Segmental myocardial viability by echocardiography at rest.

BACKGROUND: Myocardial viability assessment adds value to the therapeutic decision-making of patients with ischemic heart disease. In this feasibility study, we investigated whether established echocardiographic measurements of post-systolic shortening (PSS), strain, strain rate and wall motion score (WMS) can discover viable myocardial segments. Our hypothesis is that non-viable myocardial segments are both akinetic and without PSS. METHODS: The study population consisted of 26 examinations strictly selected by visible dysfunction. We assessed WMS, strain by speckle tracking and strain rate by tissue Doppler. The segments (16*26 = 416) were categorized into either normokinetic/hypokinetic or akinetic/dyskinetic and whether there was PSS. The reference method was the presence of scar with segmental percentage volume scar fraction >50%, detected by late gadolinium-enhanced cardiovascular magnetic resonance. Agreement with echocardiography was evaluated by Kappa coefficient. RESULTS: WMS had Kappa coefficient 0.43 (sensitivity 99%, specificity 35%). Kappa coefficient of strain was 0.28 (sensitivity 98%, specificity 23%). By combining PSS in akinetic segments with WMS and strain, the Kappa coefficient was 0.06 and 0.08 respectively. CONCLUSION: Segmental viability was best shown by the presence of systolic function. Post-systolic shortening adds no value to the assessment of segmental myocardial viability.

Effect of 5 years of exercise training on the cardiovascular risk profile of older adults: the Generation 100 randomized trial.

AIMS: The aim of this study was to compare the effects of 5 years of supervised exercise training (ExComb), and the differential effects of subgroups of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), with control on the cardiovascular risk profile in older adults. METHODS AND RESULTS: Older adults aged 70-77 years from Trondheim, Norway (n = 1567, 50% women), able to safely perform exercise training were randomized to 5 years of two weekly sessions of HIIT [∼90% of peak heart rate (HR), n = 400] or MICT (∼70% of peak HR, n = 387), together forming ExComb (n = 787), or control (instructed to follow physical activity recommendations, n = 780). The main outcome was a continuous cardiovascular risk score (CCR), individual cardiovascular risk factors, and peak oxygen uptake (VO2peak). CCR was not significantly lower [-0.19, 99% confidence interval (CI) -0.46 to 0.07] and VO2peak was not significantly higher (0.39 mL/kg/min, 99% CI -0.22 to 1.00) for ExComb vs. control. HIIT showed higher VO2peak (0.76 mL/kg/min, 99% CI 0.02-1.51), but not lower CCR (-0.32, 99% CI -0.64 to 0.01) vs. control. MICT did not show significant differences compared to control or HIIT. Individual risk factors mostly did not show significant between-group differences, with some exceptions for HIIT being better than control. There was no significant effect modification by sex. The number of cardiovascular events was similar across groups. The healthy and fit study sample, and contamination and cross-over between intervention groups, challenged the possibility of detecting between-group differences. CONCLUSIONS: Five years of supervised exercise training in older adults had little effect on cardiovascular risk profile and did not reduce cardiovascular events. REGISTRATION: ClinicalTrials.gov: NCT01666340.

Over all variability of mitral annular plane peak systolic velocity and peak global longitudinal strain rate in relation to age, body size, and sex: The HUNT Study.

BACKGROUND: Left ventricular (LV) systolic global function can be assessed by peak annular systolic velocity S'. Global longitudinal strain rate (GLSR) is relative LV shortening rate, equivalent to normalizing S' for LV length (S'n ). It has previously been shown that mitral annular plane systolic excursion (MAPSE) and global longitudinal strain (GLS) have similar biological variability, but GLS normalizes for one dimension only, inducing a systematic error, increasing body size dependence. The objective of this study was to compare S' with GLSR in the same way, comparing biological variability and body size dependence. METHODS AND RESULTS: A total of 1266 subjects from the third wave of Nord-Trøndelag Health Study (HUNT), without evidence of heart disease, were examined. Strain rate, S' and wall lengths were measured in the four walls of the two- and four-chamber views. Mean S' was 8.4 (1.4) cm/s, (S'n ) was 0.7 (0.14)s-1 and GLSR 1.02 (0.14)s-1 . All measures declined with age. Normalization of mitral annular velocities for LV length, or the use of GLSR, did not reduce overall biological variability compared with S'. S' did show a weak, positive correlation to BSA, while S'n and GLSR a slightly stronger, negative correlation to BSA. CONCLUSIONS: S', S'n , and GLSR have similar biological variability, which is mainly due to age, not body size variation. Normalizing S' for LV length (as in Sn or GLSR) reverses correlation with BSA inducing a systematic error, due to the one-dimensional normalization for one dimension only.

Left ventricular diastolic function: Effects of high-intensity exercise after acute myocardial infarction.

OBJECTIVES: Reduced left ventricular (LV) diastolic function indicates poor prognosis after acute myocardial infarction (AMI). Our aim was to study whether a twelve-week high-intensity interval training program could improve diastolic function in patients with a relatively recent AMI. DESIGN: Twenty-eight patients (mean age 56 (SD 8) years) with a recent AMI performed high-intensity interval training twice a week for 12 weeks. Each training session consisted of four 4-minute bouts at 85%-95% of peak heart rate, separated by 4-minute active breaks. A cardiopulmonary exercise test was performed to determine peak oxygen uptake (VO2peak ). Echocardiography was performed at rest and during an upright bicycle exercise test. RESULTS: There was a significant increase in mitral annulus early diastolic velocity (e') at peak exercise (75 W) from baseline to follow-up (7.9 (1.5) vs. 8.4 (1.7) cm/s, P = .012), but no change in e' at rest (7.1 (1.9) vs. 7.3 (1.7) cm/s, P = .42). There was a significant increase in VO2peak (mean (SD), 35.2 (7.3) vs. 38.9 (7.4) ml/kg/min, P < .001). e' at peak exercise correlated with VO2peak both at baseline and follow-up (r = 0.50, P = .007, and r = 0.41, P = .032). CONCLUSION: The present study shows that LV diastolic function during exercise is related to VO2peak . We also found an improvement of diastolic function after exercise training, even in a population with a relatively well preserved systolic and diastolic function. The results demonstrate the importance of obtaining measurements during exercise when evaluating the effects of exercise interventions.

Normal ranges for automatic measurements of tissue Doppler indices of mitral annular motion by echocardiography. Data from the HUNT3 Study.

BACKGROUND: Automatic quantification of left ventricular (LV) function could enhance workflow for cardiologists and assist inexperienced clinicians who perform focused cardiac ultrasound. We have developed an algorithm for automatic measurements of the mitral annular plane systolic excursion (MAPSE) and peak velocities in systole (S') and early (e') and late (a') diastole. We aimed to establish normal reference values for the automatic measurements and to compare them with manual measurements. METHODS AND RESULTS: Healthy participants (n = 1157, 52.5% women) from the HUNT3 cross-sectional population study in Norway were included. The mean age ± standard deviation (SD) was 49 ± 14 (range: 19-89) years. The algorithm measured MAPSE, S', e', and a' from apical 4-chamber color tissue Doppler imaging (cTDI) recordings. The manual measurements were obtained by two echocardiographers, who measured MAPSE by M-mode and the velocities by cTDI. For men and women, age-specific reference values were created for groups (mean ± 1.96SD) and by linear regression (mean, 95% prediction interval). Age was negatively correlated with MAPSE, S', and e' and positively correlated with a'. There were small differences between genders. Normal reference ranges were created. The coefficients of variation between automatic and manual measurements ranged from 5.5% (S') to 11.7% (MAPSE). CONCLUSION: Normal reference values for automatic measurements of LV function indices are provided. The automatic measurements were in line with the manual measurements. Implementing automatic measurements and comparison with normal ranges in ultrasound scanners can allow for quick and precise interpretation of LV function.

High-Intensity Interval Training in Patients With Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Small studies have suggested that high-intensity interval training (HIIT) is superior to moderate continuous training (MCT) in reversing cardiac remodeling and increasing aerobic capacity in patients with heart failure with reduced ejection fraction. The present multicenter trial compared 12 weeks of supervised interventions of HIIT, MCT, or a recommendation of regular exercise (RRE). METHODS: Two hundred sixty-one patients with left ventricular ejection fraction ≤35% and New York Heart Association class II to III were randomly assigned to HIIT at 90% to 95% of maximal heart rate, MCT at 60% to 70% of maximal heart rate, or RRE. Thereafter, patients were encouraged to continue exercising on their own. Clinical assessments were performed at baseline, after the intervention, and at follow-up after 52 weeks. Primary end point was a between-group comparison of change in left ventricular end-diastolic diameter from baseline to 12 weeks. RESULTS: Groups did not differ in age (median, 60 years), sex (19% women), ischemic pathogenesis (59%), or medication. Change in left ventricular end-diastolic diameter from baseline to 12 weeks was not different between HIIT and MCT (P=0.45); left ventricular end-diastolic diameter changes compared with RRE were -2.8 mm (-5.2 to -0.4 mm; P=0.02) in HIIT and -1.2 mm (-3.6 to 1.2 mm; P=0.34) in MCT. There was also no difference between HIIT and MCT in peak oxygen uptake (P=0.70), but both were superior to RRE. However, none of these changes was maintained at follow-up after 52 weeks. Serious adverse events were not statistically different during supervised intervention or at follow-up at 52 weeks (HIIT, 39%; MCT, 25%; RRE, 34%; P=0.16). Training records showed that 51% of patients exercised below prescribed target during supervised HIIT and 80% above target in MCT. CONCLUSIONS: HIIT was not superior to MCT in changing left ventricular remodeling or aerobic capacity, and its feasibility remains unresolved in patients with heart failure. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00917046.

Relation between Mitral Annular Plane Systolic Excursion and Global longitudinal strain in normal subjects: The HUNT study.

BACKGROUND: Left ventricular (LV) systolic long-axis shortening can be measured as Mitral Annular Plane Systolic Excursion (MAPSE). Global longitudinal strain (GLS) is relative LV shortening, equivalent to normalizing MAPSE for LV length (MAPSEn). The objective of this study was to test whether normalizing LV shortening reduced biological variability of MAPSE due to normalizing for heart size and, possibly BSA. Secondly to provide normal reference values for MAPSE. METHODS AND RESULTS: A total of 1266 subjects from the Nord-Trøndelag Health Study (HUNT), without evidence of heart disease were examined. MAPSE and wall lengths were measured in all three standard apical views, while GLS has been published previously. Mean MAPSE was 1.58 (0.25) cm, MAPSEn 16.3 (2.4)%, and GLS 16.7 (2.4)%. All measures declined with age, correlations between -0.50 and -0.41. MAPSE was gender independent, and less BSA dependent than MAPSEn and GLS, while relative standard deviations (SDs) were similar for all three measures. CONCLUSIONS: MAPSE, MAPSEn, and GLS have similar biological variability, which is mainly due to age variation, indicating they are equivalent in normal, and normalizing for BSA will not reduce the variability. Normalizing MAPSE for LV length (MAPSEn and GLS) normalizes for one dimension only, inducing a systematic error, which increases BSA and gender dependence. Normal age-related, gender-independent values for MAPSE are provided.

Aerobic Interval Training Reduces the Burden of Atrial Fibrillation in the Short Term: A Randomized Trial.

BACKGROUND: Exercise training is an effective treatment for important atrial fibrillation (AF) comorbidities. However, a high level of endurance exercise is associated with an increased AF prevalence. We assessed the effects of aerobic interval training (AIT) on time in AF, AF symptoms, cardiovascular health, and quality of life in AF patients. METHODS AND RESULTS: Fifty-one patients with nonpermanent AF were randomized to AIT (n=26) consisting of four 4-minute intervals at 85% to 95% of peak heart rate 3 times a week for 12 weeks or to a control group (n=25) continuing their regular exercise habits. An implanted loop recorder measured time in AF continuously from 4 weeks before to 4 weeks after the intervention period. Cardiac function, peak oxygen uptake (o2peak), lipid status, quality of life, and AF symptoms were evaluated before and after the 12-week intervention period. Mean time in AF increased from 10.4% to 14.6% in the control group and was reduced from 8.1% to 4.8% in the exercise group (P=0.001 between groups). AF symptom frequency (P=0.006) and AF symptom severity (P=0.009) were reduced after AIT. AIT improved o2peak, left atrial and ventricular ejection fraction, quality-of-life measures of general health and vitality, and lipid values compared with the control group. There was a trend toward fewer cardioversions and hospital admissions after AIT. CONCLUSIONS: AIT for 12 weeks reduces the time in AF in patients with nonpermanent AF. This is followed by a significant improvement in AF symptoms, o2peak, left atrial and ventricular function, lipid levels, and QoL. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01325675.

Exercise training and high-sensitivity cardiac troponin-I in patients with heart failure with reduced ejection fraction.

AIMS: The aims of this sub-study of the SMARTEX trial were (1) to evaluate the effects of a 12-week exercise training programme on serum levels of high sensitivity cardiac troponin I (hs-cTnI) in patients with moderate chronic heart failure (CHF), in New York Heart Association class II-III with reduced ejection fraction (HFrEF) and (2) to explore the associations with left ventricular remodelling, functional capacity and filling pressures measured with N-terminal pro brain natriuretic peptide (NT-proBNP). METHODS AND RESULTS: In this sub-study, 196 patients were randomly assigned to high intensity interval training (HIIT, n = 70), moderate continuous training (MCT, n = 59) or recommendation of regular exercise (RRE), (n = 67) for 12 weeks. To reveal potential difference between structured intervention and control, HIIT and MCT groups were merged and named supervised exercise training (SET) group. The RRE group constituted the control group (CG). To avoid contributing factors to myocardial injury, we also evaluated changes in patients without additional co-morbidities (atrial fibrillation, hypertension, diabetes mellitus, and chronic obstructive pulmonary disease). The relationship between hs-cTnI and left ventricular end-diastolic diameter (LVEDD), VO2peak, and NT-proBNP was analysed by linear mixed models. At 12 weeks, Hs-cTnI levels were modestly but significantly reduced in the SET group from median 11.9 ng/L (interquartile ratio, IQR 7.1-21.8) to 11.5 ng/L (IQR 7.0-20.7), P = 0.030. There was no between-group difference (SET vs. CG, P = 0.116). There was a numerical but not significant reduction in hs-cTnI for the whole population (P = 0.067) after 12 weeks. For the sub-group of patients without additional co-morbidities, there was a significant between-group difference: SET group (delta -1.2 ng/L, IQR -2.7 to 0.1) versus CG (delta -0.1 ng/L, IQR -0.4 to 0.7), P = 0.007. In the SET group, hs-cTnI changed from 10.9 ng/L (IQR 6.0-22.7) to 9.2 ng/L (IQR 5.2-20.5) (P = 0.002), whereas there was no change in the CG (6.4 to 5.8 ng/L, P = 0.64). Changes in hs-cTnI (all patients) were significantly associated with changes in; LVEDD, VO2peak, and NT-proBNP, respectively. CONCLUSIONS: In patients with stable HFrEF, 12 weeks of structured exercise intervention was associated with a modest, but significant reduction of hs-cTnI. There was no significant difference between intervention group and control group. In the sub-group of patients without additional co-morbidities, this difference was highly significant. The alterations in hs-cTnI were associated with reduction of LVEDD and natriuretic peptide concentrations as well as improved functional capacity.

Three-dimensional echocardiography in the evaluation of global and regional function in patients with recent myocardial infarction: a comparison with magnetic resonance imaging.

We aimed to compare three-dimensional (3D) and two-dimensional (2D) echocardiography in the evaluation of patients with recent myocardial infarction (MI), using late-enhancement magnetic resonance imaging (LE-MRI) as a reference method. Echocardiography and LE-MRI were performed approximately 1 month after first-time MI in 58 patients. Echocardiography was also performed on 35 healthy controls. Left ventricular (LV) ejection fraction by 3D echocardiography (3D-LVEF), 3D wall-motion score (WMS), 2D-WMS, 3D speckle tracking-based longitudinal, circumferential, transmural and area strain, and 2D speckle tracking-based longitudinal strain (LS) were measured. The global correlations to infarct size by LE-MRI were significantly higher (P < 0.03) for 3D-WMS and 2D-WMS compared with 3D-LVEF and the 4 different measurements of 3D strain, and 2D global longitudinal strain (GLS) was more closely correlated to LE-MRI than 3D GLS (P < 0.03). The segmental correlations to infarct size by LE-MRI were also significantly higher (P < 0.04) for 3D-WMS, 2D-WMS, and 2D LS compared with the other indices. Three-dimensional WMS showed a sensitivity of 76% and a specificity of 72% for identification of LV infarct size >12%, and a sensitivity of 73% and a specificity of 95% for identification of segments with transmural infarct extension. Three-dimensional WMS and 2D gray-scale echocardiography showed the strongest correlations to LE-MRI. The tested 3D strain method suffers from low temporal and spatial resolution in 3D acquisitions and added diagnostic value could not be proven.

Regional motion of the AV-plane is related to the cardiac anatomy and deformation of the AV-plane. Data from the HUNT study.

The study examines global and regional systolic shortening of the left (LV) and right ventricle (RV) in 1266 individuals without evidence of heart disease in the third wave of the HUNT study. Regional mitral annular systolic displacement (mitral annular plane systolic excursion [MAPSE]) was 1.5 cm in the septum and anterior walls, 1.6 cm in the lateral wall and 1.7 cm in the inferior wall, global mean 1.6 cm. Peak systolic velocity S' was 8.0, 8.3, 8.8 and 8.6 cm/s in the same walls (global mean 8.7 cm/s). All measures of LV longitudinal shortening correlated, mean MAPSE and S' also correlated with stroke volume (SV) and ejection fraction (EF). Global longitudinal strain by either method correlated with MAPSE, S' and EF, but not with SV, reflecting a systematic difference. S' and MAPSE correlated with early annular diastolic velocity (e'), reflecting that e' is the recoil from systole. Mean displacement was 2.8 (0.5) cm in the tricuspid annulus (tricuspid annular plane systolic excursion [TAPSE]). Normal values by age and sex are provided. Both TAPSE and S' were lower in women, where body size explained the sex difference. Normalisation of MAPSE and S' for wall length reduced intra-individual variation of displacement and velocity by 80%-90%, showing regional MAPSE to be related to LV wall length, and that longitudinal wall strain was relatively uniform. Displacement and S' were lowest in the septum and highest in the left and right free walls, shows systolic bending of the AV-plane into a U-shape, relating to the total cardiac volume changes during the heart cycle.

Automated tissue Doppler imaging for identification of occluded coronary artery in patients with suspected non-ST-elevation myocardial infarction.

PURPOSE: Identification of regional dysfunction is important for early risk stratification in patients with suspected non-ST-elevation myocardial infarction (NSTEMI). Strain echocardiography enables quantification of segmental myocardial deformation. However, the clinical use is hampered by time-consuming manual measurements. We aimed to evaluate whether an in-house developed software for automated analysis of segmental myocardial deformation based on tissue Doppler imaging (TDI) could predict coronary occlusion in patients with suspected NSTEMI. METHODS: Eighty-four patients with suspected NSTEMI were included in the analysis. Echocardiography was performed at admission. Strain, strain rate and post-systolic shortening index (PSI) were analyzed by the automated TDI-based tool and the ability to predict coronary occlusion was assessed. For comparison, strain measurements were performed both by manual TDI-based analyses and by semi-automatic speckle tracking echocardiography (STE). All patients underwent coronary angiography. RESULTS: Seventeen patients had an acute coronary occlusion. Global strain and PSI by STE were able to differentiate occluded from non-occluded culprit lesions (respectively - 15.0% vs. -17.1%, and 8.1% vs. 5.1%, both p-values < 0.05) and identify patients with an acute coronary occlusion (AUC 0.66 for both strain and PSI). Measurements of strain, strain rate and PSI based on TDI were not significantly different between occluded and non-occluded territories. CONCLUSION: Automated measurements of myocardial deformation based on TDI were not able to identify acute coronary occlusion in patients with suspected NSTEMI. However, this study confirms the potential of strain by STE for early risk stratification in patients with chest pain.

Retrospective Ultrasound Doppler Quantification Using a Single Acquisition in Healthy Adults.

OBJECTIVE: Using an experimental tool for retrospective ultrasound Doppler quantification-with high temporal resolution and large spatial coverage-simultaneous flow and tissue measurements were obtained. We compared and validated these experimental values against conventional measurements to determine if the experimental acquisition produced trustworthy tissue and flow velocities. METHODS: We included 21 healthy volunteers. The only exclusion criterion was the presence of an irregular heartbeat. Two ultrasound examinations were performed for each participant, one using conventional and one using experimental acquisition. The experimental acquisition used multiple plane wave emissions combined with electrocardiography stitching to obtain continuous data with over 3500 frames per second. With two recordings covering a biplane apical view of the left ventricle, we retrospectively extracted selected flow and tissue velocities. RESULTS: Flow and tissue velocities were compared between the two acquisitions. Statistical testing showed a small but significant difference. We also exemplified the possibility of extracting spectral tissue Doppler from different sample volumes in the myocardium within the imaging sector, showing a decrease in the velocities from the base to the apex. CONCLUSION: This study demonstrates the feasibility of simultaneous, retrospective spectral and color Doppler of both tissue and flow from an experimental acquisition covering a full sector width. The measurements were significantly different between the two acquisitions but were still comparable, as the biases were small compared to clinical practice, and the two acquisitions were not done simultaneously. The experimental acquisition also enabled the study of deformation by simultaneous spectral velocity traces from all regions of the image sector.

Maternal left ventricular and endothelial functions in preeclampsia.

OBJECTIVE: To compare maternal left ventricular and endothelial functions in preeclampsia and normal pregnancy, during pregnancy and after delivery. DESIGN: Observational study with follow-up. SETTING: University hospital and midwife-led antenatal care center. SAMPLES: Twenty untreated women with preeclampsia and 20 women with normal pregnancy, matched for gestational age and parity. METHODS: The women were examined during pregnancy and three months after delivery. Left ventricular function was assessed by echocardiography, including tissue-Doppler imaging. Endothelial function was assessed by measuring flow-mediated dilation of the brachial artery. MAIN OUTCOME MEASURES: Early diastolic mitral annular tissue velocity, "e", peak systolic tissue velocity, "S", and flow-mediated dilation. RESULTS: The diastolic function was reduced in preeclampsia, with lower "e", and there was a higher ratio of early diastolic mitral inflow velocity and early diastolic mitral annular velocity, "E/e". Early diastolic mitral inflow deceleration time and isovolumetric relaxation time were similar between the groups, suggesting pseudonormalization and increased filling pressures in preeclampsia. "S" was lower in the preeclampsia group during pregnancy. Both diastolic and systolic left ventricular functions normalized postpartum. The flow-mediated dilation was impaired in the preeclampsia group both during pregnancy and three months after delivery. CONCLUSIONS: The maternal left ventricular function was impaired during preeclampsia but had normalized three months after delivery. The endothelial function, measured by flow-mediated dilation, was impaired in the preeclampsia group as compared with the normal pregnancy group both during pregnancy and three months after delivery.

Aerobic interval training compensates age related decline in cardiac function.

OBJECTIVES: To study the effect of aerobic interval training (AIT) on myocardial function in sedentary seniors compared to master athletes (MA) and young controls. DESIGN: Sixteen seniors (72 ± 1 years, 10 men) performed AIT (4 × 4 minutes) at ≈ 90% of maximal heart rate three times per week for 12 weeks. Results were compared with 11 male MA (74 ± 2 years) and 10 young males (23 ± 2 years). RESULTS: Seniors had an impaired diastolic function compared to the young at rest. AIT improved resting diastolic parameters, increased E/A ratio (44%, p <0.01), early diastolic tissue Doppler velocity (e') (11%, p <0.05) and e' during exercise (11%, p <0.01), shortened isovolumic relaxation rate (IVRT) (13%, p <0.01). Left ventricle (LV) systolic function (S') was unaffected at rest, whereas S' during stress echo increased by 29% (p <0.01). Right ventricle (RV) S' and RV fractional area change (RFAC) increased (9%, p <0.01, 12%, p =0.01, respectively), but not RV e'. MA had the highest end-diastolic volume, stroke volume, diastolic reserve and RV S'. CONCLUSION: AIT partly reversed the impaired age related diastolic function in healthy seniors at rest, improved LV diastolic and systolic function during exercise as well as RV S' at rest.

Aerobic interval training increases peak oxygen uptake more than usual care exercise training in myocardial infarction patients: a randomized controlled study.

OBJECTIVE: Exercise capacity strongly predicts survival and aerobic interval training (AIT) increases peak oxygen uptake effectively in cardiac patients. Usual care in Norway provides exercise training at the hospitals following myocardial infarction (MI), but the effect and actual intensity of these rehabilitation programmes are unknown. DESIGN: Randomized controlled trial. SETTING: Hospital cardiac rehabilitation. SUBJECTS: One hundred and seven patients, recruited two to 12 weeks after MI, were randomized to usual care rehabilitation or treadmill AIT. INTERVENTIONS: Usual care aerobic group exercise training or treadmill AIT as 4 × 4 minutes intervals at 85-95% of peak heart rate. Twice weekly exercise training for 12 weeks. MAIN MEASURES: The primary outcome measure was peak oxygen uptake. Secondary outcome measures were endothelial function, blood markers of cardiovascular disease, quality of life, resting heart rate, and heart rate recovery. RESULTS: Eighty-nine patients (74 men, 15 women, 57.4 ± 9.5 years) completed the programme. Peak oxygen uptake increased more (P = 0.002) after AIT (from 31.6 ± 5.8 to 36.2 ± 8.6 mL·kg(-1)·min(-1), P < 0.001) than after usual care rehabilitation (from 32.2 ± 6.7 to 34.7 ± 7.9 mL·kg(-1)·min(-1), P < 0.001). The AIT group exercised with significantly higher intensity in the intervals compared to the highest intensity in the usual care group (87.3 ± 3.9% versus 78.7 ± 7.2% of peak heart rate, respectively, P < 0.001). Both programmes increased endothelial function, serum adiponectin, and quality of life, and reduced serum ferritin and resting heart rate. High-density lipoprotein cholesterol increased only after AIT. CONCLUSIONS: AIT increased peak oxygen uptake more than the usual care rehabilitation provided to MI patients by Norwegian hospitals.

Moderate continuous or high intensity interval exercise in heart failure with reduced ejection fraction: Differences between ischemic and non-ischemic etiology.

Background: Exercise for heart failure (HF) with reduced ejection fraction (HFrEF) is recommended by guidelines, but exercise mode and intensities are not differentiated between HF etiologies. We, therefore, investigated the effect of moderate or high intensity exercise on left ventricular end-diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF) and maximal exercise capacity (peak VO2) in patients with ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM). Methods: The Study of Myocardial Recovery after Exercise Training in Heart Failure (SMARTEX-HF) consecutively enrolled 231 patients with HFrEF (LVEF ≤ 35 %, NYHA II-III) in a 12-weeks supervised exercise program. Patients were stratified for HFrEF etiology (ICM versus NICM) and randomly assigned (1:1:1) to supervised exercise thrice weekly: a) moderate continuous training (MCT) at 60-70 % of peak heart rate (HR), b) high intensity interval training (HIIIT) at 90-95 % peak HR, or c) recommendation of regular exercise (RRE) according to guidelines. LVEDD, LVEF and peak VO2 were assessed at baseline, after 12 and 52 weeks. Results: 215 patients completed the intervention. ICM (59 %; n = 126) compared to NICM patients (41 %; n = 89) had significantly lower peak VO2 values at baseline and after 12 weeks (difference in peak VO2 2.2 mL/(kg*min); p < 0.0005) without differences between time points (p = 0.11) or training groups (p = 0.15). Etiology did not influence changes of LVEDD or LVEF (p = 0.30; p = 0.12), even when adjusting for sex, age and smoking status (p = 0.54; p = 0.12). Similar findings were observed after 52 weeks. Conclusions: Etiology of HFrEF did not influence the effects of moderate or high intensity exercise on cardiac dimensions, systolic function or exercise capacity. Clinical Trial Registration­URL: http://www.clinicaltrials.gov. Unique identifier: NCT00917046.

Peak systolic velocity indices are more sensitive than end-systolic indices in detecting contraction changes assessed by echocardiography in young healthy humans.

AIMS: It remains to be proven whether left ventricular (LV) peak systolic velocity indices (peak systolic annulus tissue velocities, ejection velocity, and strain rate) are more closely related to contraction than LV end-systolic echocardiographic indices (ejection fraction, fractional shortening, systolic annulus displacement, global strain, and ejection velocity time integral). The study aimed to compare the ability of different echocardiographic methods in detecting contraction changes of the LV. METHODS AND RESULTS: Thirty-three healthy volunteers (20-32 years) were examined by echocardiography at rest, during 10 µg/kg/min dobutamine (n = 20), and after injection of 15 mg metoprolol (n = 20). The effects of dobutamine and metoprolol on peak systolic velocity indices and end-systolic indices were compared. The relative increase from rest to dobutamine stress and the relative decrease after injection of metoprolol were 62 and -15% for peak systolic annulus tissue velocity, 60 and -11% for LV outflow tract (LVOT) peak velocity, 56 and -11% for peak systolic strain rate, 25 and 1% for ejection fraction, 30 and -1% for systolic mitral annulus displacement, 30 and -5% for LVOT velocity time integral, and 21 and -3% for global strain, respectively. The changes of the peak systolic indices were significantly higher (all P < 0.05) than the changes of the end-systolic indices. CONCLUSION: Peak systolic velocity indices (mitral annulus tissue velocities, ejection velocities, and strain rate) exhibited greater variation than end-systolic indices during inotropic alterations from which it is assumed that they better reflected LV contraction.

Echocardiography without electrocardiogram.

AIMS: automatic detection of the QRS complex on electrocardiogram (ECG) is used on cardiac ultrasound scanners to separate ultrasound image series into cardiac cycles for playback and storage. On small hand-held scanners it is unpractical to connect ECG cables. We therefore aim to do automatic cardiac cycle separation using apical B-mode ultrasound images. METHODS AND RESULTS: cardiac cycle length is estimated by cyclicity analysis of B-mode intensities. To determine a cycle start estimate near QRS, a deformable model is fitted to the left ventricle in real-time. The model is used to initialize and constrain a speckle tracker positioned near the mitral annulus. In the displacement curve generated by the speckle tracker, a time point near maximum distance from the probe is detected as a cardiac cycle start estimate. Validation against ECG was done on 233 recordings from normal subjects and 46 recordings from subjects with coronary pathology. Several test cases were run for each recording to emulate B-mode series starting at all time points in the cardiac cycle. Totally, 11 886 test cases were run. Cycle length estimation was feasible in 98% of normal subject cases and 91% of pathology cases. Median difference in cycle length by ECG was 0 and -3 ms, respectively. Cycle start estimation was feasible in 90% of normal subject cases and 77% of pathology cases. Median difference to cycle start by ECG was 62 and 76 ms, respectively. CONCLUSION: apical B-mode series can automatically be separated into cardiac cycles without using ECG.

Longitudinal strain and strain rate by tissue Doppler are more sensitive indices than fractional shortening for assessing the reduced myocardial function in asphyxiated neonates.

The function of the heart was studied in 20 asphyxiated term neonates by measuring the longitudinal peak systolic strain and peak systolic strain rate by tissue Doppler in 18 segments of the heart on days 1, 2, and 3 of life. The fractional shortening was assessed at each examination as well. Measurements were compared against measurements in 48 healthy term neonates examined by the same protocol. The function of the heart was lower in the asphyxiated neonates - peak systolic strain (mean (95% confidence interval) -19.4% (-20.4, -18.5), peak systolic strain rate -1.65 (-1.74, -1.56) per second) than in the healthy term neonates (peak systolic strain -21.7% (-22.3, -21.0), peak systolic strain rate -1.78 (-1.84, -1.74) per second; p < 0.001). Fractional shortening was similar in the asphyxiated (29.2% (26.8, 31.5)) and healthy term neonates (29.0% (27.9, 30.1); p = 0.874). The peak systolic strain differed significantly between the asphyxiated and healthy term neonates for the left basal and right basal groups of segments (p < 0.05) but not for the left apical, right apical, septum apical, or septum basal groups of segments. The peak systolic strain rate differed significantly only for the septum apical group of segments. The differences were largest on the second day of life. Measurements were similar in asphyxiated neonates with elevated and normal cardiac troponin T levels. The peak systolic strain and strain rate were in this study more sensitive indices than fractional shortening for assessing the reduced myocardial function in asphyxiated term neonates.