heart

In the Medical News: Sports-Related Sudden Death in the General Population

July 29, 2011 By Larry Creswell, MD Leave a Comment

In a scientific article published online earlier this week by Circulation, Eloi Marijon and colleagues at the Paris Cardiovascular Center reported on “Sports-Related Sudden Death in the General Population.”

In recent years there has been a focus on sudden cardiac death (SCD) that occurs in young athletes who are participants in organized and/or competitive sports. There has been much less attention paid to SCD that occurs in athletes (of all ages) who are not part of organized or competitive sports–those who are undertaking so-called recreational sporting activities. The investigators have studied the issue of SCD in this second, much larger group of athletes.

This large, observational study examined the experience in France between 2005 and 2010. The experience included 169,742,000 age specific person-years of follow-up. The investigators considered 2 separate groups:

1. Young athletes, ages 10-35, who were competitive athletes, and

2. Athletes, ages 10-75, who were participants in recreational sporting activities (cycling, jogging, soccer, hiking, swimming, basketball, and others).

Overall, the incidence of SCD was 4.6 per million population per year (860 events total). While a small number of SCD events (50) were observed in the first group, approximately 94% of the SCD events occurred in the group of recreational athletes. If the same statistics were applied to the United States population, we might expect upwards of 4250 cases of SCD among recreational athletes each year.

In the group of recreational athletes with SCD, only 11.7% had a known history of cardiovascular disease or had more than 1 classic risk factor for coronary heart disease. The majority of victims in this group were regular exercisers.

The exact cause of death among the victims was determined for only a minority (24.7%) of the group. If a cause of death was identified, it was cardiac-related in 98%.

The vast majority (93%) of SCD events were witnessed, but bystander CPR was provided in only one third of cases. Survival among the athletes with SCD was very much dependent upon prompt CPR and defibrillation.

SUMMARY

The frequency of SCD among recreational athletes is probably much higher than previously thought. This issue deserves and probably will receive additional investigation. The information provided by this report should prompt or renew discussion about the availability of CPR and defibrillation (AED’s) at venues where recreational athletes participate in their sports.

Can Too Much Exercise Harm the Heart?

April 19, 2011 By Larry Creswell, MD 3 Comments

Check out my monthly column at Endurance Corner, where I discuss the potential for (too much) exercise over the long term to cause harm to the heart.

All things considered, this issue hasn’t been studied very well. I review some of the pertinent scientific studies that raise important questions in this regard. The findings are certainly preliminary and beg for more research.

In my mind, the health benefits of exercise are well understood, though. I wouldn’t stop exercising just yet!

In the News: Athletes and NSAIDs

March 2, 2011 By Larry Creswell, MD Leave a Comment

Last week, my column at Endurance Corner dealt with the topic of athletes and non-steroidal anti-inflammatory drugs (NSAIDs). A new study draws attention to the cardiovascular risks associated with these medications. I’d urge athletes to think twice about NSAIDs when they choose to take these medications.

Coronary Artery Disease: The Essentials

November 22, 2009 By Larry Creswell, MD Leave a Comment

For those of you who have been following along, we’ve talked briefly before about the problem of coronary artery disease (CAD) and illustrated the problem last week with the story of Jim Fixx. And I’ve mentioned previously that CAD is the most common cause of sudden death in athletes over the age of 40. Today, we’ll talk about CAD in a little more detail. This should provide the foundation for future discussions that we’ll have about the many aspects of maintaining heart health as we age.

To put the problem of CAD into some perspective, you should realize that this is the most important chronic medical condition that Americans face. In fact, CAD affects more than 13 million Americans today. It’s the leading cause of death in the United States, with nearly 1 person dying every minute from this condition.

The Anatomy

The heart, as you know, is simply a muscle….but one that is in constant motion, usually beating 60-100 beats each minute, or upwards of ~140,000 times each day. And like other muscles of the body, it requires a generous blood supply to furnish the needed oxygen to keep things going. As the aorta leaves the heart, to take blood flow to the rest of the body, the first 2 branches are the left and right coronary arteries….the arteries that supply blood flow to the heart muscle itself. The left coronary artery branches into the left anterior descending and the circumflex coronary arteries. We often say, then, that there are 3–not 2–important coronary arteries.

We use the term CAD to refer to the progressive (over many years time) narrowing of the coronary arteries, the arteries that supply the heart muscle with its blood supply. This process, called atherosclerosis, usually starts with fatty streaks on the inside surface of the coronary arteries, but over years’ time progresses to larger, more space-occupying deposits of various lipids. The situation is not much unlike a typical plumbing problem, where a pipe might become clogged with unwanted material, thereby limiting blood flow.

What problems does CAD cause?

Individuals with CAD often experience no problems until the narrowing in the coronary arteries becomes severe. When the arteries become narrowed to less than 25-50% of their original diameter, the reduction in blood flow to the heart muscle can produce symptoms. At first, the symptom might be chest pain or discomfort (that we call “angina”) or perhaps unusually severe shortness of breath with exertion. Any of these symptoms should be a warning sign….and prompt you to be evaluated by your physician.

The plaques on the inside of the coronary arteries can sometimes rupture, leaving a raw surface exposed to the bloodstream, and lead to the formation of a blood clot at that site. This can produce chest pain at rest (unstable angina) or even acute myocardial infarction (MI), the situation where there is irreversible damage to the heart muscle.

Who gets CAD? What are the risk factors?

Much time and effort has been devoted to understanding who gets CAD. As you can imagine, this is the starting point for figuring out how to prevent CAD. We’ve learned that there are a handful of so-called risk factors, indicators of how likely it is that an individual will develop CAD. Some of these risk factors can’t be changed, but others can be modified to help reduce somebody’s risk.

There are some risk factors that you simply can’t change. One such risk factor is age. Men over the age of 45 and women over the age of 55 are more likely than their younger counterparts to have CAD. Unfortunately for men, men are just more likely than women to have CAD. And lastly, a family history of CAD in close relatives is a risk factor. As you can see, each of these risk factors is beyond your control.

On the bright side, though, several risk factors are under your control….and should be paid very special attention as we age:

1. Obesity (or even just being overweight)

2. High blood pressure

3. Smoking

4. High levels of blood cholesterol

5. Diabetes

6. Physical inactivity (although I’ll bet that most readers here are active!).

We’ll cover these risk factors in greater detail in upcoming posts.

Diagnosis and Treatment

Most patients with CAD come to medical attention because of symptoms such as angina or shortness of breath. Many others come to attention because of acute MI. And, sadly, some come to attention because of sudden death….and an autopsy shows CAD.

A stress test (which can be done in a variety of ways) or a cardiac CT scan can indicate the likelihood of CAD. The diagnosis is established, though, with coronary arteriography….a test in which dye is injected into the coronary arteries and motion picture x-rays are made. This creates a roadmap of the coronary arteries and shows any blockages.

If blockages in the coronary arteries are not severe, patients can be treated with medicines. Patients with severe blockages can be treated with angioplasty and stenting (to push the blockages aside) or with coronary artery bypass surgery.

That’s CAD in a nutshell. Like I said, I hope that this information provides the necessary foundation for us to have more detailed discussions about various topics down the road.