Effects of aerobic kinesitherapy on the heart rate variability in elderly bedridden patients

Shuihua YU

ABSTRACT

BACKGROUND:

Some researches show that aerobic kinesitherapy can strengthen the vagal tone that determines heart rate stability, increase the heart rate variability, and reduce the occurrence of cardiovascular events.

OBJECTIVE:

To observe the effect of aerobic kinesitherapy on vagal tone maintenance and the relevant indices of heart rate variability in elderly bedridden patients.

DESIGN:

A randomized controlled observation.

SETTING:

The Cadre Ward of Beijing Aerospace Central Hospital and Department of Comprehensive Internal Medicine,Yantai Convalescent Hospital of PLA.

PARTICIPANTS:

Totally 45 bedridden elderly male patients were selected from the patients admitted in the Cadre Ward of Beijing Aerospace Central Hospital and Department of Comprehensive Internal Medicine,Yantai Convalescent Hospital of PLA from February 2002 to January 2004.The patients were randomly divided into in treatment group (n =23, mean age of 69.5±8.0 years) and control group (n =22, mean age of 71.4±6.5).

INTERVENTIONS:

The therapeutic methods were similar in the two groups, I.e. Medications for amelioration of the circulation and neurotrophic treatment. On the basis of these treatments, the patients in the treatment group also had aerobic kinesitherapy through limb and trunk exercises with assistance to improve oxygen consumption of the body and increase the heart rate. In each session of exercise, the patients were supposed to attain the target heart rate of 70％ to 85％ of the personal highest safe heart rate.At the beginning, each session of exercise lasted for 10-15 minutes and the heart rate or pulse was measured every 4-6 minutes, with the patients'heart rate allowed to increase by no more than 20/minute and the patients not feeling tired. The subsequent exercise time gradually increased but not over 30-40 minutes, twice a day for no less than 5 days a week. Before and after the 20-week treatment, 24-hour dynamic electrocardiogram was examined to analyze the changes in the indices of heart rate variability. MAIN OUTCOME

MEASURES:

Before and after the 20-week treatment,the indices for heart rate variability were analyzed. The standard deviation of successive normal-to-normal R-R interval was determined for assessing the magnitude of vagus nerve activity, total power spectrum for the degree of heart rate variability, standard deviation of the mean value for the balance between the sympathetic nerve and vagus, low frequency for the dual regulation of the sympathetic nerves, root-mean-square derivations for short-term vagal function and heart rate changes, Edinburgh index for the sudden heart rate variationand the vagal activativity, high frequency for vagal regulation,and ratio of low frequency and high frequency for sympathetic nerve activity.

RESULTS:

This study involved initially 46 patients, 45 of whom completed the study and 1 patient died. After the 20-week treatment in treatment group, standard deviation of successive normal-to-normal R-R interval,standard deviation of the mean value, root mean square, Edinburgh index,high frequency and total power spectrum of heart rate variability were increased compared with those before treatment (t =12.5-38.4, P ＜ 0.01).The indices of heart rate variability was decreased in the control group 20weeks later (P ＜ 0.01).

CONCLUSION:

Aerobic kinesitherapy can improve the vagus nerve activity and the sympathetic-vagal balance, raise heart rate variability and reduce the occurrence of cardiovascular events.