RR-PO-1258

Wednesday 12:30, Palau de Congressos, Exhibition Hall  [Display No. 177]

THE ADAPTATION TO A CYCLE-ERGOMETER EXERCISE IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION UNDERGOING A PHASE I CARDIAC REHABILITATION – CARDIOVASCULAR RESPONSES AND AUTONOMIC NERVOUS ACTIVITIES DURING LOW-INTENSITY EXERCISE-. Matsunaga A*, Masuda T*, Ogura N M*, Shimizu K*, Kobayashi R*, Koda M**, Kamiya K**, Saitoh M**, Matsunaga A Y***, Kasahara Y***; *Department of Rehabilitation, School of Allied Health Sciences, Kitasato University, **Graduate School of Medical Sciences, Kitasato University. ***St Marianna University School of Medicine, Japan. PURPOSE: There are few studies to assess the adaptation process to early exercise training with treadmill or cycle-ergometer in patients with myocardial infarction (AMI). To clarify factors influencing the withdrawal from a phase I rehabilitation progress, we investigated cardiovascular responses and autonomic nervous activity to the low-intensity exercise with cycle-ergometer (10~15w, 10 min) in patients with AMI. SUBJECTS: Twenty seven male patients (mean age; 62±8) participated in this study were classified into two groups; the withdrawal (systolic blood pressure (SBP) >30mmHg during exercise, n=11) and enrolled (n=16) groups. METHODS: In addition to the clinical data, heart rate (HR) and SBP during exercise with cycle-ergometer were measured for the first three days from the beginning of the exercise. The power (ms^2) of low frequency (LF:0.05-0.2Hz) and high frequency (HF:0.2-1Hz) components were calculated by spectral analysis of HR variability, and HF and LF/HF ratio were used as indexes of parasympathetic and sympathetic nervous activities, respectively. ANALYSES: Differences of clinical characteristics between two groups were assessed for statistical significance by unpaired t test and chi-square test. The serial changes of HR, SBP, HF and LF/HF ratio in each group were analyzed by ANOVA. RESULTS: The withdrawal group showed significantly older mean age, lower left ventricular ejection fraction and longer hospital stay until the exercise as compared to the enrolled group (P<0.05, respectively). The HF decreased during the exercise and its change was significantly smaller in the withdrawal group than in the enrolled group (P<0.05). Whereas, LF/HF at the first exercise was significantly higher in the withdrawal group than in the enrolled group (P<0.05). CONCLUSION: We concluded that the factors influencing unexpected elevation of BP in a phase I rehabilitation using a cycle-ergometer were aging, deconditioning associated with cardiac dysfunction and the imbalance of autonomic nervous activities.