What Is The Target Heart Rate For Exercise For A Quadruple Bypass Patient?
Thank you for your query.
Since you could discover the major blockages in your coronary arteries before an attack and since you could successfully get a bypass surgery done, I think that your overall prognosis is good.
Walking is a very good form of exercise for you. Since it is 7 weeks post surgery, and assuming that your recovery has been good with all wounds healing properly, you should start walking.
You can walk at your own pace. Start slowly and walk around 5-10 minutes per day. Once you are comfortable with this, you can build up further.
Your target should be to walk for a minimum of 30 minutes per day. You should walk every day of the week preferably.
At the minimum, you should walk at least 4 days per week.
The speed at which you walk is not important, rather, the time spent on walking is.
Do not aim at achieving any specific target heart rate.
At this juncture, it is important not to increase your heart rate too much.
Be careful when climbing up stairs or walking up an incline. Be slow, take your time and do it slowly.
If at any time you feel any discomfort in the chest, dizziness, breathlessness or fatigue, you should stop, take rest and get back to your cardiologist for re-evaluation.
Since your sternum (bone in front of chest) has been opened for the surgery, it will take around 12 weeks time for it to heal completely.
It is wise not to do anything that would put pressure on that bone, especially lifting weights, bending and straining, etc.
In addition to the medicines that you have listed, you should also be on aspirin with or without clopidogrel. Please discuss with your treating physician.
I hope I have been able to answer your query. Please feel free to get back to me if you have any unresolved issues.
Regards,
Dr RS Varma
when u say "it's important not to increase heart rate too much," can you be more specific--to what percentage of my XXXXXXX heart rate should I go, assuming XXXXXXX is 220 minus age.
thank you.
Thank you for following up>
Coreg is carvedilol, which is a combined alpha and beta blocker and is a good drug to prevent heart failure and improve the pumping of the heart. There are anti-arrhythmic properties too.
Aspirin is an anti-platelet and is useful to prevent further acute coronary syndromes by preventing the platelets from adhering together inside the blood vessel and causing a clot to form within the coronary artery.
220 minus the age is a formula used to calculate the target heart rate that you should achieve when you are doing a treadmill test.
When you reach this rate, your heart muscle function is at or near its maximum capacity. At this level of exercise, if there is no evidence of ischemia in the ECG, it is assumed that there is no functionally significant ischemia.
You cannot use this formula for calculating the level of exercise. You can to to after a bypass surgery. Another factor is that the carvedilol will prevent, to a degree, an exercise induced increase in the heart rate.
There are other factors that determine the heart rate response during exercise like anemia, physical conditioning, stress levels, anxiety, any other co-existing medical condition, etc.
What you should note is that, for you as a post-bypass surgery individual, the resting heart rate should be near 60/minute. A 25% increase from this resting heart rate during exercise is usually safe. However, this is just a consensus of opinion. There is a lot of individual variation, and ultimately, you have to limit yourself depending on your own exercise capacity, symptom levels and common sense. You will find that while a certain level appears comfortable now, as days and months pass, a higher level can be attained without any distress. There are post-surgery rehabilitation centres that offer structured exercise protocols and regimens individualized to your needs. Your treating cardiologist will be able to advise you on that.
Hope I have answered your query.
I wish you all the best for a healthy life.
Regards,
Dr RS Varma
4/11/11. Visited my internist with (what turned out to be) angina. She did a resting EKG which came back normal.
4/20. Did stress echogram. That picked up probable CAD. Ejection fraction was 62.
4/27. EKG and catheterization. EKG picked up "inferoposterior infarct, age indeterminate" but I was not told about this; I was told "your heart is strong, no heart atttack." XXXXXXX showed multi-vessel disease, including 100 per cent occluded RCA.
6/2. CABG Surgery (quadruple). After the surgery, was told no visible damage to the heart, and heart functioning normally. The surgeon reiterated this yesterday when I contacted him. The written report of the procedure says the following:
Pre-procedure. Left Ventricle inferior wall is mildly hypokinetic. All remaining score segments are normal. Visual ejection fraction 45 +/- 5.
Post-procedure. The left ventricle is normal in size and function. EF 45-50%. The right ventricle is normal in size and function.
SO--
1. What do you make of all of this? How would you evaluate my current heart function and overall prognosis, given that there may have been a silent MI at some point. Does the fact that the Ejection Fraction went from 62 to 45-50 mean anything significant? What do you make of the fact that the EKG on 4/11 was normal, but after that, all the EKGs pick up an "old" MI? The surgeon yesterday told me EKGs can be hyper-sensitive. . .how true is this?
2. Given that I was given inaccurate info by a (different) cardiologist, my current cardiologist says we could do a stress echo now. Should I? Or should I wait, because meds/exercise may improve heart function over next several months? My internist says current meds etc will improve heart function--is this true?
Thank you.
Thanks for the follow-up.
I would like to see the 2 ECGs before commenting on them. It is possible that you might have had a minor attack somewhere in between. I would like you to use the file upload feature of this site and upload the two ECGs so that I can give you a more specific reply.
I would also like to know whether the EF mentioned in your stress echo report was the baseline EF or EF at maximum stress.
Was a troponin test or any other test for cardiac enzymes done at any point of time?
In the absence of diabetes, autonomic neuropathy and some other rare disorders, a truly silent MI usually means a very small infarct.
Also, the method of estimation of EF (visual, M-mode, 2D, 3-D, etc) partly influences the value, especially if there was a regional wall motion abnormality.
However, since you have had a coronary angiogram and subsequently, a successful CABG surgery, your overall prognosis is good. It is usual, in the immediate post operative period to note paradoxical septal motion in the echo. This has to be factored in while estimating the EF. A more accurate EF measurement will have to wait till at least 6-12 weeks have passed.
Since the surgeon has not noticed any visible damage to the heart and since all the blocked arteries have been "by-passed", there is a good chance of your cardiac function improving with time. The lisinopril and carvedilol that you are currently taking will help to improve the LV function.
I do not think that a stress echo is needed at this point of time, since you do not have any symptoms at present and the blocks have just been by-passed. The cardiac muscle needs time to heal. Let Time, the great healer, work its magic and along with a healthy lifestyle, appropriate diet, regular exercise and necessary medicines, there is every chance of good improvement.
I hope I have clarified your doubts. Please do upload the ECGs so that I can analyze them and see if there is any evidence of an infarct. If there is a post-surgery ECG, you could upload that as well.
Regards,
Dr RS Varma
Here is the stress echo report 4/20:
Transcription Echocardiography Report: Stress Echo
Westlake Family Health Center
Date of service: 4/20/2011 2:06:41 PM
Accession #: 0000^SDE
Ordering physician: XXXXXXX RICE XXXXXXX
Indication: chest pain
Technologist: Shaney Luic
Interpreting physician: XXXXXXX Reynolds MD
PATIENT:
Name: DR. XXXXXXX N HIRSCH
MRN: 0000
Age: 59 years
Gender: M
Height: 167.64 cm BSA: 1.82 m²
Weight: 71.22 kg BMI: 25.3 kg/m²
Heart rate 77 bpm
Blood pressure 124/80 mmHg
MEASUREMENTS:
Value Indexed Value
Max aortic dimension 3.1 cm 1.70 cm/m²
Left atrium diameter 3.6 cm (M-Mode)
Left atrial volume 35.7 ml (Area-Length) 19.6 ml/m²
LV ID (diastole) 3.3 cm (2D)
LV ID (systole) 3.0 cm (2D)
IVS, leaflet tips 1.0 cm (2D)
Posterior wall thickness 0.9 cm (2D)
LV stroke volume 37 ml (2D biplane)
LV cardiac output 3.0 l/min (2D biplane) 1.6 l/min/m²
LV end diastolic volume 60 ml (2D biplane) 33.0 ml/m²
LV end systolic volume 23 ml (2D biplane) 12.5 ml/m²
Ejection Fraction 62 % (2D biplane)
FINDINGS:
LEFT VENTRICLE
The left ventricle is normal in size.
Left ventricular systolic function is normal.
Baseline left ventricular diastolic function is consistent with abnormal
relaxation (stage 1).
Mitral annular lateral E/e': 4.9. Mitral annular septal E/e': 5.8.
Wall Motion:
Rest: All scored segments are normal.
Stress: The inferior wall is severely hypokinetic. All remaining scored segments
are normal.
RIGHT VENTRICLE
The right ventricle is normal in size.
Right ventricular systolic function is normal.
LEFT ATRIUM
The left atrial cavity is normal in size.
Pulmonary Veins:
The pulmonary venous pattern showed normal systolic flow.
MITRAL VALVE
The mitral valve is normal. There is trivial mitral valve regurgitation. The
average mitral E/e' ratio is 5.3.
TRICUSPID VALVE
The tricuspid valve is normal. There is trivial tricuspid valve regurgitation.
AORTIC VALVE
The aortic valve is normal. There is no aortic valve regurgitation. Tricuspid
aortic valve.
AORTA
The visualized aorta is normal in size.
Measurements - Mid ascending aorta 3.1 cm.
INTERATRIAL SEPTUM
The interatrial septum is normal.
INTERVENTRICULAR SEPTUM
The interventricular septum is normal.
STRESS ECHO
Peak HR 131 bpm. (81 % MPHR)
Peak BP 152 mmHg/76 mmHg.
The left ventricular cavity size is decreased with stress.
CONCLUSIONS:
- The exercise stress echo was positive for ischemia at 81 % of MPHR (8.6 METS).
There is ischemia in the territory of the RCA.
- The left ventricle is normal in size. Left ventricular systolic function is
normal. EF = 62 ± 5% (2D biplane)
- The right ventricle is normal in size. Right ventricular systolic function is
normal.
- There are no significant valvular abnormalities.
-- There appears to be hypokinesis of the base and mid inferior wall post
exercise at 81% MPHR.
Electronically signed by XXXXXXX Reynolds MD on 4/20/2011 at 3:10:38 PM
----
I spoke again to my cardiologist's office this morning, and they agree an echo right now isn't needed, they suggested doing one in 3 months.
I was aware and concerned about what was going on with my heart, so if the MI occurred between 4/11 (normal EKG) and 4/27 (note of past MI), then I'd bet it was in fact truly silent. The other possibility might be that the 4/11 "normal" EKG wasn't quite normal--I gather these things are not cut and dry. . .although I greatly trust my internist, and she looked at the graph itself.
Here is the report from the pre-cath EKG on 4/27--
EKG Severity - ABNORMAL ECG -
SINUS RHYTHM
normal P axis, V-rate 50-99
EARLY PRECORDIAL R/S TRANSITION
QRS area positive in V2
INFEROPOSTERIOR INFARCT, AGE INDETERMINATE
Q>35mS, T neg, II III aVF
--
Let me know if any of these numbers (such as troponin) tell you anythign or change anything. Thank you very much.
Thank you for your lucid reply.
From the serial recordings of ECG and stress echo, it is probable that you had a minor MI between 4/20 and 4/27. The earliest ECG was probably normal, as reported by your internist. This is also borne out by a negative troponin test done on 4/11.
In the stress echo on 4/20, there are no resting wall motion abnormalities, but stress has resulted in wall motion abnormalities in the inferior wall. This shows that there is probably sufficient blood supply at rest to keep that segment functioning normally, but a severe block exists that makes blood supply to the area deficient during stress (when there is an increased demand).
The next ECG on 4/27 has reported changes suggestive of an inferoposterior infarct. The term age indeterminate in most automated ECG analysis algorithms is used when the changes are NOT suggestive of an acute process, and at the same time, not really consistent with an old MI.
From these parameters, I would conclude that you had a critical, probably near-total occlusion of the RCA which had developed over many months or years. At some point between 4/20 and 4/27, it had become a complete occlusion. Since this event was a small acute process superimposed on a sever chronic pathology, it has gone by unnoticed. Since the chronic lesion has developed over many years, it is likely that collateral blood supply would have been recruited by the cardiac muscle. Though the acute event of complete closure has brought about ECG changes, the presence of collateral blood flow would have prevented you from noticing any severe chest discomfort normally associated with a heart attack. Also, I would assume that these collaterals would have kept much of the cardiac muscle alive, though not functioning optimally. This would mean that only a very small area of myocardium would have actually been completely damaged. Also, with the restoration of blood flow, this "hibernating" myocardium will improve in function over time, leading to an improvement in ejection fraction over time.
This would be my analysis based on your data. Since you have had a successful CABG, I think you should approach the future with a positive outlook. Continue your healthy lifestyle, nutritious diet, regular exercise and appropriate drugs as prescribed by your doctor. An echo may be repeated after approximately 3 - 6 months depending on your recovery. I am sure it will show a lot of improvement.
All the best!
Dr RS Varma