Stress Echo

[sciman]

I talked my cardiologist into doing a stress echo on me to see if there is a big difference between my resting ejection fraction and my ef while exercising. My hope was that a big difference might show that my heart really isn't as bad as my resting ef indicates (46%). My reasoning is that I feel very good when I exercise so that may be a sign that my low ef is more an adaptation to exercise than a disease. Since asking him to do that some months back I've experienced some new symptoms (mild dizziness) and I think I'm just in denial. I think my ability to exercise is more about the conditioning of my body than it is the efficiency of my heart. So now I'm beginning to think that paying for a stress echo is probably just a waste of money.  

[kenkeith]

Exercise tolerance based on age is a factor for determining expectations, but there are degrees of fitness within an age group that a stress test measures.... That requires a point of reference from which measurements may be made;  something that serves as a standard by which others may be measured or judged; a standardized test that serves as a basis for evaluation or comparison. That would be the Bruce protocol or some other stress test protocol.  I'm sure you recognize that, and I am surprised a tech lacks the knowledge or understanding.  May be a communication problem as you state.

[sciman]

So I had my stress echo yesterday. They did a quick resting echo (had one done in August) before doing the stress echo.Took a quick glance and it was the usuall lazy looking contraction and she seemed to think it hadn't changed much just "eyeballing it".I was excited about having a test done that might define my exercise limits in terms of the met units. So the technician turns out to be fairly clueless of met units. Her only comment was that they determine exercise tolerance by age and gender, wow, totally clueless or perhaps I miscomunicated. So I do the test and make it to level 5 (out of 6) before my heart rate gets to 157 (16 minutes). I felt pretty good and could have gone a bit longer. The cardiologist will explain the results next week. I'm thinking that I've got to set my exercise boundaries very low because my muscles seem very well conditioned while my heart is probably doing too much. Bottom line is I can't base my exercise limits on how I feel when I exercise because my heart conditioning is so far behind the rest of my body.

[kenkeith]

Reasons for getting a stress test: A stress test is performed to determine causes of chest pain, the exercise capacity of the heart, appropriate exercise levels in those beginning an exercise program, and to identify rhythm disturbances during exercise. There may be additional reasons that your health care provider requests this test.  Your wish to learn of your heart's functionality with exercise and the degree of exercise for the most benefit with little risk is a reason doctors ask for a stress test.

The stress test will determine your MET level that is safe based on the monitored
ECG heart rate, blood pressure, and stress echocardiogram includes the following steps:

A resting echocardiogram will be done first. (Your EF, vital signs, etc.)
You will exercise or be given medicine until you reach the target heart rate. This helps reveal how your heart works when you are active.
Your blood pressure and heart rhythm (ECG) will be monitored throughout the procedure. If you are dizzy or experince discomfort the test will be terminated.  Otherwise your test will continue until you reach a stable heart rate target
Ultrasound images will be recorded during the procedure. Another echocardiogram is taken immediately after your target heart rate has been reached.

METs are crossed reference to gain knowledge of an individual physical capabilities, for instance, can the patient survive with some probabilty of success a serious surgical operation?.  If I remember correctly someone who has a MET of 4 probably could not survive a operationt, and 7 METs is the minium for a successful operation.  MET is a measurement of the heart's fuunctionality and how much exercise safely and beneficially.

[sciman]

Thanks for sharing your knowledge. I actually am more interested in my LV function than I am my conditioning. But I also need to know if I'm overdoing the exercise. That would be a great reason to get the test. I started running 3-4 miles in the morning and noticed that it tends to offset the sluggish feeling of my meds/cardiomyopathy (hopefully more meds than cardiomyopathy). On the other hand I was concerned that this might be too much exercise even though I was staying within the 30-40 minutes/5xwk boundary set by my cardiologist.

[kenkeith]

What you seem interested in is how well does the system compensate when there is impaired left ventricle functionality and the measurement thereof.  That is what METs dispensed will do.  For instance you have well-conditioned muscle...for a given task that requires rigorous expediture of respiration, heart to supply blood/oxygen to the skeletal muscles, vital organs, etc.  there will be a demand for oxygenated blood.  There are 2 ways to adequately meet the given task, and that is to reduce demand or increase supply for a given system.

Because supply is limited by an impaired left ventricle EF, the demand side of the supply=demand equation needs to be reduced.  That reduction can be met with medication to dilate vessels if necessary (a healthy person may have good vascular functionality and not need meds), volume of blood should be reduced if necessary, etc. and good muscle tone...requires less oxygenated blood and demand is reduced as measured by METs. A well-compensated individuals requires fewer METs for a given task therefore the individual is able to increase exercise workload.

[sciman]

Thanks for your input. The thing I'm wondering is to what degree that stress test measures your heart's efficiency as opposed to the ability of your muscles to run on what the heart's dishing out. In other words you could have a low ejection fraction and do reasonably well simply because you have highly conditioned muscles. With the stress echo they are also looking at the heart directly as you exercise. ;

[kenkeith]

Most stress tests involve the Bruce treadmil protocol  You can get idea how well you are conditioned if you have access to a treadmil or bicycle that measures METs (metabolic equivalent tasks)..

For example, when you ride a bicycle at 12 miles per hour, you are exercising at about ten METS or 10 times the amount of energy that you use during sleep. That’s the same as running a 10-minute mile, playing racquetball competitively, jumping rope at a moderate pace or playing in a soccer game.

Ten METs is equivalent and the expected measurement after a successful by-pass.  Thirteen METs is very good and expected for a well-conditioned individual. If you can sustain the given METs for 30 minutes and your heart rate is 220 minus your age, and blood pressure is not extremely high, you will have an idea how well your heart is functioning.


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[NTB]

why not find some discussion groups of bicyclers, runners, etc and see if you can find anybody like yourself

[banglamom]

I've wondered that too.  Now, can I not exercise because of my heart or because it's been so long since I exercised.  

2 years ago.. when  was wearing an event moniter.. I had more of the rhythm problems like I always had, but they were caught on the moniter and now we knew whaat they were.  The cardiologist told me to hold of on whatever caused the rhythms- which was EVERYTHING.  Now, I've gone on a couple walks rather gingerly and done ok, but it is nervewracking.  

I tried to shovel the driveway in our recent snowstorm.  I went shovel, shovel, shovel... then felt like the whole world was getting dark very fast and DIZZY.  I stopped and leaned on my shovel and within a few minutes, it was like the lights were coming back on like using a dimmer switch.  Then, I started again.  After a few more shovels, I was on my way to passing out again.  Repeat.  I did this a few times until I decided maybe shoveling was not for me.  Mostly, the response was.. you did WHAT!

I take lots of meds to not let my heart run away and the depend on my pacemaker to drive the rhythms.  O think my heart wanted to go 200bpm, but the pacer will only pace me up to 130.  When the demand was higher than that, I started to see the lights go out.  I'm not fully sure what to do with it either.  Best of luck... I hope someone will steer me in what to do too.