Effects of exercise rehabilitation program on heart rate recovery in patients with chronic heart failure.

BACKGROUND: Heart rate recovery (HRR1) immediately after exercise reflects parasympathetic activity, which is markedly attenuated in chronic heart failure (CHF) patients. The aim of our study was to examine both continuous and interval exercise training effects on HRR1 in these patients. DESIGN: The population study consisted of 29 stable CHF patients that participated at a rehabilitation program of 36 sessions, three times per week. Of the 29 patients, 24 completed the program. Patients were randomly assigned to interval {n=10 [100% peak work rate (WRp) for 30 s, alternating with rest for 30 s]} and to continuous training [n=14 (50%WRp)]. METHODS: All patients performed a symptom-limited cardiopulmonary exercise test on a cycle ergometer before and after the completion of the program. Measurements included peak oxygen uptake (VO2p), anaerobic threshold (AT), WRp, first degree slope of VO2 during the first minute of recovery (VO2/t-slope), chronotropic response [% chronotropic reserve (CR)=(peak HR - resting HR)x100/(220 - age - resting HR)], HRR1 (HR difference from peak exercise to one minute after). RESULTS: After the completion of the rehabilitation program there was a significant increase of WRp, VO2p, AT and VO2/t-slope (by 30%, P=0.01; 6%, P=0.01; 10%, P=0.02; and 27%, P=0.03 respectively for continuous training and by 21%, P<0.05; 8%, P=0.01; 6%, P=NS; and 48%, P=0.02 respectively for interval training). However, only patients exercised under the continuous training regime had a significant increase in HRR1 (15.0+/-9.0 to 24.0+/-12 bpm; P=0.02) and CR (57+/-19 to 72+/-21%, P=0.02), in contrast with those assigned to interval training (HRR1: 21+/-11 to 21+/-8 bpm; P=NS and CR: 57+/-18 to 59+/-21%, P=NS). CONCLUSIONS: Both continuous and interval exercise training program improves exercise capacity in CHF patients. However, continuous rather than interval exercise training improves early HRR1, a marker of parasympathetic activity, suggesting a greater contribution to the autonomic nervous system.     

Improvement in heart rate recovery after cardiac rehabilitation

PURPOSE: Exercise-based cardiac rehabilitation has been shown to reduce mortality in patients with coronary artery disease. Although the exact mechanisms by which exercise reduces mortality are unclear, one hypothesis invokes the effect of exercise on autonomic tone. Heart rate recovery (HRR) immediately after exercise is a marker of vagal tone that findings have shown to be a powerful predictor of all-cause mortality. This study aimed to evaluate the effect of exercise-based cardiac rehabilitation on HRR. METHODS: A retrospective study was performed. Patients who completed phase 2 cardiac rehabilitation and had entry and exit exercise stress tests (n = 34) were included in the study. A control sample was identified by review of the exercise stress laboratory database (n = 35). Then HRR at baseline and on follow-up were compared. RESULTS: After completion of phase 2 cardiac rehabilitation, the HRR improved from 18 +/- 7 bpm to 22 +/- 8 bpm (P <.001). Among controls, the HRR on serial testing were 21 +/- 10 bpm and 21 +/- 9 bpm (P =.649). The mean difference in HRR on follow-up testing was different between those enrolled in a cardiac rehabilitation program and those who were not (P =.002). CONCLUSION: Exercise training in a cardiac rehabilitation program results in HRR improvement. As a simple parameter for assessing autonomic tone, HRR may be used in a cardiac rehabilitation facility to identify patients with higher risk profiles, and can be useful for evaluating patient outcomes.     

Additional physical activity during cardiac rehabilitation leads to an improved heart rate recovery in male patients after coronary artery bypass grafting.

BACKGROUND: Heart rate recovery (HRR) after exercise, which is thought to be a marker of vagal activity, has been reported to improve after cardiac rehabilitation (CR) with exercise in patients with coronary heart disease. The aim of this study was to determine whether or not additional physical activity outside the CR program, would accelerate improvement of the HRR in male patients after coronary artery bypass grafting (CABG). METHODS AND RESULTS: Twenty male patients were enrolled in a supervised CR program at 2 weeks after CABG, and divided into an active group (walking >or=5,434 steps/day) or a less-active group. The time constant of HRR immediately measured after pedaling exercise was assessed at baseline and after the 2-week CR program. After completion of the CR program, the time constant of HRR improved from 439.7+/-177 s to 288.6+/-97.4 s in the active group (p<0.01), but no changes were observed in the less-active group. CONCLUSIONS: The results suggest that additional physical activity during a CR program may lead to an improved HRR in patients after CABG. Therefore, post-CABG patients should increase their level of physical activity in addition to that in the CR to improve their cardiac autonomic control.     

Association of metabolic syndrome with impaired heart rate recovery and low exercise capacity in young male adults

BACKGROUND: Impaired heart rate recovery (HRR) is a powerful predictor of overall mortality. AIM: The aim of the present study is to assess HRR in young adult males with metabolic syndrome and to compare HRR with those of obese patients who do not meet the criteria for metabolic syndrome. PATIENTS AND METHODS: Sixty-four newly diagnosed and untreated young male subjects (24 +/- 3 years) with metabolic syndrome and 40 age and sex matched obese or overweight control subjects (ages 23 +/- 3 years) were enrolled in the study. All subjects performed a symptom limited exercise stress test under the standard Bruce protocol. HRR was calculated in the first, second and third minutes of the recovery period. The relationship between metabolic syndrome and HRR was evaluated via logistic regression analysis and a P-value < 0.05 was accepted as significant. RESULTS: Body mass index (BMI) was 38.6 +/- 3.68 and 32.22 +/- 2.99 kg/m(2) in the study and control groups, respectively (P < 0.001). Total cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, systolic and diastolic blood pressures and fasting glucose levels were significantly higher in the study group. HRR in the first minute of the recovery period and mean exercise capacity were significantly lower in the study-group patients with metabolic syndrome (P < 0.001 and P = 0.012, respectively). CONCLUSION: We determined that HRR was impaired in young adult males with metabolic syndrome compared with obese ones who do not meet the criteria of metabolic syndrome. This decreased HRR may have prognostic value in the prediction of vascular events in patients with metabolic syndrome.     

Post‐exercise heart rate recovery in HIV‐positive individuals on highly active antiretroviral therapy. Early indicator of cardiovascular disease?

BACKGROUND: HIV infection and its treatment, specifically protease inhibitor (PI) therapy, have been associated with an increased risk for cardiovascular disease. Heart rate recovery (HRR) following peak exercise is predictive of future cardiovascular events and mortality in the general population. Nothing is known regarding HRR in individuals infected with HIV on highly active antiretroviral therapy (HAART). SUBJECTS AND METHODS: HIV-positive subjects on HAART that included a PI (HIV+PI, n=19), HIV-positive subjects on HAART that did not include a PI (HIV+noPI, n=19) and HIV-seronegative age, gender and body mass index (BMI) matched controls (Cntl, n=15) underwent a graded maximal exercise test on a cycle ergometer to volitional exhaustion. A continuous electrocardiogram was recorded and HRR was monitored every 30 s for 2 min post exercise. RESULTS: HRR at 1.5 and 2 min was significantly delayed in HIV-positive subjects both on and not on PI-based HAART compared with controls (P<0.01). CONCLUSION: HRR is impaired in HIV-positive individuals on HAART, whether or not the HAART includes a PI, compared with age, gender, BMI, and activity level matched HIV-seronegative controls. Abnormal HRR may reflect cardio-autonomic dysfunction and may be an independent risk factor for future cardiac events in HIV-positive individuals that receive HAART.     

Abnormal chronotropic reserve and heart rate recovery in patients with SLE: a case-control study

Abnormal heart-rate (HR) response during or after a graded exercise test has been recognized as a strong and an independent predictor of all-cause mortality in healthy and diseased subjects. The purpose of the present study was to evaluate the HR response during exercise in women with systemic lupus erythematosus (SLE). In this case-control study, 22 women with SLE (age 29.5?±?1.1 years) were compared with 20 gender-, BMI-, and age-matched healthy subjects (age 26.5?±?1.4 years). A treadmill cardiorespiratory test was performed and HR response during exercise was evaluated by the chronotropic reserve (CR). HR recovery (ΔHRR) was defined as the difference between HR at peak exercise and at both first (ΔHRR1) and second (ΔHRR2) minutes after exercising. SLE patients presented lower peak VO(2) when compared with healthy subjects (27.6?±?0.9 vs. 36.7?±?1.1?ml/kg/min, p?=?0.001, respectively). Additionally, SLE patients demonstrated lower CR (71.8?±?2.4 vs. 98.2?±?2.6%, p?=?0.001), ΔHRR1 (22.1?±?2.5 vs. 32.4?±?2.2%, p?=?0.004) and ΔHRR2 (39.1?±?2.9 vs. 50.8?±?2.5%, p?=?0.001) than their healthy peers. In conclusion, SLE patients presented abnormal HR response to exercise, characterized by chronotropic incompetence and delayed ΔHRR.     

Cardiac rehabilitation is associated with an improvement in C-reactive protein levels in both men and women with cardiovascular disease

PURPOSE: Inflammation is involved in the development of atherosclerotic plaque. The most studied indicator of inflammation in coronary heart diseases (CHD) is C-reactive protein (CRP) which has prognostic significance in those with CHD. The purpose of this study is to evaluate the effect of participation in cardiac rehabilitation (CR) on this marker of vascular inflammation, CRP. METHODS: We analyzed CRP levels in 172 patients with CHD who participated in a CR program. RESULTS: Men and women in CR demonstrated significant improvement in body mass index (-0.35, P = .002), exercise capacity (METs 1.8, P < .0001), HDL-C (1.8, P = .003), and CRP (-3.1, P = .003). The improvement in CRP was not significantly different based on age or the presence of metabolic syndrome. CONCLUSION: Participation in CR was associated with a marked improvement of cardiac risk factors and appears to independently decrease the level of CRP regardless of gender, age, or presence of metabolic syndrome.     

Decreased heart rate recovery after exercise in patients with congestive heart failure: effect of beta-blocker therapy

BACKGROUND: Decreased heart rate recovery (HRR) is a predictor of mortality in patients with coronary artery disease and preserved left ventricular function. We investigated the changes in HRR and assessed the impact of beta-blockade therapy on these parameters in patients with symptomatic congestive heart failure (CHF). METHODS AND RESULTS: HRR, defined as the difference from peak exercise heart rate (HR) to HR measured at 1, 2, and 3 minutes after maximal exercise test, was studied in 23 stable CHF patients and 12 healthy subjects. Patients with CHF performed a maximal exercise test using a Ramp protocol before and after 6 months of therapy with either metoprolol or carvedilol. Patients with CHF exhibited a significantly attenuated HRR compared with healthy subjects at 1 minute (17.8 +/- 5.8 versus 26.8 +/- 16.2 beats), 2 minutes (34.0 +/- 10.6 versus 48.0 +/- 11.2 bpm) and 3 minutes (41.0 +/- 12.4 versus 60.0 +/-12.4 bpm) after exercise (P<.05 for all parameters). Beta-blocker therapy for 6 months did not significantly improve HRR. CONCLUSION: HRR is markedly attenuated in stable CHF patients compared with healthy subjects. Long-term beta-blocker therapy appears to cause no significant improvement in HRR up to 3 minutes after maximal exercise.     

The Difference of Heart Rate Recovery between Males with and without Erectile Dysfunction

Aim: In this study, we aimed to investigate the relationship between heart rate recovery (HRR) time and Chronotropic Index (CHIND) parameters, which also reflect autonomic function, after exercise stress test (EST) in males with or without erectile dysfunction (ED), and we investigated the relationship between HRR and CHIND and serum steroid hormone levels. Material and Methods: A total of 135 participants (mean age: 45.0 ± 11.8 years) were enrolled into the study. Detailed biochemical and hormonal analyses, 12‐lead electrocardiography and EST (Treadmill) were performed in all participants. Erectile function was assessed using the International Index of Erectile Function (IIEF) questionnaire form. Patients were categorized into two groups according to their IIEF scores as ED (+) (IIEF < 26) and ED (?) (IIEF ≥ 26). Afterward, statistical analyses were performed to evaluate the correlations between ED and HRR and CHIND. Results: A total of 65 patients were ED (+) (mean age 44.9 ± 6.4 years), while 70 patients (mean age 43.7 ± 7.7 years) had normal erectile status. There were statistically significant differences in CHIND (P = 0.015) and HRR time (P = 0.037) between ED (+) and ED (?) patients. In correlation analysis, IIEF score was found positively correlated with HRR and metabolic equivalent (MET) values (r_HRR= 0.293, P = 0.037; r_METs= 0.388, P = 0.011, respectively). Linear regression analysis revealed that METs value and total exercise time had a more linear relationship with IIEF score compared to the other EST parameters (p_METs= 0.002 and p_TET= 0.015, respectively). Conclusion: Chronotropic incompetence and dynamic postexercise autonomic dysfunction are present in ED patients. This condition may reflect decreased functional capacity and exercise intolerance in these patients. Ann Noninvasive Electrocardiol 2010;15(3):223–229     

South Asian or Afro-Caribbean ethnicity is not associated with altered 1 min heart rate recovery estimates in suspected coronary artery disease patients

Heart rate recovery following a Bruce exercise protocol provides prognostic information on survival. We investigated the impact of ethnicity on HRR in 271 consecutive patients being assessed for CAD in three main ethnic groups (Caucasian (C); South Asian (SA); Afro-Caribbean (AC)). Our sample contained greater referral of younger, male South Asian subjects than would be expected on the basis of census data. The AC group had a low frequency of typical ischaemic pain. The SA sub-group, despite greater prevalence of diabetes, had marginally better HRR and a more preserved response to exercise. Multiple regression analysis revealed that age and not ethnicity was the main independent predictor of HRR (p=0.007) with all three ethnic sub-groups having a similar range of exercise time. There was no evidence of under referral of ethnic minorities. Ethnic effects in raw HRR data are most likely confounded by age.     

Effect of exercise training on heart rate recovery in patients post anterior myocardial infarction

Background

Regular exercise training has been shown to reduce mortality, improve functional capacity; and control the risk factors in myocardial infarction (MI) patients. Heart rate recovery (HRR) is a strong independent mortality predictor in patients with previous MI.

Heart rate recovery after six-minute walk test predicts pulmonary hypertension in patients with idiopathic pulmonary fibrosis

Background and objective: In patients with IPF, we sought to validate that abnormal heart rate recovery at 1 min (HRR1) after six‐minute walk test (6MWT) predicts mortality and to explore the relationship between abnormal HRR1 and pulmonary hypertension (PH). Methods: We identified IPF patients who performed a 6MWT as part of their clinical evaluation between 2006 and 2009 and were followed to lung transplantation or death. Right heart catheterization (RHC) data were collated and analysed for the subgroup who had this procedure. Results: There were 160 subjects who qualified for the survival analysis, and those with an abnormal HRR1 had worse survival than subjects with normal HRR1 (log‐rank P = 0.01). Eighty‐two subjects had a right heart catheter (RHC); among them, abnormal HRR1 was associated with RHC‐confirmed PH (χ² = 4.83, P = 0.03) and had a sensitivity, specificity, positive predictive value and negative predictive value of 52%, 74%, 41% and 82%, respectively, for PH. In bivariate and multivariable analyses, abnormal HRR1 appeared to be the strongest predictor of RHC‐confirmed PH (odds ratio (OR) = 4.0, 95% CI: 1.17–13.69, P = 0.02 in the multivariable analysis). Conclusions: This study adds to data that support the validity of abnormal HRR1 as a predictor of mortality and of RHC‐confirmed PH in IPF. Research is needed to further investigate the link between abnormal HRR1 and PH and to elucidate heart–lung interactions at work during exercise and recovery in patients with IPF.     

Effect of age on exercise-induced alterations in cognitive executive function: relationship to cerebral perfusion

Regular exercise improves the age-related decline in cerebral blood flow (CBF) and is associated with improved cognitive function; however, less is known about the direct relationship between CBF and cognitive function. We examined the influence of healthy aging on the capability of acute exercise to improve cognition, and whether exercise-induced improvements in cognition are related to CBF and cortical hemodynamics. Middle cerebral artery blood flow velocity (MCAv; Doppler) and cortical hemodynamics (NIRS) were measured in 13 young (24±5 y) and 9 older (62±3 y) participants at rest and during cycling at 30% and 70% of heart rate range (HRR). Cognitive performance was assessed using a computer-adapted Stroop task (i.e., test of executive function cognition) at rest and during exercise. Average response times on the Stroop task were slower for the older compared to younger group for both simple and difficult tasks (P<0.01). Independent of age, difficult-task response times improved during exercise (P<0.01), with the improvement greater at 70% HRR exercise (P=0.04 vs. 30% HRR). Higher MCAv was correlated with faster response times for simple and difficult tasks at rest (R(2)=0.47 and R(2)=0.47, respectively), but this relation uncoupled progressively during exercise. Exercise-induced increases in MCAv were similar and unaltered during cognitive tasks for both age groups. In contrast, prefrontal cortical hemodynamic NIRS measures [oxyhemoglobin (O(2)Hb) and total hemoglobin (tHb)] were differentially affected by exercise intensity, age and cognitive task; e.g., there were smaller increases in [O(2)Hb] and [tHb] in the older group between exercise intensities (P<0.05). These data indicate that: 1) Regardless of age, cognitive (executive) function is improved while exercising; 2) while MCAv is strongly related to cognition at rest, this relation becomes uncoupled during exercise, and 3) there is dissociation between global CBF and regional cortical oxygenation and NIRS blood volume markers during exercise and engagement of prefrontal cognition.     

Heart rate recovery after exercise is a predictor of mortality,independent of the angiographic severity of coronary disease

OBJECTIVES: We sought to determine whether abnormal heart rate recovery predicts mortality independent of the angiographic severity of coronary disease. BACKGROUND: An attenuated decrease in heart rate after exercise, or heart rate recovery (HRR), has been shown to predict mortality. There are few data on its prognostic significance once the angiographic severity of coronary artery disease (CAD) is ascertained. METHODS: For six years we followed 2,935 consecutive patients who underwent symptom-limited exercise testing for suspected CAD and then had a coronary angiogram within 90 days. The HRR was abnormal if < or =12 beats/min during the first minute after exercise, except among patients undergoing stress echocardiography, in whom the cutoff was < or =18 beats/min. Angiographic CAD was considered severe if the Duke CAD Prognostic Severity Index was > or =42 (on a scale of 0 to 100), which corresponds to a level of CAD where revascularization is associated with better long-term survival. RESULTS: Severe CAD was present in 421 patients (14%), whereas abnormal HRR was noted in 838 patients (29%). There were 336 deaths (11%). Mortality was predicted by abnormal HRR (hazard ratio [HR] 2.5, 95% confidence interval [CI] 2.0 to 3.1; p < 0.0001) and by severe CAD (HR 2.0, 95% CI 1.6 to 2.6; p < 0.0001); both variables provided additive prognostic information. After adjusting for age, gender, standard risk factors, medications, exercise capacity, and left ventricular function, abnormal HRR remained predictive of death (adjusted HR 1.6, 95% CI 1.2 to 2.0; p < 0.0001); severe CAD was also predictive (adjusted HR 1.4, 95% CI 1.1 to 1.9; p = 0.008). CONCLUSIONS: Even after taking into account the angiographic severity of CAD, left ventricular function, and exercise capacity, HRR is independently predictive of mortality.     

Heart rate recovery--a potential marker of clinical outcomes in heart failure patients receiving beta-blocker therapy

BACKGROUND: Heart rate recovery (HRR) within the first few minutes of graded exercise has been associated with impaired clinical outcomes in patients being evaluated for coronary artery disease. HRR is abnormal in patients with heart failure (HF), but has not been associated with clinical outcomes in these patients. The objective of the present study was to determine whether HRR following cardiopulmonary exercise testing (CPET) correlates with peak oxygen consumption (VO(2)), and whether it impacts clinical outcomes, including HF hospitalizations and total mortality, or the need for cardiac transplantation. METHODS: CPET was performed in 78 patients referred to the Montreal Heart Institute (Montreal, Quebec) with congestive HF between January 2000 and December 2002. All patients had New York Heart Association class II or III HF with a left ventricular ejection fraction of 45% or lower. Mean (+/- SD) age was 53+/-11 years and left ventricular ejection fraction was 27+/-9%. Forty-four per cent had ischemic cardiomyopathy, 88% received beta-blockers and 79% received angiotensin-converting enzyme inhibitors. HRR was defined as the difference from peak exercise HR to HR measured at specific time intervals. HRR was calculated 30 s, 60 s, 90 s and 120 s after exercise. RESULTS: Mean peak VO(2) was 18.0+/-5.3 mL/kg/min, resting HR was 74+/-13 beats/min and peak HR was 119+/-22 beats/min. HRR measured was 10+/-9 beats/min after 30 s, 20+/-12 beats/min after 60 s, 25+/-15 beats/min after 90 s and 30+/-13 beats/min after 120 s. At 90 s, patients with an HRR below 24 beats/min were more likely to have an HF hospitalization at five-year follow-up (eight hospitalizations [22.2%] versus two hospitalizations [2.7%]; P=0.0134). There was a correlation between peak VO(2) and HRR 90 s and 120 s after completion of the exercise test (r=0.40 after 90 s, P=0.001, and r=0.41 after 120 s, P=0.008). CONCLUSIONS: In patients with HF, blunted HRR 90 s and 120 s after CPET correlate with peak VO(2) and are associated with increased risk of worsening HF. HRR is easily measured and a useful marker for morbidity in patients with HF.     

Using exercise training to counterbalance chronotropic incompetence and delayed heart rate recovery in systemic lupus erythematosus: A randomized trial

Objective

To evaluate the efficacy of a 3‐month exercise training program in counteracting the chronotropic incompetence and delayed heart rate recovery in patients with systemic lupus erythematosus (SLE).

Methods

A 12‐week randomized trial was conducted. Twenty‐four inactive SLE patients were randomly assigned into 2 groups: trained (T; n = 15, 3‐month exercise program) and nontrained (NT; n = 13). A sex‐, body mass index–, and age‐matched healthy control (C) group (n = 8) also underwent the exercise program. Subjects were assessed at baseline and at 12 weeks after training. Main measurements included the chronotropic reserve (CR) and the heart rate (HR) recovery (ΔHRR) as defined by the difference between HR at peak exercise and at both the first (ΔHRR1) and second (ΔHRR2) minutes after the exercise test.

Results

Neither the NT SLE patients nor the C group presented any change in the CR or in ΔHRR1 and ΔHRR2 (P > 0.05). The exercise training program was effective in promoting significant increases in CR (P = 0.007, effect size [ES] 1.15) and in ΔHRR1 and ΔHRR2 (P = 0.009, ES 1.12 and P = 0.002, ES 1.11, respectively) in the SLE T group when compared with the NT group. Moreover, the HR response in SLE patients after training achieved parameters comparable to the C group, as evidenced by the analysis of variance and by the Z score analysis (P > 0.05, T versus C). Systemic Lupus Erythematosus Disease Activity Index scores remained stable throughout the study.

Conclusion

A 3‐month exercise training program was safe and capable of reducing the chronotropic incompetence and the delayed ΔHRR observed in physically inactive SLE patients.     

Blunted heart rate recovery is associated with exaggerated blood pressure response during exercise testing

Increased sympathetic activity and endothelial dysfunction are the proposed mechanisms underlying exaggerated blood pressure response to exercise (EBPR). However, data regarding heart rate behavior in patients with EBPR are lacking. We hypothesized that heart rate recovery (HRR) could be impaired in patients with EBPR. A total of 75 normotensive subjects who were referred for exercise treadmill test examination and experienced EBPR were included to this cross-sectional case–control study. The control group consisted of 75 age- and gender-matched normotensive subjects without EBPR. EBPR was defined as a peak exercise systolic blood pressure (BP) ≥210 mmHg in men and ≥190 mmHg in women. HRR was defined as the difference in HR from peak exercise to 1 min in recovery; abnormal HRR was defined as ≤12 beats/min. These parameters were compared with respect to occurrence of EBPR. Mean values of systolic and diastolic BP at baseline, peak exercise, and the first minute of the recovery were significantly higher in the subjects with EBPR. Mean HRR values were significantly lower (P < 0.001) in subjects with EBPR when compared with those without. Pearson’s correlation analysis revealed a significant positive correlation between the decrease in systolic BP during the recovery and degree of HRR in individuals without EBPR (r = 0.42, P < 0.001). Such a correlation was not observed in subjects with EBPR (r = 0.11, P = 0.34). The percentage of abnormal HRR indicating impaired parasympathetic reactivation was higher in subjects with EBPR (29 % vs 13 %, P = 0.02). In logistic regression analyses, HRR and resting systolic BP were the only determinants associated with the occurrence of EBPR (P = 0.001 and P < 0.001, respectively). Decreased HRR was observed in normotensive individuals with EBPR. In subjects with normal BP response to exercise, a linear correlation existed between the degree of HRR and decrease in systolic BP during the recovery period. However, such a correlation was not found in subjects with EBPR. Our data suggest that mechanisms underlying the blunting of the HRR might be associated with the genesis of EBPR. The association between the extent of HRR and adverse cardiovascular outcomes in patients with EBPR needs to be investigated in detail in future research.     

Influence of the Maximum Heart Rate Attained during Exercise Testing on Subsequent Heart Rate Recovery

Background: Abnormal heart rate recovery (HRR) following exercise testing has been shown to be a predictor for adverse cardiovascular events. The actual maximum heart rate (MHR) attained during the exercise test does not however have a distinct significance in traditional HRR assessment. The objective of this study was to investigate the role of MHR in HRR. Methods: This prospective study consisted of 164 patients (62% male, mean age 53.7 ± 11.7 years) who were referred for a symptom‐limited standard Bruce Protocol treadmill exercise test, based on clinical indications. The patients were seated immediately at test completion and the heart rate (HR) recorded at one and two minutes postexercise. A normal HRR was defined as a HR drop of 18 beats per minute or more at the end of the first minute of recovery. The HRR profile of patients who reached ≥85% of their maximum predicted heart rate (MPHR) during peak exercise were then compared to HRR profile of those who could not. Results: One hundred twelve patients (Group A) achieved a MHR ≥ 85% of MPHR during peak exercise whereas 52 patients (Group B) did not. Chi‐square analysis showed a higher incidence of normal HRR in Group A compared to Group B (p = 0.029). Analysis of variance with repeated measures showed that group A had a greater HRR at the first minute F_1,162= 6.98, p = <0.01) but not the second minute (F_1,162=1.83, p = .18) postexercise. Conclusion: There is a relation between the peak heart rate attained during exercise and the subsequent HRR. A low peak heart rate increases the likelihood of a less than normal HRR. Assessment of the entire heart‐rate response seems warranted for more thorough risk‐stratification. Ann Noninvasive Electrocardiol 2010;15(1):43–48     

Effects of prior exercise on postprandial lipemia: a quantitative review

The purpose of this report is to synthesize the results from studies examining the effect of exercise on postprandial lipemia to summarize the existing data and provide direction for future research. A quantitative review of the literature was performed using meta-analytic methods to quantify the effect sizes. Moderator analyses were performed to examine features of the studies that could potentially influence the effect of exercise on postprandial lipemia. Thirty-eight effects from 555 people were retrieved from 29 studies. The mean weighted effect was moderate as indicated by Cohen's d (d = -0.57; 95% confidence interval [CI], -0.71 to -0.43), indicating that people who perform exercise before meal ingestion exhibit a 0.5 standard deviation reduction in the postprandial triglyceride (TG) response relative to persons in comparison groups. There was no significant effect of study design, gender, age, type of meal ingested, exercise intensity, exercise duration, or timing of exercise on the postprandial response (P >.05). There was, however, significant variation in the effect sizes, for women for exercise performed within 24 hours of meal ingestion, and for exercise performed more than 24 hours before meal ingestion (P <.01). For studies that reported the energy expenditure of exercise, there was a significant relationship between effect size and energy expenditure (r = -.62, P =.02). Results from this quantitative review of the literature suggest that exercise has a moderate effect on the postprandial lipemic response and that the energy expenditure of prior exercise may play a role in the magnitude of this effect. Other factors that may affect the response remain to be clarified.