"THE HEART OF THE MATTER"
a special program of the National Emergency Medicine Association (NEMA)
(Return to Topic Page)
Guest: Dr. Elizabeth Gullette, cardio researcher, Duke Univ. Medical Center
Topic: Everyday stresses/cardio ischemia
Host/Producer: Steve Girard
NEMA: Thanks for joining us today. Today, were talking about how everyday stresses can affect heart patients...and the findings of a recent study that may have repercussions for most us in the areas of managing stress and keeping our heart fit. Our guest is Dr. Elizabeth Gullette of Duke University Medical Center....
GULLETTE: Well, the impetus of the study was actually sort of multifaceted. We were actually looking specifically at patients with coronary artery disease, first of all. And it had been shown in past research that myocardial ischemia, which is a temporary state in which there is an insufficient supply of blood to the heart...it had been shown that this state of ischemia is prognostic of negative outcomes, which means it predicts later heart attacks and things like that. So, its a bad indicator of disease...its an important thing to be following in patients with heart disease. It has also been shown in laboratory studies that both exercise and mental stress...or negative emotions, can cause ischemia to happen. But in studies that have looked at patients during daily life, its been a little less clear whats causing ischemia. It has been shown that ischemia is very common, but it really occurs during a variety of activities, both sedentary and active. So, this variability in ischemia, this sort of unexplained variability, was really what was driving us, because we thought that maybe it was changes in a patients mental state that was explaining some of the variations. And since we had seen in lab studies that mental stress did induce ischemia, we though it was logical that mental stress would be causing ischemia during daily life, so thats really why we did the study.
NEMA: Are there physical symptoms of ischemia?
GULLETTE: Not normally, and this has not always been known. theres something called angina pectoris, which is basically chest pain, and for a long time, it was thought that always ischemia, and that ischemia always occurred with chest pain. However, in studies using some of the newer technologies over the past 10 or 15 years, in which patients can actually be monitored in daily life, and they keep a record of when they feel chest pain, etcetera...it has been shown that oftentimes that ischemia occurs in the absence of any symptoms, or any pain, and this has been termed silent ischemia, or asymptomatic ischemia...and actually, in our sample, we found that the large majority of ischemic events were not associated with pain, and in fact, only about 2 percent of the events were associated with pain...so its largely asymptomatic.
NEMA: What was the experience like for the patients in this study?
GULLETTE: What we did was we had them come in in the morning, and they had been taken off any medication to prevent ischemia, so that their ischemia could occur naturally...and we hooked them up to whats called a halter monitor, which is basically a portable electrocardiogram, or EKG. So, this involved some electrodes on their chest and enables us to monitor their EKG constantly during the 24...or 48 hours of monitoring - 48 hours in our case...and changes in their EKG are indicative of ischemia. So, we had cardiologists go back and look at their EKG tapes, and anytime there was a certain type of change, it was noted as ischemia. So, we had them do...also in addition to being monitored with these portable EKG monitors, is to keep an ongoing diary. So, we gave them a small, pocket sized diary booklet, in which every page was the same, and it included a space for the patients to note what activity they were doing, as well as to rate themselves on five different emotions. Three of them were negative...they were frustration, tension and sadness, and two of the emotions were positive...and they were happiness and feeling in control. The patients would rate themselves on a scale from zero to 4. And the way that we kind of indicated to them that it was time to take a diary rating...or to enter a diary rating, was that we had them wear beepers, basically, which emitted a signal, an auditory signal, a beep...randomly...but an average of about 3 or 4 times an hour. So each time that the beeper sounded, they would enter a diary entry, so that we had this ongoing record of their activities and emotions throughout the day. And then we also had this ongoing record of their EKG activity. So, we were able to crosstabulate the diary entries with the EKG information to see any activities or emotions that preceded any changes in their EKG...or any ischemic events.
NEMA: How does ischemia build to a heart attack?
GULLETTE: Well, first of all, it does not always build up to a heart attack. And sometimes its a very slow, gradual process. People can have ischemia every day for years and years before they have a clinical event, such as heart attack or sudden death. But basically what is happening is that over time, this constant, recurrent lack of oxygen to the heart can impair the hearts functioning, and can also damage some of the heart tissue...in fact that is what a heart attack is. A heart attack is just a much more massive...scale ischemic event. So, basically the ischemia is more an indicator of the severity of the disease, and therefore of the probability of a more serious event, rather than necessarily a step always. But it is accumulative process over many years.
NEMA: What were the brightest spots in your results?
GULLETTE: Well, what we found ...while in the past, research had shown some association between mental stress or negative emotions and ischemia...we were able to show through our methodology, to actually show a temporal, a causal link...which really was what enabled us to call these triggers. So, theres that causal link of mental stress causing ischemia, in a temporal sequence...and also what was new in our study was that we were able to quantify the magnitude of risk...and in fact, we were a bit surprised at the level of risk. We found that the emotions, the negative emotions - tension, sadness and frustration actually carried a two to three fold increase risk of ischemia compared to not experiencing high levels of these emotions...and really that was comparable to moderate levels of activity in our sample...physical activity has been known for a while to cause ischemia. So, this is sort of in keeping with the risk of physical activity. Now, heavy physical activity carries a greater risk, but even moderate activity is about the level of these negative emotions.
NEMA: What techniques could be used to lessen the occurrence of ischemia?
GULLETTE: A couple things...one of course, is stress management...because if we can reduce these levels of frustration and tension, then that of course can potentially help. ...as well as interventions for things like sadness or depression and anxiety. Basically, all of these negative emotions which tend to increase arousal in the sympathetic nervous system in the body are thought to be associated with these ischemic events. So, if we can decrease the frequency of negative emotions overall, then thats definitely a step forward. On the other side of the coin is to increase physical fitness. So, regular exercise, which can help to sort of shore up the bodys cardiovascular system against these insults, can potentially be effective as well. So, its probably a combination of the two of exercise as well as intervention to decrease the negative emotions.
NEMA: Is that the next area of investigation for you...
GULLETTE: Well, we have actually been looking further at data from this study, and some of our intervention data...looking at how interventions such as exercise and stress management impacts ischemia. So that is one of the things well be looking at. In addition, well be starting...hopefully, in the next several months...which will extend this research, and allow us to look a little bit further at interventions and mechanisms...because one of the questions that remains unanswered is what exactly is going on inside the body that is really causing the ischemia to happen as a result of the negative emotions. For example, what neurochemicals, or what sort of mechanical things going on with the cardiovascular system, are responsible for the ischemia...so both the mechanisms and the interventions are something were looking at now.
NEMA: What should the healthy person get out of this information?
GULLETTE: I would emphasize that this is a fairly select population. They not only have coronary artery disease, but also have past evidence of exercise induced ischemia. So, I dont think its something that a healthy person needs to worry about as an imminent occurrence...that ischemias going to happen if they continue to be stressed. But I do think its important for everybody both with and without heart disease, to realize that there are obviously effects in the body of these negative emotions...and whether theyre seen in such dramatic ways as we have seen with heart patients...or in much more subtle ways, its still an important thing to remember that connection, and to be aware of stress and negative emotions in your life...and to take good care of your cardiovascular system...to prevent any of these effects.
NEMA: Our thanks to Dr. Elizabeth Gullette of Duke University Medical Center for being with us today.
SPOT: Small pages....big advice on parenting...from infants to teens. What to expect, emotionally and physically, as your child grows. How to develop positive discipline,how to deal with kids and TV, adolescent issues, drug education, fighting, single and step parenting...its all in the Little Book of Parenting, available through the National Emergency Medicine Association. Call 1-800-332-6362 for more information.
NEMA: Thanks for joining us for todays program. If you have any comments or suggestions, contact this station. Or visit our home page at: www.nemahealth.org/ ...for a look at transcripts of this or past programs, or to find out more about the National Emergency Medicine Association. Im Steve Girard at The Heart of the Matter.