Effects of exercise training on left ventricular performance and myocardial perfusion in patients with coronary artery disease

“…Measurement of left ventricular function and volume at rest and during exercise using radionuclide ventriculography has gained widespread popularity for the diagnosis of coronary artery disease [1,2], assessment of drug intervention [3][4][5][6], evaluating the effec tiveness of coronary bypass surgery [7], and studying physiological responses [8], Some investigators have also employed this tech nique to assess the effects of exercise training on ventricular function in healthy individu als [9] and patients with coronary artery dis ease [10][11][12], Despite the widespread use of this technique, there are only a few studies which have addressed the problem of vari ability of these measurements during rest and exercise [13][14][15], Even then, the variability was usually assessed over a relatively short period of time (less than 2 weeks) while many intervention studies often measured changes over much longer periods [3][4][5][6][7][8][9][10][11][12], Thus, the ability to discern the effectiveness of an inter vention over a long period of time is compro mised by not knowing the variability of the radionuclide ventriculographic measure ments. Therefore, this analysis was per formed to assess the individual variability of equilibrium radionuclide ventriculography in patients with stable coronary artery disease during rest and exercise over 1 year.…”

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confidence: 99%

Individual Variability of Radionuclide Ventriculography in Stable Coronary Artery Disease Patients over One Year

Jensen¹,

Genter²,

Froelicher³

et al. 1984

Cardiology

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To determine the individual reproducibility of radionuclide ventriculography over an extended period of time, 33 patients with stable coronary artery disease were studied at rest and during three stages of exercise on two occasions separated by 1 year. The individual interstudy variability of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume, and cardiac output was determined by calculating the mean and standard deviation of the difference between the individual studies (initial – 1 year). Despite high correlations between an EF measured at study 1 and study 2 of 0.96 at rest and 0.87 during maximal exercise, the individual interstudy difference was 0.01 ± 0.04 and-0.02 ± 0.09, respectively. The correlation of percent change in EF from rest to maximal exercise was 0.49 and the individual interstudy differences was -1.2 ± 19%. Correlations of the EDV were 0.81 at rest and 0.72 during maximal exercise while the individual difference was 0.7 ± 38 and-0.8 ± 49 ml, respectively. Considering two standard deviations as the confidence limits for a true change, an EF change of 8 EF units (0.08) at rest and 18 (0.18) during exercise, and EDV changes of approximately 100 ml are needed in an individual to state with confidence that the observed difference between the two studies are true changes and not the result of technologic variability. Because of the large individual interstudy variability in EF and volume measurement, caution must be taken in assuming that any change over a year is due to more than technique variability.

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“…The results of this study also indicate that LVEF is not systematically influenced by rehabilitation exercise. Changes in exercise LVEF are dramatic after MRS and tend to be exaggerated immediately after surgery so that LVEF responses measured 8 weeks after surgery may be more valid. The mechanism of the enhanced work capacity resulting from rehabilitation remains unclear.…”

Section: Discussionmentioning

confidence: 99%

Work capacity and left ventricular function during rehabilitation after myocardial revascularization surgery.

Foster¹,

Pollock²,

Anholm³

et al. 1984

Circulation

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A prospective randomized trial was conducted to evaluate the effects of exercise-based cardiac rehabilitation after myocardial revascularization surgery (MRS) on work capacity (measured in mets) and left ventricular function as determined from ejection fraction (LVEF). Twenty-eight patients undergoing MRS were randomly assigned to experimental (aerobic exercise, n = 19) or control (muscle relaxation and low-level exercise, n = 9) groups. Patients were studied before surgery (T1) and 2 (T2), 8 (T3), and 24 (T4) weeks after surgery with first-pass radionuclide angiography both while they were at rest and during maximal upright cycle ergometric exercise. Subsets of patients were also studied at T2, T3, and T4 at a standard workload of 75 W, and during maximal exercise 1 year after surgery (T5). Work capacity improved in both groups although significantly more so in the experimental group (3.9, 3.8, 6.0, and 7.3 mets and 3.7, 3.7, 4.9, and 5.7 mets at TI, T2, T3, and T4 in the experimental and control groups, respectively). The differences between groups were significant by T3. Peak exercise LVEF increased significantly in both groups from T1 to T2 then decreased at T3 and remained unchanged through T5. Peak exercise LVEF at T3 to T5 remained significantly above that observed at T 1. LVEF responses were not related to the exercise program. During a standard workload, heart rate decreased, blood pressure increased, and LVEF did not change in either group. After conclusion of the formal protocol (T4), work capacity and LVEF did not change for either group throughout an additional 6 months (T5). We conclude that exercise training significantly enhances both the magnitude and rate of the increase in work capacity after MRS, but that peak exercise LVEF is not influenced by the exercise program. Circulation 69, No. 4, 748-755, 1984. THE GROWTH of rehabilitation programs for patients with cardiovascular disease has been impressive during the 25 years since Hellerstein and Ford first presented "an orderly plan for the rehabilitation of the patient with heart disease. "' Exercise-based rehabilitation programs have a demonstrated beneficial effect on clinical status, as evidenced by improved work capacity,2' 3reduction in incidence of attacks of angina pectoris,4 and indications of a reduction in rates of morbidity/mortality.5 6 Their effect on left ventricular function, which is an important prognosticator of sur-

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Effects of exercise training on left ventricular performance and myocardial perfusion in patients with coronary artery disease

Cited by 94 publications

References 25 publications

The effects of daily exercise on susceptibility to sudden cardiac death.

The effects of daily exercise on susceptibility to sudden cardiac death.

Individual Variability of Radionuclide Ventriculography in Stable Coronary Artery Disease Patients over One Year

Work capacity and left ventricular function during rehabilitation after myocardial revascularization surgery.

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