Arm Exercise Tests Predict Outcome of Acute Ischemic Heart Disease
Posted: Friday, February 05, 2010
by Dr. Ron Blankstein
Chesapeake Nutraceuticals
I'd like to share with you a research study that may prove to be an alternative to a pharmacological stress test. This is a procedure where a drug is administered by IV to simulate exercise in individuals who cannot perform the stress test on a treadmill due to injury or physical limitation. The drug raises heart rate by dilating coronary arteries to increase blood flow. The following study provides information about a less costly and less invasive protocol.
St. Louis, MO – A study released from the Department of International Medicine, Washington University School of Medicine, St Louis Veterans Administration Medical Center, used exercise capacity of arm strength as a predictor of survival and mortality rate in response to myocardial infarction (MI) and acute ischemic heart disease. Results were published in the January 2009 issue of the American Heart Journal.
Traditionally, treadmill exercise testing and leg cycle ergometer work is used as the predictor, but patients with lower extremity disabilities such as amputation and orthopedic or neurological disorders cannot participate in this type of exercise testing. Since arm exercise stress tests seem to provide similar data, a group of veterans was isolated and referred for arm ergometer stress testing.
359 patients who were either unable or unwilling to participate in treadmill testing completed the study at St Louis VA Medical Center between November 1997 and November 2002. Each veteran fasted overnight and took just a ½ dose of insulin on the morning of the test, if they were on insulin. Beta blocking agents were withheld, but all other medications were taken as usual. Patients gave voluntary, informed consent to be tested.
A brief medical history was taken from each patient and a physical exam initiated, after which a 12-lead ECG (electrocardiogram) was taken as a baseline and repeated once per minute during exercise. A manual blood pressure reading was recorded every three minutes from the non-exercising arm and continued every two minutes once the exercise was complete.
Testing was conducted with the patient in a seated position next to a wall-mounted, electronically braked cycle ergometer. Exercise protocol included an increase in work rate of 50 to 200 kilopond-meters (kpm) every two minutes with total testing time of 5 to 12 minutes. End point of testing was determined by exhaustion and/or symptoms induced.
As a control, pilot testing was conducted on 5 young, healthy sedentary subjects (4 men, 1 woman) aged 28 ± 7 years. Comparative values were then determined for oxygen uptake and maximal heart rate.
The participants, 354 men and 5 women, were followed for 63 ± 24 months from the date of the stress test until December 31, 2006. There were 98 deaths (27%) during the follow-up period as well as 33 MIs (9%). 41 individuals (11%) underwent coronary revascularization with 11 deaths (27%) among those 41 patients.
The average age of the participants in the study was 63 ± 11 years. Resting systolic and diastolic blood pressure was much the same in both survivors and non-survivors, but resting heart rate was somewhat elevated in the patients who died.
Arm exercise capacity proved to be a primary predictor of survival rate for overall ischemic heart disease but was not a predictor of MI or coronary revascularization. The average peak arm exercise work rate among survivors was 463 ± 173 kpm while non-survivors tested at a general rate of 340 ± 155 kpm.
"Our results provide evidence that arm ergometer stress testing may provide prognostic and clinical information nearly equivalent to that reported in the literature for treadmill or leg cycle ergometer exercise," reported the research team. Additional studies would be justified to determine the viability of using arm exercise as an alternative to pharmacologic testing in patients with lower extremity disabilities.
This information is provided for educational purposes and is not intended to diagnose, treat, cure or prevent disease.
Source:Traditionally, treadmill exercise testing and leg cycle ergometer work is used as the predictor, but patients with lower extremity disabilities such as amputation and orthopedic or neurological disorders cannot participate in this type of exercise testing. Since arm exercise stress tests seem to provide similar data, a group of veterans was isolated and referred for arm ergometer stress testing.
359 patients who were either unable or unwilling to participate in treadmill testing completed the study at St Louis VA Medical Center between November 1997 and November 2002. Each veteran fasted overnight and took just a ½ dose of insulin on the morning of the test, if they were on insulin. Beta blocking agents were withheld, but all other medications were taken as usual. Patients gave voluntary, informed consent to be tested.
A brief medical history was taken from each patient and a physical exam initiated, after which a 12-lead ECG (electrocardiogram) was taken as a baseline and repeated once per minute during exercise. A manual blood pressure reading was recorded every three minutes from the non-exercising arm and continued every two minutes once the exercise was complete.
Testing was conducted with the patient in a seated position next to a wall-mounted, electronically braked cycle ergometer. Exercise protocol included an increase in work rate of 50 to 200 kilopond-meters (kpm) every two minutes with total testing time of 5 to 12 minutes. End point of testing was determined by exhaustion and/or symptoms induced.
As a control, pilot testing was conducted on 5 young, healthy sedentary subjects (4 men, 1 woman) aged 28 ± 7 years. Comparative values were then determined for oxygen uptake and maximal heart rate.
The participants, 354 men and 5 women, were followed for 63 ± 24 months from the date of the stress test until December 31, 2006. There were 98 deaths (27%) during the follow-up period as well as 33 MIs (9%). 41 individuals (11%) underwent coronary revascularization with 11 deaths (27%) among those 41 patients.
The average age of the participants in the study was 63 ± 11 years. Resting systolic and diastolic blood pressure was much the same in both survivors and non-survivors, but resting heart rate was somewhat elevated in the patients who died.
Arm exercise capacity proved to be a primary predictor of survival rate for overall ischemic heart disease but was not a predictor of MI or coronary revascularization. The average peak arm exercise work rate among survivors was 463 ± 173 kpm while non-survivors tested at a general rate of 340 ± 155 kpm.
"Our results provide evidence that arm ergometer stress testing may provide prognostic and clinical information nearly equivalent to that reported in the literature for treadmill or leg cycle ergometer exercise," reported the research team. Additional studies would be justified to determine the viability of using arm exercise as an alternative to pharmacologic testing in patients with lower extremity disabilities.
This information is provided for educational purposes and is not intended to diagnose, treat, cure or prevent disease.
Arm exercise testing predicts clinical outcome", American Heart Journal, Vol 157, Issue 1, January 2009, Pages 69-76, Nasreen A. Ilias, Hong Xian, Cindi Inman, Wade H. Martin III
© 2009 Chesapeake Nutraceuticals
This Article has been viewed 518 times. (Not updated in real-time.)
No comments yet.We want your comments! If you can read this, you don't have javascript enabled, so you can't use this comment system. Please enable javascript.