Vascular Function And Cardiac Autonomic Nervous Regulation Of Coronary Heart Disease Patients In Cardiac Rehabilitation At Different Times

Objective：Aim to research the change of the cardiovascular function and the modulation ofAutonomic Nervous System in patients with coronary heart disease during differentphases of cardiac rehabilitation (CR)(12weeks and12months).and to investigate therelationship between the change of the cardiovascular function and the modulation ofautonomic nervous system in patients with coronary heart disease.Methods:20patients with coronary heart disease were selected as the CHD group, and15ages matched non coronary heart disease people were recruited as a control group.Cardiovascular function, including Ankle-Brachial Index(ABI)，brachial-Ankle PulseWave Velocity (baPWV)， Augmentation Index (AI)， central Systolic BloodPressure(cSBP) were measured for both CHD group and HCG group at rest preexercise test. Then, all subjects undertook a graded exercise test on a treadmill (themodified Bruce protocol) during which time aerobic working capacity was measuredand electrocardiogram (ECG) was monitored throughout. Five minutes short-termprocess of heart rate variability (HRV) frequency domain method was applied pre-and post-exercise test to determine the subjects’ HRV at rest and recovery phases.After that, CHD patients attended a12-week supervised exercise-based cardiacrehabilitation programme, with the exercise mode, intensity, duration and frequencybeing prescribed to hiking walk,60%-80%peak Heart Rate(HRpk),50minutes ofexercise and three times per week respectively. During exercise training, heart rateand ratings of perceived exertion (RPE) were used to control exercise intensity. Thecontrol group did not participate in the exercise training. At the end of12-weektraining, all patients were re-tested for the cardiovascular function. HCG group werenot arranged to participate in the GXT due to little change being considered to occurin their cardiopulmonary function during this period. Then, CHD group continued itshome-and community-based rehabilitation. The training totally lasted for12months, during the period, we contacted the participants with telephone and went to the site toprovide help and ensure the adherence and efficacy of the exercise training. After12months CR, both CHD group and HCG group undertook the measurement ofcardiovascular function and GXT one more times.Results:1. Before12weeks CR, HCG group was higher than CHD group in their non-invasivemeasurement of cardiovascular function(ABI、baPWV、cSBP、rAI), but the differencebetween the two groups did not reach a significant level of statistics.2. After a12weeks CR, The CHD group had significant improvement in theirnon-invasive measurement of cardiovascular function(cSBP、AI、ABI) compared withvalues obtained before the training (p＜0.05), but baPWV of the group showed nosignificant change.3. After a12months home-and community-based CR, the CHD group showed nosignificant improvement in their non-invasive measurement of cardiovascularfunction except ABI, but the values still lower than those procured before12weeksCR.4. Before12weeks CR，the total power(TP), very low frequency power(VLF）, lowfrequency power(LF) and high frequency (HF) power of the CHD group were lowerthan those of HCG group, but difference did not reach the significant level. LF/HF ofthe CHD group was higher than that of HCG group but again the difference did notshow significance. After GXT, the HRV index of both groups decreased, and therewas a significant difference between the two groups in TP、VLF、LF(p＜0.05), but notin HF and LF/HF.5. After12weeks CR, there was a significant improvement in TP, VLF, LF, HF, andLF/HF, but the latter did not reach the significant level in CHD group at rest phase.After GXT, all HRV measurements showed a significant decrease(p＜0.05) exceptVLF.6. After12months home-and community-based CR, CHD group showed nosignificant improvement in HRV compared with values of before training at rest phaseexcept VLF; After GXT, CHD group showed no significant difference compared with both HCG group and itself before training.Conclusion:1After12weeks’ cardiac rehebilitation, the CHD group showed an improvement invascular function and HRV, that means delayed the progress of coronaryathrosclerosis and recovery of the impaired modulation of autonomic nervoussystem to some extent. Long-term for adherence of exercise might enable patientsto maintain the improvements obtained already in functions of both vascularsystem and autonomic nervous.2Vascular system and HRV can be used as an important indicator to evaluation theeffect of rehabilitation in patients with coronary heart disease during cardiacrehabilitation.3There is a relationship between the descendent of vascular function and thedecrement of modulation of autonomic nervous system in patients with CHD tosome extent.