can participate safely only in low intensity sports (eg, golf, bowling, billiards).

The issue has not been studied very well, but one recent study suggests that continued participation in sports for periods of up to 5 years does not change the natural history and progression of BAV. Instead, even with continued sports participation, the progression of both valvular and aortic disease is no different from that in the general population.

Who needs operation?

Operation is needed if there is severe aortic valve stenosis, severe valve regurgitation, or significant enlargement of the aorta. Again, there are ACC/AHA guidelines for when operation is needed:

Aortic valve replacement is recommended for nearly all patients with severe valve stenosis (valve opening less than 1.0 cm2)
Aortic valve replacement is recommended for patients with severe valve regurgitation if there are symptoms due to the regurgitation (eg, shortness of breath with exertion) or evidence that the heart is suffering because of the regurgitation (enlargement of the left ventricle)
Repair or replacement of the beginning portion of the aorta is recommended if there is enlargement of the aorta to greater than 5.0 cm or if the rate of increase in the aortic diameter exceeds 0.5 cm per year

Sometimes more than one indication for operation may be present, so there is the additional guideline for patients who need operation for aortic stenosis or regurgitation:

In patients needing valve replacement because of stenosis or regurgitation, the aorta should be repaired or replaced if the aortic diameter exceeds 4.5 cm.

I know from discussion with athletes over the past few years that there are differences of opinion among cardiologists and heart surgeons about these guidelines. These differences of opinion may be legitimate. Consensus guidelines are developed to be broadly applicable, but the guidelines may not be applicable in a given athlete patient’s circumstance. There are a multitude of patient-specific circumstances that must be considered when deciding if and when operation is needed. Only your cardiologist and heart surgeon will be in a position to make those considerations.

In practice, the indications for aortic valve replacement for severe aortic stenosis or severe aortic regurgitation are straightforward and uncontroversial. It’s also clear-cut that patients with significant enlargement of the aorta to greater than 5.0 cm need operation for replacement of the aorta.

One situation that seems particularly ripe for differences of opinion is that of the athlete with BAV, no significant stenosis or regurgitation, but with an aortic diameter of 4.5 to 5.0 cm. This is an unfortunate situation for the athlete patient because the consensus guidelines do not yet recommend operation, yet advise against strenuous sports activities. My personal approach to endurance athletes in this situation would be to offer operation if the patient wanted to continue to participate in endurance sports (after operation) and was willing to assume the risks of operation. But I recognize that not all cardiologists or heart surgeons would agree.

Options for operation

Substitute valves. There are 2 broad categories of heart valve substitutes that can be used to replace the human aortic valve: mechanical valves or bioprosthetic (“tissue”) valves.

Mechanical valve. These valves are constructed from high-tech materials that are designed to last essentially forever. Unfortunately, these materials may cause tiny blood clots to form on their surface and, for that reason, patients must take blood-thinning medications (eg, warfarin) forever to prevent this complication. The major brands include St. Jude Medical, Medtronic, Sorin-Carbomedics, and On-X.
Bioprosthetic valve. This type of valve is made primarily from animal tissues. One example is the aortic valve “borrowed” from a pig. Another example is a valve that is made from “fabric” borrowed from the pericardium of the cow. These valves have the advantage that blood clots are much less likely to form on their surface, so patients do not need to take blood-thinning medications (other than, perhaps, aspirin) in the long term. They have the disadvantage that they do not last forever. Young patients who receive these valves may need to have the valve re-replaced because it “wears out” at some point. The major manufacturers include Medtronic, St. Jude Medical, and Edwards Lifesciences.

Aortic replacement. When the aorta is enlarged in the setting of BAV, there are a couple possibilities: the valve needs to be replaced–or it doesn’t:

With valve replacement. When the aorta needs to be replaced along with the aortic valve, we call this procedure an aortic root replacement. This is a complicated operation technically and must be tailored very carefully to the patient’s specific situation. Options include:
- Mechanical valve conduit. Products are available that combine a mechanical valve attached to a Dacron fabric tube. This is used, as a unit, to replace the patient’s aortic valve and beginning portion of the aorta. The coronary arteries are re-implanted into the Dacron tube. Of the options listed here for aortic root replacement, this is by far the most common.
- Bioprosthetic valve conduit. This is not commercially available, but can be assembled in the operating room. The operation is like described above for the mechanical valve conduit.
- Medtronic Freestyle valve. This is a unique product that is a porcine aortic root that can be used to replace the human patient’s aortic root, like the other operations above.
- Ross procedure. This is the most technically complicated option. The patient’s aortic valve and beginning portion of the aorta are removed. The patient’s own pulmonary valve is removed and then used to replace the aortic valve and beginning portion of the aorta. The coronary arteries are re-implanted into the pulmonary valve trunk. A cryopreserved pulmonary allograft (the pulmonary valve and trunk from a human cadaver) is then used to replace the patient’s pulmonary artery.
Without valve replacement. When only the aorta must be replaced, a Dacron fabric tube is used.

Valve repair. There is recent interest and experience with aortic valve repair–instead of replacement–for patients with BAV. These techniques are most applicable to situations in which there is regurgitation, rather than stenosis, of the valve and when there is also enlargement of the aorta. To help correct the regurgitation, the cusps of the patient’s valve leaflets can be tailored, with the valve leaflets left in place. Then, a Dacron fabric tube can be used to reconstruct the aorta, in a so-called valve-sparing aortic root replacement. This procedure has the particular benefit that no artificial valve (with the disadvantages described above) needs to be used. The potential downside relates to durability. Questions currently remain about how long such repairs will last and whether patients might require re-operation at some point in the future. This valve repair option is one that might best be pursued at a center that specializes in this problem.

After operation

The recovery from heart surgery can be hard to predict for any given patient, but we know that young otherwise healthy patients tend to do well. Most patients spend about a week in the hospital after operation and then are able to go home.

Early after operation, and for perhaps the first month, we typically limit activities that place stress on the shoulders and sternum. This gives a chance for the sternum, which was split during the operation, to heal completely. So for that first month, we usually advise no driving, lifting, pulling, pushing, reaching, etc. During that first month we recommend ample walking as the best form of exercise. After the first month, patients are generally allowed to return gradually to all of their previous activities.

Patients who’ve had aortic valve replacement and/or replacement of the aorta will require life-long monitoring by their doctor, with periodic echocardiogram and/or chest CT scanning. Over time, there will be some patients who develop problems with the prosthetic heart valve or enlargement of some portion of the aorta (that hasn’t already been replaced) that requires operation.

Athletes will ask when they can return to their sports. Consensus guidelines from the Proceedings of the 36th Bethesda Conference recommend:

Athletes with mechanical or bioprosthetic heart valves may participate in low and moderate intensity sports
Athletes who are taking blood-thinning medications should avoid sports where bodily injury, with potentially life-threatening bleeding, might occur

The first recommendation does not include the endurance sports. The truth is that there is not much scientific information about what happens to such athletes if they do return to endurance sports. At issue are the potential long-term effects of repeated episodes of high heart rate and high blood pressure that accompany intense exercise. Unanswered questions include: Can a bioprosthetic valve wear out more quickly than expected? Does the (unreplaced) aorta enlarge over time? If so, how quickly? Do medications like beta-blockers limit any potential harm? We just don’t know.

Yet I’m personally aware of a good number of athletes who’ve returned to endurance sport after operations of various sorts for BAV, presumably after discussion with their doctors. Athletes should have detailed discussion with their doctors about any prudent limitations to exercise after operation and settle on a mutually agreeable plan.

George W. Bush Gets a Stent

August 21, 2013 By Larry Creswell, MD 1 Comment

We learned from news reports earlier this month that former President George W. Bush was treated with a coronary stent for a blockage in a coronary artery that was discovered during his annual medical check-up. Of course, a great many Americans are treated each day for coronary artery disease (CAD), but Bush’s case draws my attention not only because he’s the former President but also because he’s known to be physically active, especially with cycling.

Bush’s Medical History

The fine details of Bush’s most recent health matters haven’t been made public, and might never be. But we know that while President from 2001 to 2009 he enjoyed comprehensive medical check-ups performed at the Bethesda Naval Medical Center. Each year, short statements were issued by the White House that summarized the President’s health. We can take a look back at some of that reporting.

Before taking office, the President received annual medical check-ups from Dr. Kenneth Cooper at the Cooper Clinic in Dallas, Texas. We know that, at the time he took office in 2009, he had no heart problems and no significant family history of heart disease. He occasionally smoked a cigar, did not drink alcohol, and had typical caffeine intake in the form of diet soft drinks and coffee.

From his examination at age 58 in 2004, we know that: he was 6 feet tall, weighing 200 pounds; his body fat was 18.25%; his resting heart rate was 52 and the blood pressure was 110/60; and the total serum cholesterol level was 170 mg/dL, with a decrease in the LDL (bad cholesterol) and increase in the HDL (good cholesterol) from one year previously. He was noted to have mild calcification of the coronary arteries (presumably based on a screening cardiac CT scan) and both aspirin and a cholesterol-lowering agent were prescribed. At the time, he was running 7 1/2 minute miles on the treadmill and was cycling several times per week.

In 2005 we learned that the President’s weight had decreased by a few pounds and the blood pressure and resting heart rate remained low. He underwent an exercise treadmill test that was normal and his doctors concluded that he was at “very low risk of coronary artery disease.” By 2005 Bush had given up running because of difficulties with knee pain, but continued to be active with cycling and weightlifting.

In 2006 at age 60 he was noted to have an EKG without worrisome abnormalities and a normal stress echocardiogram. Doppler ultrasound studies of the arterial blood supply to the legs was normal and a screening ultrasound of the abdomen showed no evidence of abdominal aortic aneurysm. Laboratory values included: total cholesterol 174 mg/dL, HDL 60 mg/dL, LDL 101 mg/dL, triglycerides 61 mg/dL, and normal values for C-reactive protein (CRP) and homocysteine. Interestingly, it was reported that he was taking no prescription medications despite the 2004 statement about the recommendation for a cholesterol-lowering agent. On the basis of the available information, the President was thought to have “low” to “very low” coronary artery disease risk.

The Coronary Stent

As we all know, Bush left office in 2009. Since then, his medical affairs have been private. So, fast forward to 2013….

We know that Bush went recently for his annual medical check-up at the Cooper Clinic and the following day at Texas Health Presbyterian Hospital was treated with a coronary stent for a blockage in a coronary artery that had been discovered duringn his evaluation. The details have not been made public, but it’s probably fair to assume that he underwent a stress test that was abnormal and that coronary arteriography was organized for the following day, with implantation of the coronary stent at the same setting.

The fact that Bush was treated with a stent for the coronary artery blockage has created a bit of a stir in the medical community. For those who are interested you can read more at:

“Did George W. Bush really need a stent?,” an article by Larry Huston in Forbes.

“The George W. Bush stent case: An incredible teaching opportunity on the basics of heart disease,” a blog piece by Dr. John Mandrola.

“Heart stents still overused, experts say,” an article by Anahad O’Connor at NY Times Well.

Basically, the controversy revolves around the appropriate treatment for asymptomatic patients–those without chest pain, heart attack, etc.–or those with so-called “stable” symptoms–for instance, chest pain with exertion–who are found to have blockage(s) in the coronary arteries. In truth, there has been no public reporting on whether or not Bush had any such symptoms, either with exertion or at rest. And there has been no updated reporting on Bush’s physical activity level or other relevant risk factors for CAD. But information from the best scientific studies suggests that asymptomatic patients and those with “stable” CAD fare no better, with respect to heart attack, stroke, or death, with a stent than without, so long as the best possible medical therapy is provided.

At any rate, this controversy will be one for our community of heart professionals to discuss and sort out.

What Can We Learn?

From the athlete’s perspective, though, Bush’s story reminds us of the importance of coronary artery disease as we age, even if we remain physically active. A few thoughts….

1. The discovery of CAD is almost always a surprise….particularly for an athlete. Nobody is immune from this disease, even if remaining physically active helps guard against it.

2. There is a set of well-established risk factors for CAD. I’ve talked about this issue previously here at the blog. Let’s remember that there are some risk factors that, unfortunately, can’t be modified: increasing age, being male, and having a family history of early CAD. Other risk factors are under our control: obesity, high blood pressure, smoking, abnormal serum cholesterol and lipid levels, diabetes, and physical inactivity. Adult athletes should know where they stand with respect to these risk factors and work to improve any that can be modified favorably. An ongoing relationship with a healthcare provider will offer the necessary framework for this. Periodic measurement of the blood pressure and testing of the serum cholesterol/lipid levels every 5 years are recommended.

3. Our personal situation with CAD will likely change over time. The process in which plaque builds up in the coronary arteries can begin early in our lives. But this process is often progressive as we age. That’s why we say that increasing age is a risk factor. Bush’s story illustrates just how this can happen. In 2004-2006 he had very favorable clinical and laboratory data regarding his risk of CAD, including a normal stress echocardiogram in 2006. Yet today we know that an important blockage had formed, or more likely progressed, in the interim. It’s important, then, to periodically re-visit our circumstance with CAD.

4. Warning signs are important. Important blockages in the coronary arteries often lead to symptoms of angina–chest pain/discomfort or perhaps difficulties with breathing. When angina occurs with exertion, we call it exertional or stable angina. When angina occurs at rest, we call it unstable or rest angina. Either form of angina should prompt timely evaluation. That evaluation may take the form of stress testing or coronary arteriography to look for blockages in the coronary arteries. Unfortunately, there are some patients whose first sign of trouble is a heart attack, or myocardial infarction. This can occur in athletes and non-athletes, alike.

Related Posts:
1. Coronary Artery Disease: The Essentials
2. Two Stories, Two Endings, a blog post about endurance athletes and CAD.
3. In the News: Coronary Plaque Build-up in Marathoners

In the Medical News: Athletes and ICD’s

May 23, 2013 By Larry Creswell, MD Leave a Comment

In this week’s edition of the American Heart Association medical journal, Circulation, Dr. Rachel Lampert and her colleagues from Yale University School of Medicine published a report entitled “Safety of Sports for Athletes with Implantable Cardioverter-Defibrillators.” This report is important because it is the most careful description yet of what happens to athletes with these devices who continue to participate in sports.

Background

Internal cardioverter-defibrillators (ICDs) are sophisticated medical devices that are implanted near the heart, usually with leads (electrodes) that are threaded into the heart, and are designed to provide a shock in the event that its owner’s heart develops a fatal arrhythmia. You can read more about the ICD and view some diagrams that show how these devices are implanted in an article by the National Heart, Lung, and Blood Institute (NHLBI).

These ICD devices are a treatment for patients who have had–or who are at high risk for–sudden cardiac death (SCD), the abrupt onset of a fatal arrhythmia. From the new report, the list of reasons that subjects had received an ICD was pretty long, and included: long Q-T syndrome, hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular dysplasia (ARVD), coronary artery disease (CAD), idiopathic arrhythmias in a structurally normal heart, dilated cardiomyopathy, congenital heart disease, and valvular heart disease, among others.

Conventional wisdom has held that athletes with an ICD should be restricted to low-intensity sports such as golf. Consensus guidelines for athletes with an ICD are summarized in the Proceedings of the 36th Bethesda Conference on Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities. These cautious guidelines stemmed primarily from a concerns about 1) the efficacy of the ICDs to deliver a shock appropriately during intense exercise and 2) the possibility of damage to the device or leads during physical contact that might render the device ineffective.

Interestingly, in 2006 these same investigators conducted a survey of Heart Rhythm Society members and found that more than 40% of respondents reported having at least 1 athlete patient with an ICD who was continuing to participate in competitive or vigorous sports despite recommendations to the contrary.

The Study

In 2006 the investigators started a registry that would enroll and follow athletes with an ICD who were known to be continuing to participate in sports of moderate or high intensity. Often, this would be a situation where the athlete patient was participating in these sports despite their doctor’s recommendation not to do so. The investigators eventually enrolled 372 athletes. Of these, 211 were enrolled by medical institutions in the United States (41) or Europe (16). The remaining 161 were self-enrolled–that is, the athlete contacted the Yale investigators directly and asked to be enrolled. The median age was 33 years and 33% were female.

The median follow-up was 31 months. Twenty-one patients did not complete the study: 9 were lost to follow-up, 6 withdrew, 4 stopped exercising because of worsening heart problems, and 2 died.

The important findings were:

1. There were no occurrences of death, resuscitated cardiac arrest, or arrhythmia- or shock-related injury during sports.
2. Thirty-six individuals (10% of the athletes studied) had shocks during practice or competition. Of these, 30% stopped participating in 1 or more sports as a result.
3. Twenty-nine individuals (8% of the athletes studied) had shocks during other physical activity. Twenty-three individuals (6% of the athletes studied) had shocks at rest.
4. There were 13 definite and 14 possible lead malfunctions and no generator malfunctions. This lead malfunction rate is similar to non-athlete populations.
5. There were no significant athlete injuries stemming from shocks during exercise.

My Thoughts

Creating this ICD registry was a great idea.

This report offers the most detailed look yet at what happens when athletes with an ICD continue to participate in sports. The results provide a basis for thoughtful conversation between physician and athlete-patient regarding the risks of continued sports participation with an ICD.

Although a small number of athletes experienced both appropriate and inappropriate shocks, it should be reassuring that the ICDs terminated all episodes of ventricular arrhythmias and there were no athlete deaths. Although it certainly remains a possibility, it is fortunate that there were no significant injurties to athletes receiving a shock during exercise. This is an area, though, where due caution is still well-advised because circumstances could be unforgiving for even a brief period of unconsciousness in activities such as cycling, rock climbing, swimming, etc. Lastly, the results suggesting that generator and lead malfunction are uncommon, even among athletes who were participating in sports that involve physical contact should allay fears that the ICD could be rendered inoperative during sporting activities.

My congratulations to Dr. Lampert and her colleagues!

Mitral Valve Prolapse

March 18, 2013 By Larry Creswell, MD 43 Comments

Mitral valve prolapse (MVP) may well be the most common problem with the heart valves. This condition may be present in as many as 5% of the general population. Women are affected more often than men.

Recall that the mitral valve sits between the left atrium and the left ventricle, the main pumping chamber in the heart. And remember that the mitral valve closes while the left ventricle contracts, allowing only one pathway for blood to exit the heart–through the aortic valve and into the aorta.

MVP is a problem with the valve closing properly. The mitral valve consists of 2 leaflets–an anteior (front) and posterior (back) leaflet. The diagram above shows the normal situation as well as the prolapse situation, where (in this case) one of the leaflets does not close properly.

There are several potential causes, including rheumatic fever, inherited conditions such as Marfan’s syndrome, infection (endocarditis) of the heart and valves, and as a consequence of coronary artery disease and heart attack. But the most common cause is simply wear and tear, a problem that we call degenerative disease of the valve.

Symptoms may include chest pain, fatigue, and palpitations. Importantly for athletes, the chest pain is most often unrelated to activity.

Patients with MVP often have a classic sound–a mid- to late systolic click–that can be heard with the stethoscope. Nonetheless, this condition is most often identified by an echocardiogram that was obtained to sort out the cause of a patient’s symptoms. The ultrasound pictures show the improper closure of the mitral valve and may show any associated problems such as leaking (regurgitation) of the valve.

We generally think of MVP as a benign condition–that is, one that has few harmful effects other than the symptoms.

Medical treatment with beta-blockers–medications that slow the heart rate and reduce the blood pressure–may alleviate the symptoms. Current guidelines suggest that individuals with mitral valve prolapse do not need to take antibiotics to prevent infections (endocarditis) of the heart and heart valves.

If regurgitation becomes moderate to severe, because of continued degeneration of the valve over time, surgical repair or replacement of the valve may be necessary.

Recommendations for Athletes

Consensus recommendations for athletes come from the Proceedings of the 36th Bethesda Conference.

Athletes with MVP can participate fully if they don’t have: a history of syncope (blacking out); repetitive arrhythmias; severe regurgitation of the valve; reduced heart function; a history of stroke or transient ischemic attack (TIA); or a family history of sudden death related to MVP. Athletes with any of those additional problems should receive further evaluation and should participate only in low-intensity sports.