TABLE 3.
Heart rate variability (HRV) modification via exercise therapy among individuals with clinical conditions
| Publication | Clinical Population | n (age) | HRV assessment | Exercise therapy and duration | HRV outcome |
|---|---|---|---|---|---|
|
MI | |||||
| Sandercock et al (57) | MI, CABG, angioplasty | CR group: 38 (65.6±11.6) Control group: 23 (64.9±9) |
Short-term (5 min) supine ECG recordings at baseline and at 8 wks | 8-wk CR program: 1.5 h of aerobic exercise | Compared with the control group, the CR group had significant increases in SDNN, HF (ln), LF (ln) and R-R interval |
| Oya et al (54) | MI* | Training group: 16 (59±7) Control group: 12 (58±7) |
Short-term ECG recordings during rest, warmup and exercise at wk 1, wk 3 and mth 3 post-MI | Started wk 1 post-MI. Training group: 30 min of cycle ergometer at anaerobic threshold 2×/d for 2 wks. Control group: Walking according to CR protocol for 2 wks | HF increased in both groups. Increase was only significant in the training group from wks 1 to 3. There were no significant differences in HF when comparing the training and control groups from 3 wks to 3 mths |
| Malfatto et al (53) | MI | CR-only group: 14 (52±2) CR + BB group: 20 (53±2) BB-only group: 14 (53±3) |
Short-term ECG (15–20 min) supine at 3–4 wks post-MI, after completing 8 wks of CR and 1 yr after MI | Started 4 wks post-MI; 8 wks endurance training,1 h session of calisthenics and bicycle exercise 5 d/wk. Exercise schedule given at CR discharge | 4 wks after MI, patients taking BB had greater HRV (higher RRSD, MSSD, pNN50). 8 wks following CR, increases in MSSD and pNN50, and decreases in LF/HF were observed with greater changes observed in the BB + CR group. Effects maintained at 1 yr post-MI. BB-only group: HRV did not change over time |
| Leitch et al (59) | MI | Training group: 26 (56±1) Control group: 23 (59±1) |
24 h Holter monitoring 5–7 d post-MI and at 6 wks (after 5 d medication washout period) | Started 7–10 d post-MI. Training group: 6 wks supervised moderate-intensity hospital-based exercise training program (leg ergometry and circuit training) 30–60 min 3–4×/wk. Control group: Unsupervised low-intensity walking program (5–30 min 2×/d) | In both groups, there were significant improvements in all measures of HRV (mean R-R, SDNN, SDANN, TP, LF, HF). There were no significant differences between groups in any HRV parameter |
| Bryniarski et al (60) | MI | HTN group: 34 (52±9.4) Normotensive group: 30 (52±9.7) |
24 h ECG monitoring at baseline and following exercise program | 4-wk supervised program: 5×/wk, including gymnastics 20 min 2 ×/d; bicycle ergometer 3×/wk for 30–45 min; jogging 2×/wk for 1.5 km | CR increased all HRV indexes (SDNN, SDANN index, SDNN index, rMSSD, pNN50) in both groups. There were no differences between hypertensive or normotensive post-MI patients who had CR |
| Malfatto et al (58) | MI | Training group: 22 (52±7) Control group: 8 (53±7) |
Short-term (15 min) resting ECG recordings at 4 wks, 3 mths and 1 yr post-MI | 8 wks of endurance training: 1 h of calisthenics and stationary cycling 5×/wk. Exercise encouraged 2–3×/wk at discharge | At 3 mths post-MI, the trained pts showed significant increases in R-R, RRSD, MSSD, pNN50 and HF, as well as lower LF and LF/HF. No significant changes were observed in the untrained group. Differences were maintained at 1 yr in the trained group |
| La Rovere et al (55) | MI | Total = 22 Trained group: (47±6) Control group: (54±10) |
Short-term (15 min) ECG recordings during resting and 70º tilt, and 24 h ECG recordings at 4 and 8 wks post-MI | 4-wk in-hospital physical training program of calisthenics and bicycle ergometery at 75% to 95% of anaerobic threshold | At baseline, both groups had a predominantly LF component and a smaller HF component with no further modification after head-up tilt. After 4 wks, no resting changes were observed in HRV in either group. During head-up tilt, the trained group had significantly greater LF component increases and HF component decreases |
| Mazzuero et al (61) | Anterior MI | Training group: 22 Control group: 16 (50±8) |
24 h ECG recording during drug washout period at 4–6 wks and 6 mths post-MI | 6-mth training program. Training group: 30 min bicycle ergometry 3×/wk. Control group: Free lifestyle of choice | 24 h HRV (SDNN and LF/HF) increased from the 2nd to 8th mth postanterior MI, independently of exercise training or ejection fraction |
|
CHF | |||||
| Selig et al (67) | CHF (LVEF <40%, NYHA class II–III) | Exercise therapy group: 19 (65±13) Control group: 20 (64±9) |
Short-term (20 min supine) ECG recording | Supervised hospital 3-mth program; 3×/wk of multistation hydraulic resistance training, leg cyclic ergometers and set of 5 stairs | Exercise therapy group: After 3 mths, there were significant changes in the HRV parameters. LF and LF/HF decreased, HF increased. No changes were observed in the control group. Mean R-R, SDNN and rMSSD were not different in either group |
| Malfatto et al (65) | CHF (mean NYHA class 2.7, mean LVEF 30%) | CR group: 30 (62±7) Control: 15 (60±16) |
Short-term (10 min) ECG recordings after 10 min of supine rest and free breathing; 10 min of regular breathing at 20 acts/min; 10 min active standing | Supervised hospital-based 3-mth ambulatory rehabilitation; low-intensity training, 1 h of calisthenics, treadmill or bicycle 5×/wk. At discharge, encouraged to continue training program at home 2–3×/wk | After 3 mths of exercise: LF/HF at rest was unchanged, significant decreased LF/HF with controlled breathing and increased LF/HF during standing compared with baseline and free breathing in the rehabilitation group. Changes were greater after 6 additional mths of home-based training. No changes in control group |
| Pietila et al (66) | CHF (LVEF 36%, NYHA class II–III) | 13 (58.2±7.1) | Short-term (5 min) ECG recordings at supine rest at baseline and 6 mths | 6-mth home-based exercise program; 30 min of walking, step-board exercise, ergometer or other aerobic exercise 1×/d, 6 d/wk | Following the 6 mths of training, the HF and total R-R interval variability significantly increased |
| Kiilavuori et al (64) | CHF (LVEF <40%; NYHA class II–III) | Exercise group: 8 (52±8) Control group: 12 (52±10) |
20 h ECG recordings (12:00–08:00 h) at baseline and 3 mths | Supervised hospital-based 3-mth training program; 30 min bicycle ergometer 3×/wk | Training group: After 3 mths of exercise, HF during the day increased and 24 h HF increased. No changes in the control group. LF/HF ratio lower during the day and nonsignificant trend for lower 24 h LF/HF ratio in exercise group. Significant increase in the LF/HF ratio during the day and at night for the control group |
|
PTCA and CABG | |||||
| Tsai et al (71) | PTCA | 84 (57.0±9.3) | Short-term (5 min, supine) ECG recordings at baseline and at the end of 8 wks | Supervised outpatient and home exercise program for 8 wks (bicycle ergometer) | In the exercise group, HF power increased 10%, mean R-R interval increased 5% and there was a 5% increase in the variance in the exercise group, whereas in the control group, there were decreases in these HRV indexes |
| Lucini et al (69) | Post major IHD event (CABG, MI, PTCA) | CR group: 29 (63±1.97) Control group: 11 (53±2.38) |
Short-term (10 min supine) ECG recordings at baseline, 4 wks and following exercise program | 12 wks of 36 educational and exercise sessions. 50–60 min of stretching, calisthenics, aerobic and dynamic exercise (walking, bicycling, jogging, rowing), and hand weights. Encouraged to exercise 1–3×/wk outside of the formal program | After exercise therapy, the R-R interval variance increased significantly in the exercise group |
| Iellamo et al (68) | CABG | Training group: 45 (59.4±7.8) Untrained group: 41 (58.5±7.3) |
Short-term (10 min supine) at baseline and after 2-wk training period | Residential exercise program; 2×/d, 6×/wk for 2 wks, 30 min of stationary cycling and calisthenics | Mean R-R interval and the R-R interval significantly increased in the training group after 2 wks of exercise therapy |
| Takeyama et al (70) | CABG | Training group: 13 (60.4±7.8) Control group: 15 (61.7±8.7) |
Short-term recordings at 1 wk, 3 wks, and 3, 6 and 12 mths following surgery | All pts attended CR 1 wk after surgery. Training group: 30 min cycle ergometry 2×/d for 2 wks. Control group: Instructed to walk 200–500 m 3×/d for 2 wks | At rest, HF increased significantly from baseline at 3 mths, 6 mths and 12 mths in both groups. There was no significant difference between the groups. During constant load exercise, HF increased significantly in the training group at wk 3 and at 3 mths in the control group. The increases were smaller in the control group at all measurement points. At 3, 6 and 12 mths, the HF increases during constant load exercise were greater in the training group |
|
DM | |||||
| Figueroa et al (72) | Obese women with and without type 2 DM | With DM: 10 (50±1) Without DM: 18 (48±2) |
Short-term (5 min supine) before and after 20 min of exercise | 16 wks moderate-intensity endurance training: Supervised home-based walking program, 4 d/wk for 30–45 min | Postexercise HF and LF significantly increased in both groups by 14% after 16 wks of exercise. No differences in HRV between groups following exercise training |
| Zoppini et al (73) | Type 2 DM | 12 (65.7±5.6) | Short-term (10 min, supine and standing) ECG recordings at baseline and 6 mths | 6-mth exercise program: Moderate, aerobic exercise program for 70 min 2×/wk | Standing position: HF increased, LF decreased and LF/HF ratio decreased after exercise. There were no significant changes in HRV parameters in the supine position |
| Loimaala et al (74) | Men with type 2 DM | Exercise group: 24 (53.6±6.2) Control group: 25 (54.0±5.0) |
24 h ECG recordings | 52-wk training program: Jog or walk, and muscle strength training 2×/wk, along with conventional treatment for DM. Control group: Conventional treatment for DM only | Nonstatistically significant trend toward higher SDNN, HF and LF in the training group for the sleep values compared with the control group. HRV measures did not change between or within the study groups |
Age presented as mean (± SD) years.
*
Patients with myocardial infarction (MI) undergoing conventional therapy, angioplasty or revascularization. Refer to Table 1 for descriptions of HF, LF, pNN50, rMSSD, SDANN, SDNN and TP. BB Beta-blocker; CABG Coronary artery bypass grafting; CHF Chronic heart failure; CR Cardiac rehabilitation; d day; DM Diabetes mellitus; ECG Electrocardiogram; HTN Hypertension; IHD Ischemic heart disease; LVEF Left ventricular ejection fraction; MSSD The mean of the sum of squared differences between R-R intervals; mth Month; NYHA New York Heart Association; pts Patients; PTCA Percutaneous transluminal coronary angioplasty; RRSD The standard deviation of mean R-R interval; wk Week; yr Year