The impact of preload reduction with head-up tilt testing on longitudinal and transverse left ventricular mechanics.

BACKGROUND: Left ventricular (LV) function is dependent on load, intrinsic contractility and relaxation with a variable impact on specific mechanics. Strain (ε) imaging allows the assessment of cardiac function however the direct relationship between volume and strain is currently unknown. The aim of this study was to establish the impact of preload reduction through head-up tilt (HUT) testing on simultaneous left ventricular (LV) longitudinal and transverse function and their respective contribution to volume change. METHODS: A focused transthoracic echocardiogram was performed on 10 healthy male participants (23 ± 3 years,) in the supine position and following 1 min and 5 min of HUT testing. Raw temporal longitudinal ε (Ls) and transverse ε (Ts) values were exported and divided into 5% increments across the cardiac cycle and corresponding LV volumes were traced at each 5% increment. This provided simultaneous LV longitudinal and transverse ε and volume-loops (deformation-volume analysis - DVA). RESULTS: There was a leftward- shift of the ε -volume loop from supine to 1 min and 5 min of HUT, p<0.001). Moreover, longitudinal shortening was reduced (p<0.001) with a concomitant increase in transverse thickening from supine to 1min, which was further augmented at 5min (p=0.018). CONCLUSIONS: Preload reduction occurs within 1 minute of HUT but does not further reduce at 5 minutes. This decline is associated with a decrease in longitudinal ε and concomitant increase in transverse ε. Consequently, augmented transverse relaxation appears to be an important factor in the maintenance of LV filling in the setting of reduced preload. DVA provides information on the relative contribution of mechanics to a change in LV volume and may have a role in the assessment of clinical populations

Reproducibility and feasibility of right ventricular strain and strain rate (SR) as determined by myocardial speckle tracking during high-intensity upright exercise: a comparison with tissue Doppler-derived strain and SR in healthy human hearts.

This study aimed to establish feasibility for myocardial speckle tracking (MST) and intra-observer reliability of both MST and tissue velocity imaging (TVI)-derived right ventricular (RV) strain (ϵ) and strain rate (SR) at rest and during upright incremental exercise. RV ϵ and SR were derived using both techniques in 19 healthy male participants. MST-derived ϵ and SR were feasible at rest (85% of segments tracked appropriately). Feasibility reduced significantly with progressive exercise intensity (3% of segments tracking appropriately at 90% maximum heart rate (HRmax)). Coefficient of variations (CoVs) of global ϵ values at rest was acceptable for both TVI and MST (7-12%), with low bias and narrow limits of agreement. Global SR data were less reliable for MST compared with TVI as demonstrated with CoV data (systolic SR=15 and 61%, early diastolic SR=16 and 17% and late diastolic SR=26 and 31% respectively). CoVs of global RV ϵ and SR obtained at 50% HRmax were acceptable using both techniques. As exercise intensity increased to 70 and 90% HRmax, reliability of ϵ and SR values reduced with larger variability in MST. We conclude that RV global and regional ϵ and SR data are feasible, comparable and reliable at rest and at 50% HRmax using both MST and TVI. Reliability was reduced during higher exercise intensities with only TVI acceptable for clinical and scientific use

Influence of different dynamic sporting disciplines on right ventricular Structure and function in elite male athletes.

Our objective was to assess the influence of different levels of exposure to dynamic training on right ventricular (RV) structure, function and mechanics in elite male athletes. We recruited 492 male elite athletes aged between 18 and 30 years old. Athletes were grouped according to their sporting discipline using the Mitchell Classification as Low Dynamic (LD), Moderate Dynamic (MD) or High Dynamic (HD). All participants underwent 2D, Doppler, tissue Doppler and strain (ε) echocardiography with a focused and comprehensive assessment of the right heart. Athletes involved in MD sports had the largest absolute RV chamber size and when scaled to body size RVOT PLAX, RVOT2, RVD1 and RVD3 were larger in HD compared to MD and LD athletes. There were no between group differences in conventional RV functional indices as well as global RV ε (LD: - 23.4 ± 3.1 vs. MD: - 22.7 ± 2.7 vs. HD: - 23.5 ± 2.6, %) and strain rate (P > 0.01). The base to apex ε gradient in the RV septum was lower in the MD athletes compared to HD and LD due to a lower apical septal ε which significantly correlated with absolute RV chamber size. After scaling for body size there was evidence of larger RV cavities in both MD and HD athletes compared to LD athletes. Global RV function, ε and strain rate were not different between groups. MD athletes had lower apical septal ε that contributed to a smaller base-to-apex ε gradient that is partially associated with larger absolute RV chamber dimensions

Cardiac structure and function in elite Native Hawaiian and Pacific Islander Rugby Football League athletes: an exploratory study.

The aim of this exploratory study was to define the Athletes Heart (AH) phenotype in Native Hawaiian & Pacific Islander (NH&PI) Rugby Football League (RFL) athletes. Specifically, (1) to describe conventional echocardiographic indices of left ventricle (LV) and right ventricle (RV) structure and function in NH&PI RFL players and matched RFL Caucasian controls (CC) and (2) to demonstrate LV and RV mechanics in these populations. Ethnicity is a contributory factor to the phenotypical expression of the AH. There are no data describing the cardiac phenotype in NH&PI athletes. Twenty-one male elite NH&PI RFL athletes were evaluated using conventional echocardiography and myocardial speckle tracking, allowing the assessment of global longitudinal strain (ε) and strain rate (SR); and basal, mid and global radial and circumferential ε and SR. Basal and apical rotation and twist were also assessed. Results were compared with age-matched Caucasian counterparts (CC; n = 21). LV mass [42 ± 9 versus 37 ± 4 g/(m2.7)], mean LV wall thickness (MWT: 9.5 ± 0.7 and 8.7 ± 0.4 mm), relative wall thickness (RWT: 0.35 ± 0.04 and 0.31 ± 0.03) and RV wall thickness (5 ± 1 and 4 ± 1 mm, all p < 0.05) were greater in NH&PI compared with CC. LV and RV cavity dimensions and standard indices of LV and RV systolic and diastolic function were similar between groups. NH&PI demonstrated reduced peak LV mid circumferential ε and early diastolic SR, as well as reduced global radial ε. There was reduced basal rotation at 25-35% systole, reduced apical rotation at 25-40% and 60-100% systole and reduced twist at 85-95% systole in NH&PI athletes. There were no differences between the two groups in RV wall mechanics. When compared to Caucasian controls, NH&PI rugby players have a greater LV mass, MWT and RWT with concomitant reductions in circumferential and twist mechanics. This data acts to prompt further research in NH&PI athletes

Acute response and chronic stimulus for cardiac structural and functional adaptation in a professional boxer.

The individual response to acute and chronic changes in cardiac structure and function to intense exercise training is not fully understood and therefore evidence in this setting may help to improve the timing and interpretation of pre-participation cardiac screening. The following case report highlights an acute increase in right ventricular (RV) size and a reduction in left ventricular (LV) basal radial function with concomitant increase at the mid-level in response to a week's increase in training volume in a professional boxer. These adaptations settle by the second week; however, chronic physiological adaptation occurs over a 12-week period. Electrocardiographic findings demonstrate an acute lateral T-wave inversion at 1 week, which revert to baseline for the duration of training. It appears that a change in training intensity and volume generates an acute response within the RV that acts as a stimulus for chronic adaptation in this professional boxer

Left ventricular remodeling in elite and sub-elite road cyclists.

Marked adaptation of left ventricular (LV) structure in endurance athletes is well established. However, previous investigations of functional and mechanical adaptation have been contradictory. A lack of clarity in subjects' athletic performance level may have contributed to these disparate findings. This study aimed to describe structural, functional, and mechanical characteristics of the cyclists' LV, based on clearly defined performance levels. Male elite cyclists (EC) (n = 69), sub-elite cyclists (SEC) (n = 30), and non-athletes (NA) (n = 46) were comparatively studied using conventional and speckle tracking 2D echocardiography. Dilated eccentric hypertrophy was common in EC (34.7%), but not SEC (3.3%). Chamber concentricity was higher in EC compared to SEC (7.11 ± 1.08 vs 5.85 ± 0.98 g/(mL)2/3 , P < .001). Ejection fraction (EF) was lower in EC compared to NA (57 ± 5% vs 59 ± 4%, P < .05), and reduced EF was observed in a greater proportion of EC (11.6%) compared to SEC (6.7%). Global circumferential strain (GCε) was greater in EC (-18.4 ± 2.4%) and SEC (-19.8 ± 2.7%) compared to NA (-17.2 ± 2.6%) (P < .05 and P < .001). Early diastolic filling was lower in EC compared with SEC (0.72 ± 0.14 vs 0.88 ± 0.12 cm/s, P < .001), as were septal E' (12 ± 2 vs 15 ± 2 cm/s, P < .001) and lateral E' (18 ± 4 vs 20 ± 4 cm/s, P < .05). The magnitude of LV structural adaptation was far greater in EC compared with SEC. Increased GCε may represent a compensatory mechanism to maintain stroke volume in the presence of increased chamber volume. Decreased E and E' velocities may be indicative of a considerable functional reserve in EC

Chronic adaptation of atrial structure and function in elite male athletes

Aims The aim of this study was to establish the degree of structural and functional adaptations in the left (LA) and right atria (RA) in elite male athletes engaged in ‘high dynamic : high static’ (HDHS) and ‘low dynamic : high static’ (LDHS) sporting disciplines compared with sedentary controls. Methods and results Eighteen male, elite HDHS athletes (13 boxers and 7 triathletes), 18 male, elite LDHS athletes (8 weightlifters and 10 Akido), and 20 male, age-matched sedentary controls were assessed using conventional 2D and myocardial speckle tracking (MST) echocardiography. Absolute LA and RA volumes [end systole (VOLes), pre A (VOLpreA), and end diastole (VOLed)] as well as the functional indices of reservoir (RESvol), conduit (CONvol), and booster volumes (BOOvol) were defined. MST allowed the assessment of atrial strain (ε) during the reservoir (RESε), conduit (CONε), and booster (BOOε) phases of the cardiac cycle. Both LA and RA sizes were significantly larger in HDHS compared with LDHS and controls (P 1 in all groups due to a comparatively larger RA volume (RAVOLes : LAVOLes 1.05 ± 0.26, 1.12 ± 0.55, and 1.04 ± 0.28 for HDHS, LDHS, and controls, respectively, P > 0.05). There was no significant between group differences for any ε parameter. Conclusion Bi-atrial hypertrophy is demonstrated in HDHS athletes and not in LDHS athletes, suggesting that the dynamic component to training is the primary driver for both LA and RA adaptation. Although functional data derived from volume shifts suggest augmented function in HDHS athletes, MST imaging demonstrated no difference in intrinsic atrial ε in any of the groups

Exploratory assessment of right ventricular structure and function during prolonged endurance cycling exercise

BACKGROUND: A reduction in right ventricular (RV) function during recovery from prolonged endurance exercise has been documented alongside RV dilatation. A relative elevation in pulmonary artery pressure and therefore RV afterload during exercise has been implicated in this post-exercise dysfunction but has not yet been demonstrated. The current study aimed to assess RV structure and function and pulmonary artery pressure before, during and after a 6-h cycling exercise bout. METHODS: Eight ultra-endurance athletes were recruited for this study. Participants were assessed prior to exercise supine and seated, during exercise at 2, 4 and 6 h whilst cycling seated at 75% maximum heart rate, and post-exercise in the supine position. Standard 2D, Doppler and speckle tracking echocardiography were used to determine indices of RV size, systolic and diastolic function. RESULTS: Heart rate and RV functional parameters increased from baseline during exercise, however RV structural parameters and indices of RV systolic and diastolic function were unchanged between in-exercise assessment points. Neither pulmonary artery pressures (26 ± 9 mmHg vs 17 ± 10 mmHg, P > 0.05) nor RV wall stress (7.1 ± 3.0 vs 6.2 ± 2.4, P > 0.05) were significantly elevated during exercise. Despite this, post-exercise measurements revealed RV dilation (increased RVD1 and 3), and reduced RV global strain (- 21.2 ± 3.5 vs - 23.8 ± 2.3, P = 0.0168) and diastolic tissue velocity (13.8 ± 2.5 vs 17.1 ± 3.4, P = 0.019) vs pre-exercise values. CONCLUSION: A 6 h cycling exercise bout at 75% maximum heart rate did not alter RV structure, systolic or diastolic function assessments during exercise. Pulmonary artery pressures are not elevated beyond normal limits and therefore RV afterload is unchanged throughout exercise. Despite this, there is some evidence of RV dilation and altered function in post-exercise measurements

Exploratory insights from the right-sided electrocardiogram following prolonged endurance exercise.

BACKGROUND: Prolonged strenuous exercise has a profound effect on cardiac function. The right heart may be more susceptible to this imposition; yet, right-sided chest leads have not been utilised in this setting. METHODS: Thirty highly trained athletes at the 2014 Western States 100-mile Endurance Run from Squaw Valley to Auburn, California (body mass 68 ± 12 kg, age 45 ± 10 years, 57 ± 15 miles per week) were recruited for the study. Pre- and post-race, a right-sided 12-lead ECG was obtained and data were extracted for P, R and S waves, J point, ST segment and T wave amplitude. Data were compared using Students T-test and statistical significance set as P < .05. RESULTS: There was a significant increase in P wave amplitude (29%) and QTc interval (4%) pre- to post-race from standard 12-lead ECG. From the right-sided12-lead ECG, a 23% (P = .01) and 38% (P = .03) increase in J point amplitude in V1R and V2R and a 22% (P = .05) increase in ST segment integral in V2R and V3R were evident. T wave inversion was evident in leads V2R-V6R in 50-90% of athletes, respectively. Close examination revealed marked heterogeneity in individual ECGs. CONCLUSIONS: Completion of a 100-mile ultra-marathon resulted in significant changes in the right-sided ECG alongside more marked responses in specific individuals. P wave, ST segment and T wave changes post-race are indicative of acute exercise-induced right heart electrical adaptation

Right ventricular function in elite male athletes meeting the structural echocardiographic task force criteria for arrhythmogenic right ventricular cardiomyopathy.

Athlete pre-participation screening is focused on detecting pathological conditions like arrhythmogenic right ventricular cardiomyopathy (ARVC). The diagnosis of ARVC is established by applying the revised 2010 ARVC Task Force Criteria (TFC) that assesses RV structure and function. Some athletes may meet structural TFC without having ARVC but we do not know the consequences for RV function. This study compared RV structural and functional indices in male athletes that meet the structural TFC (MTFC) for ARVC and those that do not (NMTFC). We recruited 214 male elite athletes. All participants underwent 2D, Doppler, tissue Doppler and strain (ε) echocardiography with a focused and comprehensive assessment of the right heart. Athletes were grouped on RV structural data: MTFC n = 34; NMTFC n = 180. Functional data were compared between groups. By selection, MTFC had larger absolute and scaled RV outflow tract (RVOT) diameter compared to NMTFC (P ˂0.05) but these athletes did not develop a proportional increase in the RV inflow dimensions. There was no difference in global conventional RV systolic function between both groups however, there was significantly lower global RV ε in athletes that MTFC which can be explained, in part, by the RVOT dimension