Biomedical subjects

Ulf Ekelund

Publications and source records attributed to Ulf Ekelund.

At least 19 recordsLinked to original sources

PubMed2006

[Physical activity and clustering of CVD risk factors--secondary publication].

This study aimed to derive guidelines on physical activity. We did a cross-sectional study of 1732 9-year-old and 15-year-old children. Objectively measured physical activity was associated to clustered CVD risk with an OR for the least active of 3.29 compared with the most active quintile. The time spent in moderate activity in children where risk was elevated was less than 116 min per day in 9-year-old and less than 88 min per day in 15-year-old children. Physical activity levels should be higher than the current international guidelines of at least 1 h per day to prevent clustering of CVD risk factors.

English Abstract↗

PubMed2006

Association of weight gain in infancy and early childhood with metabolic risk in young adults.

CONTEXT: Early postnatal life has been suggested as an important window during which risks for long-term health may be influenced. OBJECTIVE: The aim of this study was to examine the independent associations between weight gain during infancy (0-6 months) and early childhood (3-6 yr) with components of the metabolic syndrome in young adults. DESIGN: This was a prospective cohort study (The Stockholm Weight Development Study). SETTING: The study was conducted in a general community. PARTICIPANTS: Subjects included 128 (54 males) singletons, followed from birth to 17 yr. MAIN OUTCOME MEASURE: None of these young adults met the full criteria for the metabolic syndrome. We therefore calculated a continuous clustered metabolic risk score by averaging the standardized values of the following components: waist circumference, blood pressure, fasting triglycerides, high-density lipoprotein cholesterol, glucose, and insulin level. RESULTS: Clustered metabolic risk at age 17 yr was predicted by weight gain during infancy (standardized beta = 0.16; P < 0.0001) but not during early childhood (standardized beta = 0.10; P = 0.23), adjusted for birth weight, gestational age, current height, maternal fat mass, and socioeconomic status at age 17 yr. Further adjustment for current fat mass and weight gain during childhood did not alter the significant association between infancy weight gain with the metabolic risk score (standardized beta = 0.20; P = 0.007). CONCLUSIONS: Rapid weight gain during infancy (0-6 months) but not during early childhood (3-6 yr) predicted clustered metabolic risk at age 17 yr. Early interventions to moderate rapid weight gain even at very young ages may help to reduce adult cardiovascular disease risks.

Adolescent↗

PubMed2006

Comparison between neural networks and multiple logistic regression to predict acute coronary syndrome in the emergency room.

OBJECTIVE: Patients with suspicion of acute coronary syndrome (ACS) are difficult to diagnose and they represent a very heterogeneous group. Some require immediate treatment while others, with only minor disorders, may be sent home. Detecting ACS patients using a machine learning approach would be advantageous in many situations. METHODS AND MATERIALS: Artificial neural network (ANN) ensembles and logistic regression models were trained on data from 634 patients presenting an emergency department with chest pain. Only data immediately available at patient presentation were used, including electrocardiogram (ECG) data. The models were analyzed using receiver operating characteristics (ROC) curve analysis, calibration assessments, inter- and intra-method variations. Effective odds ratios for the ANN ensembles were compared with the odds ratios obtained from the logistic model. RESULTS: The ANN ensemble approach together with ECG data preprocessed using principal component analysis resulted in an area under the ROC curve of 80%. At the sensitivity of 95% the specificity was 41%, corresponding to a negative predictive value of 97%, given the ACS prevalence of 21%. Adding clinical data available at presentation did not improve the ANN ensemble performance. Using the area under the ROC curve and model calibration as measures of performance we found an advantage using the ANN ensemble models compared to the logistic regression models. CONCLUSION: Clinically, a prediction model of the present type, combined with the judgment of trained emergency department personnel, could be useful for the early discharge of chest pain patients in populations with a low prevalence of ACS.

Acute Disease↗

PubMed2006

Physical activity and clustered cardiovascular risk in children: a cross-sectional study (The European Youth Heart Study).

BACKGROUND: Atherosclerosis develops from early childhood; physical activity could positively affect this process. This study's aim was to assess the associations of objectively measured physical activity with clustering of cardiovascular disease risk factors in children and derive guidelines on the basis of this analysis. METHODS: We did a cross-sectional study of 1732 randomly selected 9-year-old and 15-year-old school children from Denmark, Estonia, and Portugal. Risk factors included in the composite risk factor score (mean of Z scores) were systolic blood pressure, triglyceride, total cholesterol/HDL ratio, insulin resistance, sum of four skinfolds, and aerobic fitness. Individuals with a risk score above 1 SD of the composite variable were defined as being at risk. Physical activity was assessed by accelerometry. FINDINGS: Odds ratios for having clustered risk for ascending quintiles of physical activity (counts per min; cpm) were 3.29 (95% CI 1.96-5.52), 3.13 (1.87-5.25), 2.51 (1.47-4.26), and 2.03 (1.18-3.50), respectively, compared with the most active quintile. The first to the third quintile of physical activity had a raised risk in all analyses. The mean time spent above 2000 cpm in the fourth quintile was 116 min per day in 9-year-old and 88 min per day in 15-year-old children. INTERPRETATION: Physical activity levels should be higher than the current international guidelines of at least 1 h per day of physical activity of at least moderate intensity to prevent clustering of cardiovascular disease risk factors.

Adolescent↗

PubMed2006

A simple statistical model for prediction of acute coronary syndrome in chest pain patients in the emergency department.

BACKGROUND: Several models for prediction of acute coronary syndrome (ACS) among chest pain patients in the emergency department (ED) have been presented, but many models predict only the likelihood of acute myocardial infarction, or include a large number of variables, which make them less than optimal for implementation at a busy ED. We report here a simple statistical model for ACS prediction that could be used in routine care at a busy ED. METHODS: Multivariable analysis and logistic regression were used on data from 634 ED visits for chest pain. Only data immediately available at patient presentation were used. To make ACS prediction stable and the model useful for personnel inexperienced in electrocardiogram (ECG) reading, simple ECG data suitable for computerized reading were included. RESULTS: Besides ECG, eight variables were found to be important for ACS prediction, and included in the model: age, chest discomfort at presentation, symptom duration and previous hypertension, angina pectoris, AMI, congestive heart failure or PCI/CABG. At an ACS prevalence of 21% and a set sensitivity of 95%, the negative predictive value of the model was 96%. CONCLUSION: The present prediction model, combined with the clinical judgment of ED personnel, could be useful for the early discharge of chest pain patients in populations with a low prevalence of ACS.

Acute Disease↗

PubMed2006

Direct hospital costs of chest pain patients attending the emergency department: a retrospective study.

BACKGROUND: Chest pain is one of the most common complaints in the Emergency Department (ED), but the cost of ED chest pain patients is unclear. The aim of this study was to describe the direct hospital costs for unselected chest pain patients attending the emergency department (ED). METHODS: 1,000 consecutive ED visits of patients with chest pain were retrospectively included. Costs directly following the ED visit were retrieved from the hospital economy system. RESULTS: The mean cost per patient visit was 26.8 thousand Swedish kronar (kSEK) (median 7.2 kSEK), with admission time accounting for 73% of all costs. Mean cost for patients discharged from the ED was 1.4 kSEK (median 1.3 kSEK), and for patients without ACS admitted 1 day or less 7.6 kSEK (median 6.9 kSEK). The practice in the present study to admit 67% of the patients, of whom only 31% proved to have ACS, was estimated to give a cost per additional life-year saved by hospital admission, compared to theoretical strategy of discharging all patients home, of about 350 kSEK (39 kEUR or 42 kUSD). CONCLUSION: Costs for chest pain patients are large and primarily due to admission time. The present admission practice seems to be cost-effective, but the substantial overadmission indicates that better ED diagnostics and triage could decrease costs considerably.

Journal Article↗

PubMed2006

Criterion-related validity of the last 7-day, short form of the International Physical Activity Questionnaire in Swedish adults.

OBJECTIVE: To examine the validity of the short, last 7-day, self-administered form of the International Physical Activity Questionnaire (IPAQ). DESIGN: All subjects wore an accelerometer for seven consecutive days and completed the IPAQ questionnaire on the eighth day. Criterion validity was assessed by linear regression analysis and by modified Bland-Altman analysis. Specificity and sensitivity were calculated for classifying respondents according to the physical activity guidelines of the American College of Sports Medicine/Centers for Disease Control and Prevention. SETTING: Workplaces in Uppsala, Sweden. SUBJECTS: One hundred and eighty-five (87 males) participants, aged 20 to 69 years. RESULTS: Total self-reported physical activity (PA) (MET-min day(-1)) was significantly correlated with average intensity of activity (counts min(-1)) from accelerometry (r = 0.34, P < 0.001). Gender, age, education and body mass index did not affect this relationship. Further, subcomponents of self-reported PA (time spent sitting, time in PA, time in moderate and vigorous activity (MVPA)) were significantly correlated with objectively measured PA (P < 0.05). Self-reported time in PA was significantly different from time measured by accelerometry (mean difference: -25.9 min day(-1); 95% limits of agreement: -172 to 120 min day(-1); P < 0.001). IPAQ identified 77% (specificity) of those who met the current PA guidelines of accumulating more than 30 min day(-1) in MVPA as determined by accelerometry, whereas only 45% (sensitivity) of those not meeting the guidelines were classified correctly. CONCLUSIONS: Our results indicate that the short, last 7-days version of the IPAQ has acceptable criterion validity for use in Swedish adults. However, the IPAQ instrument significantly overestimated self-reported time spent in PA. The specificity to correctly classify people achieving current PA guidelines was acceptable, whereas the sensitivity was low.

Adult↗

PubMed2006

Upward weight percentile crossing in infancy and early childhood independently predicts fat mass in young adults: the Stockholm Weight Development Study (SWEDES).

BACKGROUND: Rapid early postnatal weight gain predicts increased subsequent obesity and related disease risks. However, the exact timing of adverse rapid postnatal weight gain is unclear. OBJECTIVE: The objective was to examine the associations between rapid weight gain in infancy and in early childhood in relation to body composition at age 17 y. DESIGN: This prospective cohort study was conducted in 248 (103 males) singletons and their mothers. Height and weight were measured at birth, 6 mo, and 3 and 6 y. The rates of weight gain during infancy (0-6 mo) and early childhood (3-6 y) were calculated as changes in sex- and age-adjusted weight SD scores during these time periods. At 17 y, body composition was measured by air-displacement plethysmography. RESULTS: Increasing weight gain during infancy and early childhood were both independently associated with larger body mass index, fat mass, relative fat mass, fat-free mass, and waist circumference at 17 y (P < 0.005 for all; adjusted for sex, birth weight, gestational age, current height, maternal socioeconomic status, and maternal fat mass). Rapid weight gain in infancy, but not in early childhood, also predicted taller height at 17 y (P < 0.001). CONCLUSIONS: Rapid weight gain in both infancy and early childhood is a risk factor for adult adiposity and obesity. Rapid weight gain in infancy also predicted taller adult height. We hypothesize that rapid weight gains in infancy and early childhood are different processes and may allow separate opportunities for early intervention against obesity risk later in life.

Adipose Tissue↗

PubMed2006

Comparison of two methods of measuring physical activity in South African older adults.

The aim of this study was to assess the validity and reliability of the Yale Physical Activity Survey (YPAS) and the short version of the International Physical Activity Questionnaire (IPAQ) in older South African adults. The YPAS includes measures of weekly energy expenditure (EE) for housework, yard work, caregiving, exercise, and recreation. The IPAQ measures total time and EE during vigorous and moderate activity, walking, and sitting. The instruments were administered twice for test-retest reliability (men, n = 52, 68 +/- 5.4 years, and women, n = 70, 66 +/- 5.8 years). Data for criterion validity were obtained from accelerometers. YPAS reliability ranged from r = .44 to.80 for men and r = .59 to .99 for women (p < .0001). IPAQ reliability was lower for men (r = .29 to .76) than for women (r = .46 to .77). Criterion validity of the YPAS was .31 to .54 for men and .26 to .29 for women. The YPAS and short IPAQ had comparable results for reliability and criterion validity.

Aged↗

PubMed2006

TV viewing and physical activity are independently associated with metabolic risk in children: the European Youth Heart Study.

BACKGROUND: TV viewing has been linked to metabolic-risk factors in youth. However, it is unclear whether this association is independent of physical activity (PA) and obesity. METHODS AND FINDINGS: We did a population-based, cross-sectional study in 9- to 10-y-old and 15- to 16-y-old boys and girls from three regions in Europe (n = 1,921). We examined the independent associations between TV viewing, PA measured by accelerometry, and metabolic-risk factors (body fatness, blood pressure, fasting triglycerides, inverted high-density lipoprotein (HDL) cholesterol, glucose, and insulin levels). Clustered metabolic risk was expressed as a continuously distributed score calculated as the average of the standardized values of the six subcomponents. There was a positive association between TV viewing and adiposity (p = 0.021). However, after adjustment for PA, gender, age group, study location, sexual maturity, smoking status, birth weight, and parental socio-economic status, the association of TV viewing with clustered metabolic risk was no longer significant (p = 0.053). PA was independently and inversely associated with systolic and diastolic blood pressure, fasting glucose, insulin (all p < 0.01), and triglycerides (p = 0.02). PA was also significantly and inversely associated with the clustered risk score (p < 0.0001), independently of obesity and other confounding factors. CONCLUSIONS: TV viewing and PA may be separate entities and differently associated with adiposity and metabolic risk. The association between TV viewing and clustered metabolic risk is mediated by adiposity, whereas PA is associated with individual and clustered metabolic-risk indicators independently of obesity. Thus, preventive action against metabolic risk in children may need to target TV viewing and PA separately.

Adolescent↗

PubMed2006

Dietary fat intake predicts 1-year change in body fat in adolescent girls with type 1 diabetes.

OBJECTIVE: The purpose of this study was to determine whether objectively measured physical activity and dietary macronutrient intake differentially predict body fat in adolescent girls with type 1 diabetes and control girls. RESEARCH DESIGN AND METHODS: This study comprised 23 girls (12-19 years) with type 1 diabetes and 19 age-matched healthy control girls. At baseline, physical activity and energy intake were assessed for 7 consecutive days by accelerometry and a structured food diary, respectively. Body composition was measured by dual-energy X-ray absorptiometry at baseline and after 1 year. RESULTS: Fat intake was positively related to a 1-year change in percentage body fat (P = 0.006), after adjustment for total energy intake. No significant interaction was observed (case-control group x main exposure), indicating that the association between fat intake and gain in body fat was similar in both groups. Physical activity did not predict gain in body fat; however, total physical activity was positively associated with a gain in lean body mass (P < 0.01). Girls treated with six daily dosages of insulin increased their percentage of body fat significantly more than those treated with four daily injections (P < 0.05). CONCLUSIONS: In this prospective case-control study, we found that fat intake predicted gain in percentage of body fat in both adolescent girls with type 1 diabetes and healthy control girls. The number of daily insulin injections seems to influence the accumulation of body fat in girls with type 1 diabetes.

Absorptiometry, Photon↗

PubMed2005

Effect of combined movement and heart rate monitor placement on physical activity estimates during treadmill locomotion and free-living.

A placement effect on activity measures from movement sensors has been reported during treadmill and free-living activity. Positioning of electrodes may impact on movement artifact susceptibility as well as surface ECG waveform amplitudes and thus potentially on the precision by which heart rate (HR) is ascertained from such ECG traces. The purpose of this study was to examine the extent to which placement of the combined HR and movement sensor, Actiheart, influences measurement of HR and movement, and estimates of energy expenditure. A total of 24 participants (20-39 years, 45-109 kg, 1.54-2.05 m, 19-29 kg m(-2)) were recruited. Whilst wearing two monitors, one placed at the level of the third intercostal space (upper position) and one just below the apex of the sternum (lower position), study participants performed level walking, incline walking, and level running on treadmill, and completed at least one day of free-living monitoring. Placement differences in HR data quality, movement counts, and energy expenditure (estimated from combined HR and movement) were analyzed with regression techniques. Quality of HR data was generally higher when monitors were placed in the lower position. This effect was more pronounced in men during both treadmill activity (relative risk, RR [95% CI] of noisy HR data in upper vs. lower position, RR=1.3[0.3; 5.6] in women, RR=174[14; 2,156] in men) and during free-living (RR=1.2[0.4; 3.3] in women, RR=25[9.6; 67] in men). There were minor placement differences (< or =8%) in movement counts only in women during incline walking and running. During free-living, no placement effect on counts was observed. In all test scenarios, estimates of energy expenditure from the two positions were not significantly different. Positioning the Actiheart at the level below the sternum may yield cleaner HR data. Regardless of which position is used, this has little or no effect on movement counts and energy expenditure estimates, which is encouraging for studies where research participants may have to position the monitors themselves.

Adult↗

PubMed2005

PPARGC1A genotype (Gly482Ser) predicts exceptional endurance capacity in European men.

Animal and human data indicate a role for the peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PPARGC1A) gene product in the development of maximal oxygen uptake (V(O2 max)), a determinant of endurance capacity, diabetes, and early death. We tested the hypothesis that the frequency of the minor Ser482 allele at the PPARGC1A locus is lower in World-class Spanish male endurance athletes (cases) [n = 104; mean (SD) age: 26.8 (3.8) yr] than in unfit United Kingdom (UK) Caucasian male controls [n = 100; mean (SD) age: 49.3 (8.1) yr]. In cases and controls, the Gly482Ser genotype met Hardy-Weinberg expectations (P > 0.05 in both groups tested separately). Cases had significantly higher V(O2 max) [73.4 (5.7) vs. 29.4 ml x kg(-1) x min(-1) (3.8); P < 0.0001] and were leaner [body mass index: 20.6 (1.5) vs. 27.6 kg/m2 (3.9); P < 0.0001] than controls. In unadjusted chi2 analyses, the frequency of the minor Ser482 allele was significantly lower in cases than in controls (29.1 vs. 40.0%; P = 0.01). To assess the possibility that genetic stratification could confound these observations, we also compared Gly482Ser genotype frequencies in Spanish (n = 164) and UK Caucasian men (n = 381) who were unselected for their level of fitness. In these analyses, Ser482 allele frequencies were very similar (36.9% in Spanish vs. 37.5% in UK Caucasians, P = 0.83), suggesting that confounding by genetic stratification is unlikely to explain the association between Gly482Ser genotype and endurance capacity. In summary, our data indicate a role for the Gly482Ser genotype in determining aerobic fitness. This finding has relevance from the perspective of physical performance, but it may also be informative for the targeted prevention of diseases associated with low fitness such as Type 2 diabetes.

Adult↗

PubMed2005

Leptin predicts a worsening of the features of the metabolic syndrome independently of obesity.

OBJECTIVE: The term metabolic syndrome (MS) describes a cluster of cardiovascular risk factors including dyslipidemia, glucose intolerance, insulin resistance, and hypertension. Obesity increases the risk of MS, but as obesity is neither necessary nor sufficient to cause the syndrome, there is considerable interest in identifying obesity-independent pathways. One such pathway may involve the actions of the adipokine leptin, which is associated cross-sectionally with MS and prospectively with coronary heart disease and stroke, independently of obesity. Our goal was to test the hypothesis that leptin predicts the development of the features of MS independently of obesity. RESEARCH METHODS AND PROCEDURES: This study used a prospective population-based cohort of 748 middle-aged whites in whom baseline measures of leptin and repeated measurement of the subcomponents of the MS at 5 and 10 years were available. The features of the MS were characterized as five factors (obesity, dyslipidemia, elevated blood pressure, glucose intolerance, and insulin resistance), which were combined to create an MS summary score. RESULTS: Baseline leptin significantly predicted the development of obesity (p = 0.001) and, after adjustment for BMI, development of glucose intolerance (p = 0.016) and insulin resistance (p < 0.0001). Leptin levels did not independently predict a change in lipids or blood pressure. Leptin levels significantly predicted the development of the MS (p = 0.036), independently of baseline BMI. DISCUSSION: Leptin predicts the development of the MS independently of baseline obesity. This association is specifically related to the development of glucose intolerance and insulin resistance. The extent to which these relationships are explained through residual confounding by obesity remains to be determined.

Adult↗

PubMed2005

Physical activity and obesity prevention: a review of the current evidence.

Ecological data on temporal trends suggest that the rising prevalence of obesity is, at least in part, attributable to declining population energy expenditure. However, population-level data on trends in physical activity are scarce. In longitudinal cohort studies individuals who report higher levels of leisure-time physical activity tend to be less likely to gain weight, but studies vary in their conclusions because of issues of confounding, reverse causality and measurement error. The majority of studies suggest that low levels of activity are only weakly associated with future weight gain. Questions about dose-response can only be properly addressed by studies including objective measures of activity with known measurement error. The observational studies leave uncertainties about the direction of causality, as individuals who are overweight are less likely to stay active. Adjustment for confounding can diminish the impact of known confounders, but only randomisation can deal with issues of unmeasured confounding. Although there are a large number of clinical trials on the treatment of individuals with obesity or the prevention of weight regain among weight losers, the updated review of trials to prevent weight gain de novo only reveals six trials published since 2000 in adults and eleven in children. Not only are these trials relatively few in number but, for various methodological reasons, they are uncertain in their conclusions about whether increasing activity will be effective in preventing obesity. Whilst efforts should continue to enhance the evidence base it is wise, in the meantime, to stick to the consensus public health advice of advocating 45-60 min moderate intensity activity daily to prevent obesity.

Energy Metabolism↗

PubMed2005

Associations between physical activity and fat mass in adolescents: the Stockholm Weight Development Study.

BACKGROUND: Obesity is multifactorial. However, the accumulation of fat mass (FM) is proposed to be due to a positive energy balance, which may be caused by reduced physical activity (PA). OBJECTIVE: The objectives of the study were to describe the independent associations between PA and FM in adolescents and to describe the intergenerational association of FM between mothers and their offspring. DESIGN: We conducted a cross-sectional study in 445 (190 M, 255 F) 17-y-old adolescents and their mothers. PA was assessed with a self-reported questionnaire and validated by comparison with accelerometric data in a subsample of the cohort. Body composition was measured by using air-displacement plethysmography. RESULTS: Males were significantly more active than were females (P<0.01). PA was significantly and inversely associated with FM (beta=-3.63, P=0.005) and percentage FM (beta=-3.117, P=0.017) in males but not in females (beta=-0.576, P=0.54; beta=-0.532, P=0.59, respectively) after adjustment for birth weight and maternal FM and education level. However, FM and percentage FM in females were significantly associated with maternal FM (beta=0.159, P<0.0001; beta=0.145, P=0.002, respectively) and education level (beta=-1.048, P<0.005; beta=-1.085, P=0.006, respectively). No such associations were observed in males. CONCLUSIONS: PA was independently associated with FM in males but not in females. The data also showed an intergenerational association of FM between mothers and their daughters but not between mothers and their sons.

Adipose Tissue↗

PubMed2005

Physical activity energy expenditure predicts changes in body composition in middle-aged healthy whites: effect modification by age.

BACKGROUND: It is unclear whether physical activity energy expenditure (PAEE) predicts changes in body composition. OBJECTIVE: The objective was to describe the independent associations between PAEE and changes in body composition in a population-based cohort. DESIGN: This was a prospective population-based study conducted in 739 (311 men and 428 women) healthy middle-aged (median age: 53.8 y) whites. The median follow-up was 5.6 y. PAEE (MJ/d) was assessed by heart rate monitoring, individually calibrated by using the FLEX heart rate method. Fat mass (FM) and fat-free mass (FFM) were assessed by bioimpedance. RESULTS: Body weight (BW) at follow-up was significantly related to baseline PAEE (P < 0.05) after adjustment for sex, baseline age, FM, FFM, and follow-up time. A significant interaction between PAEE and age (P = 0.023) was observed. After the subjects were stratified (above and below the median for age), BW increased by a mean (+/-SD) of 1.7 +/- 5.9 kg (P < 0.0001) in the younger cohort. In this group, follow-up FM was significantly associated with baseline PAEE (P = 0.036) after adjustment for confounders. In the older cohort, BW did not change between baseline and follow-up. In this group, in contrast with the younger population, follow-up BW, FM, and FFM were all significantly and positively associated with baseline PAEE (P < 0.01 for all). CONCLUSIONS: Baseline PAEE predicts a change in FM in younger adults, who as a group gained weight in this study. In contrast, baseline PAEE in older adults--who were on average weight stable--is associated with a gain in BW, which was explained by an increase in FM and FFM.

Adipose Tissue↗

PubMed2005

Center of volume and total heart volume variation in healthy subjects and patients before and after coronary bypass surgery.

BACKGROUND: Total heart volume variation (THVV) and center of volume variation (COVV) likely affects the efficiency of cardiac pumping, but no study has determined COVV of the heart throughout the cardiac cycle or the effect of surgery on THVV in adults. Therefore, the purposes of this study were to determine COVV in healthy adults and patients with cardiac failure due to ischemic heart disease (IHD), identify any difference in THVV between these two groups, and determine how these parameters are affected by coronary bypass surgery. METHODS: Six healthy volunteers and eight patients before and after surgery were investigated with cardiovascular magnetic resonance imaging. The atrioventricular plane movement (AVPM), THVV and time resolved three-dimensional coordinates of the center of the cardiac volume (COVV) were measured. RESULTS: COVV followed a loop in 3D space that between the end-points was approximately 2 mm with no difference between healthy subjects and patients before surgery (P = 0.093), although AVPM was significantly lower in patients (P = 0.002). However, after surgery the COVV during the cardiac cycle doubled (P = 0.012) and the increase in THVV was significant (P = 0.050), although of very small magnitude, and the AVPM remained unchanged (P = 0.401). CONCLUSION: COVV and THVV were similar in patients and healthy subjects even though AVPM was lower in the patient population. After surgery, however, COVV doubled despite a very small change in THVV and no change in AVPM. Taken together, the results of this study may provide new insights into the energy expenditure and efficiency of cardiac pumping.

Adult↗