| Abstract |
Purpose: Few studies have been conducted to examine changes in lactate levels associated with the severity of
myocardial infarction during cardiac rehabilitation. Thus, this study aimed to investigate the effects of exercise-based
cardiac rehabilitation on lactate levels in patients with acute myocardial infarction. Methods: A total of eight patients
(7 males and 1 female, aged 64.1 ± 12.8 years) who were diagnosed with acute myocardial infarction and participated in
an inpatient cardiac rehabilitation program were included in this study. Lactate levels were measured using Lactate Plus
(Nova Biomedical, Rodermark, Germany), which can measure lactate levels from 0.3 to 25.0 mmol/L. Exercise intensity
during the inpatient cardiac rehabilitation period was set at 40%–60% of peak oxygen uptake (peak VO2), and
cardiopulmonary exercise testing and lactate level measurements were conducted before and after exercise. Normally
distributed data were analyzed using paired t-tests, and non-normally distributed data were analyzed using the Wilcoxon
signed-rank test. Results: VO2peak and metabolic equivalents significantly increased, and minute ventilation per unit
carbon dioxide production showed a decreasing trend but not a significant decrease (p=.014, p=.02). During the one-week
inpatient rehabilitation period, lactate levels at rest before exercise on the first and last days of rehabilitation significantly
decreased (p=.036). Lactate levels significantly increased immediately after exercise (p=.014), while lactate levels before
exercise showed a decreasing trend in all eight patients. Conclusion: In patients with acute myocardial infarction,
lactate levels increased immediately after exercise-based cardiac rehabilitation, while lactate levels at rest decreased
during the one-week rehabilitation period as aerobic capacity improved. |