Maximal Exercise Stress Test Research Articles

Abstract 2741: Paradoxical Reduction in Pulse Wave Reflection Following Maximal Exercise in Patients with Type 2 Diabetes Mellitus: Association with Exercise Central Blood Pressure

Background: Patients with type 2 diabetes mellitus (T2DM) have increased large artery stiffness and exaggerated brachial and central systolic blood pressure (SBP) responses to exercise. Elevations in exercise central SBP may be a result of increased arterial wave reflections and this study aimed to test this hypothesis. Methods: Maximal exercise stress tests were conducted in 50 T2DM patients (55 ± 8y, 70% males) and 50 controls (56 ± 8y, 70% males) matched by age, gender, maximal exercise brachial SBP and heart rate. Brachial and central BP were measured at rest and immediately post-exercise. Augmentation index (AIx), augmented pressure (AP; markers of wave reflection) and central SBP were recorded by radial tonometry. Results: Despite no significant differences between groups in maximal exercise brachial or central SBP, AIx and AP were significantly lower in T2DM patients (Table ). Exercise central SBP was inversely and independently associated with exercise AIx in the T2DM patients (β= -0.32; p=0.05) but not controls (β= -0.10; p=0.49). The presence of T2DM was also identified as a weak but significant independent determinant of exercise AIx (β= -0.19) and central SBP (β= 0.10; p<0.05 both). Conclusions: Patients with T2DM have 1) a paradoxical reduction in wave reflection at maximal exercise and 2) a significant inverse association between wave reflection and exercise central SBP that is not observed in controls. The reduced reflected pressure waves may indicate an increase in peripheral vasodilation to offset high exercise central BP. Exercise hemodynamics in T2DM patients and controls

Abnormal heart rate recovery after maximal cardiopulmonary exercise stress testing in young overweight women with polycystic ovary syndrome

Heart rate recovery (HRR) is a measure derived from exercise test, defined as the fall in heart rate during the first minute after maximal exercise. Abnormal HRR is a measure of autonomic dysfunction associated with an increased mortality. This study was performed to evaluate the HRR in polycystic ovary syndrome (PCOS). Prospective controlled clinical study. Seventy-five PCOS women compared to 75 healthy women matched for age (21.7 +/- 2.1 years vs. 21.9 +/- 1.8 years, respectively) and body mass index (BMI) (29.0 +/- 2.6 kg/m(2) vs. 29.1 +/- 2.9 kg/m(2), respectively). Subjects were studied for their hormonal and metabolic profile, and underwent cardiopulmonary exercise test (CPX). PCOS women showed a significantly reduced HRR (12.9 +/- 1.8 vs. 20.4 +/- 3.1 beats/min, P < 0.001) compared to healthy controls, an impairment in maximal oxygen consumption (18.0 +/- 2.3 ml/kg/min vs. 29.3 +/- 3.9 ml/kg/min) and in oxygen consumption at anaerobic threshold (13.6 +/- 2.6 ml/kg/min vs. 24.2 +/- 3.0 ml/kg/min). In PCOS women, abnormal HRR was inversely correlated to BMI (r = -0.582, P < 0.001) and to the area under the curve for insulin (r = -0.596, P < 0.001). Our data demonstrate an abnormal HRR after maximal CPX in young overweight PCOS patients, and that HRR should be investigated as a further potential marker of increased cardiovascular risk in PCOS.

Exercise echocardiography reveals subclinical cardiac dysfunction in young adult survivors of childhood acute lymphoblastic leukemia

Anthracyclines (AC) have contributed significantly to increased survival rate in acute lymphoblastic leukemia (ALL), although the use of these drugs is limited due to cardiotoxicity. The aim was to evaluate heart muscle function in asymptomatic adult survivors of ALL treated in early childhood in relation to the combined effects of AC and other potential cardiotoxic factors. Twenty-three young adult ALL survivors who had all received treatment with median 120 (120-400) mg AC/m(2) before the onset of puberty were examined median 21 years after remission and compared with 12 healthy controls. Basal echocardiography including two-dimensional (2D) M-mode and Doppler examination was performed, followed by a maximal exercise stress test and stress echocardiography immediately after stress test and after 5 min recovery. We found significant differences in systolic function between patients and controls at maximal exercise despite absence of reported symptoms from the patients. The most marked difference was in ejection fraction at stress 59.5% (32.6-81.1) and 77.3% (66.2-85.3), respectively (P < 0.00006). Ten out of 23 patients reduced their ejection fraction at stress compared with at rest; this was not found in any of the controls. Cardiovascular risk factors such as GH deficiency and a high proportion of trunk fat did not have an impact on cardiac function. With very long follow up in a homogenous cohort of ALL survivors, we found subclinical cardiac dysfunction with exercise stress echocardiography even after low doses of AC.

Coronary Artery Dissection Associated with Exercise Myocardial Perfusion Scintigraphy

Exercise myocardial perfusion scintigraphy (MPS) is commonly performed to assess for ischaemic heart disease. The risks of MPS are primarily related to those of an exercise stress test (EST). The overall cardiac complication rate from maximal EST is very low and is estimated at 0.8 complications per 10, 000 tests1. Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute myocardial ischaemia with fewer than 300 cases described in the literature2. We describe a male patient with acute myocardial infarction from SCAD associated with MPS.

Evaluation of Autonomic Function Underlying Slow Postexercise Heart Rate Recovery

The reduction in heart rate (HR) during the first minute of recovery immediately after a graded maximal exercise stress test (GXT) has recently been found to be a powerful and independent predictor of cardiovascular and all-cause mortality. Reduced vagal activity has been postulated as the cause, but this has not been proven in a population with slow HR recovery (HRR). To investigate autonomic contributions to HRR using time-frequency analysis in a group of individuals demonstrating slow HRR. HRR was defined as the difference in HR between peak exercise and 1 min later; a value < or = 18 bpm was set as threshold and considered abnormal. A modified continuous wavelet transform (CWT) was used to perform time-dependent spectral analysis during the baseline steady state and the following non-steady-state conditions created by GXT. This method provides dynamic measures of low-frequency (LF) and high-frequency (HF) peaks associated with autonomic activity. Individuals (N = 20) with a previous slow HRR underwent a second GXT within 3 months after their initial test. An additional eight subjects whose first GXT disclosed normal HRR were taken as a control group. Seven of 20 subjects demonstrated slow HRR (14 +/- 5 bpm) on the repeat test, and 13 subjects displayed normal HRR (29 +/- 5 bpm). Subjects with slow HRR in both GXT displayed significantly (P < 0.05) lower HF and LF fluctuations during recovery than those with normal HRR. Attenuated HRR after GXT, assessed by CWT, is indeed associated with abnormal vagal reactivation and prolonged sympathetic stimulation after termination of maximal exercise.

Peak Systolic Blood Pressure on a Graded Maximal Exercise Test and the Blood Pressure Response to an Acute Bout of Submaximal Exercise

Blood pressure (BP) is immediately reduced after aerobic exercise (postexercise hypotension [PEH]). Whether peak systolic BP on a maximal graded exercise stress test (GEST) relates to PEH is not known. This study examined associations between peak systolic BP on a GEST and PEH. Subjects were 50 men (mean +/- SEM age 43.8 +/- 1.3 years) with elevated BP (145.3 +/- 1.5/85.9 +/-1.1 mm Hg). Men completed a GEST and 3 experiments: nonexercise control and 2 cycle bouts at 40% (LIGHT) and 60% (MODERATE) of maximal oxygen consumption. After the experiments, subjects left the laboratory wearing ambulatory BP monitors. Peak systolic BP on a GEST was categorized into tertiles: low (n = 17, 197.4 +/- 2.0 mm Hg), medium (n = 16, 218.4 +/- 1.4 mm Hg), and high (n = 17, 248.9 +/- 2.8 mm Hg). Repeated-measures analysis of variance tested if BP differed over time and among experimental conditions and peak systolic BP groups. In men with high peak systolic BP, systolic BP was reduced by 7.3 +/- 2.6 mm Hg after LIGHT and by 5.0 +/- 2.2 mm Hg after MODERATE compared with nonexercise control over 10 hours, with the more apparent effects seen after LIGHT (p <0.05). In men with low peak systolic BP, systolic BP was reduced by 6.3 +/- 2.3 mm Hg after MODERATE compared with nonexercise control over 10 hours (p <0.05). In men with medium peak systolic BP, systolic BP was not different after exercise compared with nonexercise control over 10 hours (p >or=0.05). Men with high peak systolic BP had decreased systolic BP to the greatest extent after LIGHT, whereas men with low peak systolic BP reduced systolic BP after MODERATE. In conclusion, the findings of this study suggest that peak systolic BP on a GEST may be used to characterize which men with hypertension will have decreased systolic BP after acute submaximal aerobic exercise.

Chronic Fatigue Syndrome: Exercise Performance Related to Immune Dysfunction

To date, the exact cause of abnormal exercise response in chronic fatigue syndrome (CFS) remains to be revealed, but evidence addressing intracellular immune deregulation in CFS is growing. Therefore, the aim of this cross-sectional study was to examine the interactions between several intracellular immune variables and exercise performance in CFS patients. After venous blood sampling, subjects (16 CFS patients) performed a maximal exercise stress test on a bicycle ergometer with continuous monitoring of cardiorespiratory variables. The following immune variables were assessed: the ratio of 37 kDa Ribonuclease (RNase) L to the 83 kDa native RNase L (using a radiolabeled ligand/receptor assay), RNase L enzymatic activity (enzymatic assay), protein kinase R activity assay (comparison Western blot), elastase activity (enzymatic-colorimetric assay), the percent of monocytes, and nitric oxide determination (for monocytes and lymphocytes; flow cytometry, live cell assay). Forward stepwise multiple regression analysis revealed 1) that elastase activity was the only factor related to the reduction in oxygen uptake at a respiratory exchange ratio (RER) of 1.0 (regression model: R = 0.53, F (1,14) = 15.5, P < 0.002; elastase activity P < 0.002); 2) that the protein kinase R activity was the principle factor related to the reduction in workload at RER = 1.0; and 3) that elastase activity was the principle factor related to the reduction in percent of target heart rate achieved. These data provide evidence for an association between intracellular immune deregulation and exercise performance in patients with CFS. To establish a causal relationship, further study of these interactions using a prospective longitudinal design is required.

Safety And Feasibility Of Stress Testing In Patients With Implantable Cardioverter Defibrillators

Stress testing is integral to evaluate patients with heart disease. However, few data are available regarding safety of stress testing in patients with implantable cardioverter defibrillators (ICDs). Some exercise laboratories consider maximal exercise stress testing and pharmacologic stress testing with dobutamine contraindications in patients with ICDs and some laboratories inactivate ICDs prior to stress testing. PURPOSE The aim of this retrospective study was to assess the safety and feasibility of exercise and pharmacologic stress testing (PST) in patients with ICDs. METHODS Patients with ICD implantation and subsequent stress testing were included in this analysis. Chart review was performed. Primary end-points were occurrence of malignant ventricular arrhythmias (MVAs), onset of burst pacing or ICD firing, cardiopulmonary resuscitation (CPR) or death during stress testing. Secondary end-points were need for urgent coronary revascularization based on stress testing results and hospital readmissions for MVAs. RESULTS From January 1999 to December 2003, 1734 patients underwent ICD implantation or generator replacement. A total of 84 patients subsequently underwent 107 stress tests at William Beaumont Hospital, Royal Oak. Mean age was 67±12 years and 76% were men. Indications for ICD implantation were dilated cardiomyopathy (51%), sustained ventricular tachycardia (39%), sudden cardiac death (8%) and long QT syndrome (1%). 41% underwent exercise stress testing and 59% underwent PST utilizing dobutamine (21%) or dipyridamole (38%). Left ventricular ejection fraction was 32±20. 71% had fixed defects and 22% had reversible perfusion defects as determined by myocardial perfusion imaging. None of the ICDs were inactivated prior to stress testing. Heart rate at peak stress averaged 92±27 beats per minute. 83% were on beta-receptor antagonists. Although 4% of patients had self-terminating, non-sustained ventricular tachycardia at peak stress, none had sustained ventricular tachycardia precipitating burst pacing, ICD shock, CPR or death. One patient underwent urgent coronary angiography, but was found to have non-critical coronary disease. There were no hospital readmissions for MVAs. CONCLUSIONS These preliminary findings suggest that stress testing can be performed safely in patients with ICDs. MVAs requiring emergent treatment are rare occurrences during stress testing. Knowledge of programmed ventricular tachycardia and ventricular fibrillation zones may help predetermine maximal heart rates on stress testing and preclude routine inactivation of ICDs prior to testing.

Prediction of peak oxygen uptake in patients fulfilling the 1994 CDC criteria for chronic fatigue syndrome

To establish an inexpensive, simple method of predicting peak oxygen uptake (VO2peak) in patients fulfilling the 1994 Centers for Disease Control and Prevention (CDC) criteria for chronic fatigue syndrome (CFS). A retrospective observational study. An outpatient tertiary care chronic fatigue clinic. Two hundred and forty consecutive patients fulfilling the 1994 CDC criteria for CFS. Heart rate, metabolic and ventilatory parameters were measured continuously during a maximal exercise stress test on a bicycle ergometer. Using the equation peak oxygen uptake = 13.1 x peak workload +284 (used by Mullis et al., Br J Sports Med 1999; 33: 352-56), VO2peak was predicted from the peak workload of a maximal exercise capacity test. Pearson correlation coefficient and linear regression analysis were used to establish the most accurate way to predict VO2peak. Percentage error encountered when comparing actual measured VO2peak with predicted value was 17.3% (+/-10.0). A strong correlation between VO2peak and peak workload was observed (r= 0.89, p < 0.001). A regression analysis established the relation as VO2peak = 10.47 x peak workload +284.1, where VO2peak is given in ml/min and peak workload in W (error in prediction = 11.0+/-9.5%). Monitoring of the peak workload during a maximal, graded bicycle ergometric test suffices to predict the VO2peak. When predicting VO2peak the used operational definition for the diagnosis of CFS could be taken into account. Compared with the equation used by Mullis et al., peak workload is multiplied by 10.47 in order to predict peak oxygen uptake in CDC-defined CFS patients.

Kinesiophobia in chronic fatigue syndrome: Assessment and associations with disability

Nijs J, De Meirleir K, Duquet W. Kinesiophobia in chronic fatigue syndrome: assessment and association with disability. Arch Phys Med Rehabil 2004;85:1586–92. Objectives To investigate aspects of the validity of the total scores of the Tampa Scale for Kinesiophobia (TSK), Dutch Version, which was modified to make it an appropriate questionnaire for the assessment of kinesiophobia (fear of movement) in chronic fatigue syndrome (CFS) patients (the Dutch TSK-CFS), and, using this assessment tool, to examine the associations between kinesiophobia, exercise capacity, and activity limitations and participation restrictions in patients with CFS. Design Prospective observational studies. Setting An outpatient fatigue clinic. Participants In the first study, 40 patients fulfilling the 1994 US Centers for Disease Control and Prevention (CDC) criteria for CFS were enrolled. The sample of the second study consisted of 51 CDC-defined patients with CSF. Interventions Not applicable. Main outcome measures Study 1: Subjects completed a set of questionnaires; the Utrechtse Coping List (UCL), the Dutch TSK-CFS, and the Dutch Baecke Questionnaire of Habitual Physical Activity. Study 2: All patients completed 2 questionnaires (Chronic Fatigue Syndrome Activities and Participation Questionnaire [CFS-APQ], Dutch TSK-CFS) and performed a maximal exercise stress test on a bicycle ergometer. The heart rate was monitored continuously by use of an electrocardiograph. Metabolic and ventilatory parameters were measured through spirometry. Results Study 1: The Cronbach α coefficient for the individual item scores on the TSK-CFS was .80. The total scores on the Dutch TSK-CFS showed a statistically significant correlation with both the avoidance/abide subscale of the UCL (Spearman ρ=.35, P=.029) and the total score of the Baecke Questionnaire (ρ=−.45, P=.004). Study 2: The total scores on the Dutch TSK-CFS showed a statistically significant correlation with the total scores on the CFS-APQ (ρ=.39, P=.004). No statistically significant associations were observed between the exercise capacity parameters and the total scores on the Dutch TSK-CFS. Conclusions These results provide evidence for the internal consistency and the convergent and congruent validity of the scores obtained by use of the Dutch TSK-CFS. Kinesiophobia appears to be associated with activity limitations/participation restrictions but not with exercise capacity in patients with CFS.

Le Score d'activité physique de Dijon : reproductibilité et corrélations avec l'aptitude physique de sujets sains âgés

Purpose. – To validate a French physical activity score for current use in healthy elderly people. Patients and methods. – A brief questionnaire was developed for healthy elderly subjects older than 72 years. Questions asked about self-assessed physical fitness (1), daily activity (2), leisure and sport activity (5) and rest time (1). Correlations were searched between the score and several parameters of physical fitness: maximal exercise stress test (peak VO 2), six-minute walk test, 200-meter long walk test, timed up an go test. Results. – A total of 57 subjects were studied (mean age, 77.6 ±3.6 years; 28 females and 29 males). The mean time to complete the questionnaire was 3.96 minutes. Reproducibility was 0.606, as determined by Spearman's coefficient. Correlations were found between the physical activity score and peak VO 2 (0.302, P <0.05) and peak power (0.257, P <0.10). Conclusions. – This easily obtained physical activity score provides a new way to assess physical activity in active elderly subjects. The physical score correlated in part with maximal ability but must be validated in several diseases.

Effect of quinapril on the attenuated heart rate recovery of type 2 diabetic subjects without known coronary artery disease

Heart rate (HR) recovery at 1 min is a measure of the vagal reactivation that occurs after cessation of exercise. Despite ample evidence about the association of attenuated HR recovery with increased mortality, pharmacologic modification of this predictor has not been shown. On the other hand, angiotensin-converting enzyme (ACE) inhibitors are known to have vagomimetic activity. We hypothesized that ACE inhibition would increase HR recovery in a group of subjects known to have reduced HR recovery, namely diabetics. Maximal treadmill exercise stress test was performed in 31 type 2 diabetic and 31 nondiabetic male subjects with similar age, body mass index, and hypertensive status. None of the subjects had known heart disease or evidence of myocardial ischemia during the test. The diabetic subjects, after 2 weeks of treatment with quinapril, underwent a second exercise test. A third test was performed 2 to 3 weeks after cessation of quinapril treatment. At baseline, despite similar exercise capacity, the diabetics had a lower HR recovery at 1 min than nondiabetics (25 +/- 8 vs. 31 +/- 8 beats/min, p < 0.01). Quinapril significantly increased HR recovery at 1 min in diabetics (25 +/- 8 beats/min at baseline vs. 28 +/- 8 beats/min with quinapril vs. 25 +/- 7 beats/min off-therapy, p < 0.01 by analysis of variance). The attenuated HR recovery of type 2 diabetics can be improved by quinapril. Whether the improvement in HR recovery with ACE inhibition can lead to decreased mortality is currently unknown.

Chronic Fatigue Syndrome: Lack of Association Between Pain-Related Fear of Movement and Exercise Capacity and Disability

Patients who experience pain, a symptom of chronic fatigue syndrome (CFS), often exhibit kinesiophobia (irrational fear of movement). The purpose of this study was to examine whether pain-related fear of movement is associated with exercise capacity, activity limitations, or participation restrictions in patients with CFS who experience widespread pain. Sixty-four subjects met the inclusion criteria. All subjects fulfilled the 1994 Centers for Disease Control and Prevention case definition for CFS and experienced widespread myalgias or arthralgias. The subjects completed the Tampa Scale for Kinesiophobia-Dutch Version (TSK-DV) and the Dutch Chronic Fatigue Syndrome-Activities and Participation Questionnaire (CFS-APQ). They then performed a maximal exercise test on a bicycle ergometer. Heart rate was monitored continuously by use of an electrocardiograph. Ventilatory factors were measured through spirometry. Correlations between the TSK-DV scores and both the exercise capacity data and the CFS-APQ scores were assessed using the Spearman rank correlation coefficient. Using the Mann-Whitney U test, the TSK-DV scores were compared between subjects who performed a maximal exercise stress test and those who did not perform the test. Forty-seven subjects (73.4%) attained a total score of greater than 37 on the TSK-DV, indicating high fear of movement. Neither the exercise capacity data nor the CFS-APQ scores indicated a correlation with the TSK-DV scores (n=64). Subjects who did not perform a maximal exercise capacity test had more fear of movement (median TSK-DV score=43.0, interquartile range=10.3) compared with those who did perform a maximal exercise capacity test (median TSK-DV score=38.0, interquartile range=13.2; Mann-Whitney U-test score=322.5, z=-1.974, P=.048), but the correlation analysis was unable to reveal an association between exercise capacity and kinesiophobia in either subgroup. These results indicate a lack of correlation between kinesiophobia and exercise capacity, activity limitations, or participation restrictions, at least in patients with CFS who are experiencing widespread muscle or joint pain.

Role of Parasympathetic Activity in Heart Rate Recovery After Maximal Exercise in Cardiac Patients

1471 An abnormal heart rate recovery (HRR), defined as less than an 18 bpm reduction during the first minute of recovery after maximal exercise stress test (GXT), has recently been found to be a powerful, independent predictor of cardiovascular (CV) mortality. It has been suggested, yet not proven that an abnormal HRR is associated with reduced parasympathetic activity. PURPOSE: To investigate parasympathetic activity during recovery from GXT in cardiac patients and in subjects with CV risk factors. METHODS: 18 patients with an abnormal HRR from a prior GXT (in the previous 3–9 months) underwent a second GXT using the Bruce Protocol on a treadmill. 12-lead ECG and respiration were acquired continuously at 500 Hz during: 10 min rest, GXT and 10 min of recovery. A modified Continuous Wavelet (CWT) transform designed in our lab was used to perform time-dependent spectral analysis during the non steady state conditions created by GXT. We focus on the instantaneous fluctuations in HR in two regions of power: a high frequency (HF) peak, located around the respiratory frequency (0.18–0.7 Hz during exercise) and a low frequency (LF) peak centered around 0.1 Hz. HF peak reflects primarily vagal activity while LF fluctuations are an estimate of combined vagal and β sympathetic activity to the heart. Comparisons were made using two-way repeated measures ANOVA and ttests. RESULTS: Thirteen of the 18 patients displayed normal HRR upon the repeat GXT. Patients with abnormal HRR (n = 5, 12.5 ± 4.4 bpm reduction vs. 28.8 ± 8.5 bpm, p<0.001) had higher resting HR (97 ± 19 bpm vs. 73 ± 9 bpm, p<0.001) and reached similar peak exercise HR (145 ± 15 bpm vs. 142 ± 17 bpm, p = NS), compared to patients with normal HRR. Time-dependent frequency decomposition (by CWT) shows that patients with abnormal HRR displayed significantly lower HF fluctuations (p<0.05) at one-min post exercise, than did those with normal HRR. CONCLUSIONS: Investigation of autonomic function by Heart Rate Variability analysis reveals that abnormal HRR after GXT is indeed associated with reduced vagal function, and patients with abnormal HRR may have chronic autonomic dysfunction. It is important to note the high prevalence of patients with previous abnormal HRR after GXT, who demonstrate a “normal” HRR upon a second GXT.

Disability evaluation in chronic fatigue syndrome: associations between exercise capacity and activity limitations/participation restrictions.

In an attempt to examine whether impairments in cardiorespiratory fitness are associated with daily functioning in patients with chronic fatigue syndrome (CFS), this study addresses the correlations between exercise capacity and activity limitations/participation restrictions. Prospective observational study. An outpatient tertiary care, chronic fatigue clinic at the Vrije Universiteit Brussel (VUB), Belgium. Seventy-seven patients fulfilling the 1994 Centers for Disease Control and Prevention (CDC) case definition for CFS. All patients filled in the Chronic Fatigue Syndrome Activities and Participation Questionnaire (CFS-APQ) and performed a maximal exercise stress test on a bicycle ergometer. Heart rate was monitored continuously by use of an electrocardiograph. Metabolic and ventilatory parameters were measured through spirometry. A statistically significant correlation between the score obtained with the CFS-APQ and the body weight-adjusted peak oxygen uptake (Spearman rho = -0.32; p = 0.005), functional aerobic impairment (rho = 0.33; p = 0.004), workload/body weight (rho = -0.30; p = 0.009), exercise duration (rho = -0.30; p = 0.008), and the percentage of target heart rate achieved (rho = -0.33; p = 0.004) was observed. The correlations between the remaining exercise capacity parameters and the scores obtained with the CFS-APQ all indicated a trend towards association (0.01 <p<0.05). These results suggest a moderate association between exercise capacity and activity limitations/participation restrictions in patients with CFS. The observed correlations lack strength to predict activity limitations/ participation restriction based on exercise capacity parameters. Disability evaluation in CFS should therefore encompass both exercise capacity testing and measurements at the activity/participation dimension.

Association between left ventricular structure and cardiac performance during effort in two morphological forms of athlete’s heart

Aim: The aim of the study was to evaluate in 263 competitive athletes possible correlations between changes induced by different sport activities in left ventricular (LV) structure and cardiac response during maximal physical effort. Methods: A total of 160 top-level endurance athletes (ATE; swimmers, runners; 28±4 years; 98 male) and 103 strength-trained athletes (ATS; weight-lifters, body-builders; 27±5 years; male), selected on the basis of training protocol (dynamic vs. static exercise), underwent standard Doppler echocardiography, heart rate variability analysis and maximal exercise stress test by bicycle ergometry. M- and B-mode echocardiographic LV measurements were determined at rest, while the following functional indexes were assessed during effort: maximal heart rate (HR), maximal systolic blood pressure (SBP) and maximal workload (Watts reached by bicycle test). Results: The two groups were comparable for age and sex, but ATS at rest showed higher HR, SBP, and body surface area (BSA). By echo analysis, LV mass index and ejection fraction did not significantly differ between the two groups. However, ATS showed increased sum of wall thickness (septum+posterior wall), relative wall thickness and LV end-systolic stress, while LV stroke volume and LV end-diastolic diameter ( P<0.01) were greater in ATE. HR variability analysis underlined in ATE increased indexes of vagal tone ( P<0.01). During maximal physical effort, ATE showed a better functional capacity, with greater maximal workload ( P<0.001) reached with lower maximal HR and SBP. After adjusting for HR, age, sex, BSA and SBP, distinct multiple linear regression models evidenced in ATE independent associations of maximal effort workload with LV end-diastolic diameter ( P<0.001), HR ( P<0.001) at rest and LV end-systolic stress ( P<0.01) were found in ATE. On the other hand, independent direct correlation of SBP max during effort with sum of wall thickness ( P<0.001), BSA ( P<0.05) and LV end-systolic stress ( P<0.001) was evidenced in ATS. Conclusions: LV structural changes in competitive athletes represent adaptation to hemodynamic overload induced by training and are consistent with different kinds of sport activity. Work capacity during exercise is positively influenced by preload increase in ATE, while increased afterload due to isometric training in ATS determines higher systemic resistance during physical effort.

Improving coronary heart disease risk assessment in asymptomatic people: role of traditional risk factors and noninvasive cardiovascular tests.

At least 25% of coronary patients have sudden death or nonfatal myocardial infarction without prior symptoms.1 Therefore, the search for coronary patients with subclinical disease who could potentially benefit from intensive primary prevention efforts is critically important. The American Heart Association’s (AHA) Prevention V Conference, “Beyond Secondary Prevention: Identifying the High Risk Patient for Primary Prevention,” addressed ways to identify more patients who are asymptomatic and clinically free of coronary heart disease (CHD) but at sufficiently high risk for a future coronary event to justify more intensive risk reduction efforts.2 In this report, we amplify on key findings and recommendations of the AHA Prevention V conference, highlight new research since the conference, and propose an approach to the use of office-based testing and additional noninvasive procedures in selected patients to better define their coronary event risk. The recommendations are concordant with the recently released approach to risk assessment and management from the third report of the Adult Treatment Panel of the National Cholesterol Education Program (ATP-III).3 Enthusiasm for primary prevention and risk assessment in asymptomatic people has been spurred by recent advances in prevention research. Lipid-lowering trials demonstrated that primary prevention of coronary events is feasible, evidenced by the West of Scotland Coronary Primary Prevention Study (WOSCOPS) trial4 of hypercholesterolemic men and by the Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS) trial5 in average or typical risk men and women with only moderate lipid abnormalities. Aspirin6 or ACE inhibitors7 can also reduce risk in selected asymptomatic, high-risk people. Emerging coronary risk factors have been described including inflammatory, infectious, and thrombotic markers,8 and there has been a steady flow of reports that focus attention on potential new ways of predicting coronary risk.9 In addition, noninvasive tests for subclinical atherosclerotic disease are available …

EFFECT OF SMOKING CESSATION ON EXERCISE PERFOR-MANCE IN FEMALE ISCHEMIC AND NON ISCHEMIC SMOKERS PARTICIPATING IN EXERCISE TRAINING

Poster #10 We evaluated in a randomized prospective trial the possible effect of smoking cessation on exercise performance in middle aged female ischemic and non ischemic smokers who underwent vigorous exercise training as an adjunt to a cognitive-behavioral smoking cessation treatment program. A total of 252 patients met the criteria for this sub study; of these 124 were in the contact control group (non exercising; 62 with ischemic heart disease [IHD] and 62 without IHD) and 128 were in the exercise training group (64 with IHD and 64 without IHD). All groups had a graded maximal exercise stress test performed on a treadmill before and after 26 weeks of treatment. All subjects participated in a 26 session, group-based, cognitive-behavioral treatment program for nicotine dependence. Subjects in the contact condition participated in a 2 supervised health education lectures per week but did no engage in regular exercise. Subjects in the exercise groups trained 3 times a week for 13 weeks and 5 times a week later, averaging 80 to 85% of maximum heart rate achieved on their baseline exercise test. On the 26 week exercise stress test, the exercise groups did significantly better than control groups in all aspects of exercise performance. Those who quit showed a further increase in their exercise test duration (P < 0.001) and had a greater increase in calculated peak oxygen consumption, (V02) ml/kg/min. In conclusion, women with and without IHD who undergo a vigorous exercise training program and quit smoking demonstrate improved exercise performance over those who continue to smoke.

Silent ischemia during voluntary detraining and future cardiac events in master athletes.

To determine whether exercise-induced silent ischemia in older master athletes following a 3-month period of deconditioning is a predictor of future cardiovascular events. A longitudinal study of a cohort of master athletes. The Geriatric Research Education and Clinical Center (GRECC), Baltimore VA Medical Center, Baltimore, Maryland. Ten older (59 +/- 8 years, mean +/- SD), highly conditioned (maximal aerobic capacity VO2max 50 +/- 5 mL/kg/min), aerobically trained athletes. Five to eight years of longitudinal follow-up of athletes who had previously participated in a 3-month-long detraining intervention. At baseline, all 10 athletes had their history taken and underwent physical examinations, metabolic testing, electrocardiogram at rest, exercise treadmill tests, exercise thallium scintigrams, and exercise multigated acquisition scans. After 3 months of deconditioning, they had repeat maximal exercise stress tests. After 5 to 8 years of follow-up, they were re-evaluated, including history and physical examination and measurement of their VO2max. All 10 master athletes had normal studies at baseline. At the end of 3 months of detraining, three of these athletes had exercise-induced silent ischemia, which disappeared after retraining in two subjects and persisted at a higher heart rate in one subject. Over a 5- to 8-year period of observation, two of these three athletes with silent ischemia experienced major cardiac events (sudden death, cardiac bypass surgery). The other seven athletes did not have any cardiovascular events. Exercise-induced silent ischemia after a short period of detraining in highly trained older athletes may be a predictor of future cardiac events. A study with a larger cohort is warranted.

Intensive rehabilitation of emotionally distressed patients after coronary by-pass grafting.

To evaluate whether the status of emotionally distressed post coronary by-pass surgery patients can be improved by a comprehensive, in-patient rehabilitation programme. Cross-sectional. Rehabilitation hospital. One hundred and fifty-two post coronary by-pass surgery patients referred to an intensive rehabilitation programme. The study group was divided into two subgroups, according to the level of emotional distress. Forty-three (30%) out of 142 patients who completed the Nottingham Health Profile were considered to be distressed. The comprehensive 4-week inpatient rehabilitation programme consisted of daily physical exercise, lectures about coronary disease and risk factors, psychological support and nutrition counselling. Physical fitness, blood lipids and quality of life questionnaires. The two-way analysis of variance showed that emotionally distressed patients achieved equally good results as those obtained by nondistressed patients in performance regarding the maximal exercise stress test, maximum rate pressure product achieved, or the level of resting heart rate. Significant improvement in psychological well-being as assessed by a seven-point rating scale was observed in both groups. Both groups of patients were also equally successful in weight reduction and lowering of total cholesterol and triglycerides. Of all the patients who were employed at admission, twice the number of patients in the distressed group were in receipt of a permanent disability pension and half the number of patients was employed, compared to the initially nondistressed group, at 1-year follow-up. Distressed patients were very successful in improving their functional status and reducing risk factors when offered an intensive rehabilitation programme but they were much less successful in returning to work. Secondly, patients who were emotionally distressed after surgery did not differ in regard to disease status or physical capacity from nondistressed patients. They did, however, experience more angina pectoris both in daily life and when exposed to a maximal exercise stress test. Finally, the presence of emotional distress was easily detected by any measure of psychological status.