Lynsey Forsythe

A meta-analysis for the echocardiographic assessment of right ventricular structure and function in ARVC: a Study by the Research and Audit Committee of the British Society of Echocardiography

Introduction Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited pathology that can increase the risk of sudden death. Current task force criteria for echocardiographic diagnosis do not include new, regional assessment tools which may be relevant in a phenotypically diverse disease. We adopted a systematic review and meta-analysis approach to highlight echocardiographic indices that differentiated ARVC patients and healthy controls. Methods Data was extracted and analysed from prospective trials that employed a case–control design meeting strict inclusion and exclusion as well as a priori quality criteria. Structural indices included proximal RV outflow tract (RVOT1) and RV diastolic area (RVDarea). Functional indices included RV fractional area change (RVFAC), tricuspid annular systolic excursion (TAPSE), peak systolic and early diastolic myocardial velocities (S′ and E′, respectively) and myocardial strain. Results Patients with ARVC had larger RVOT1 (mean ± s.d.; 34 vs 28 mm, P < 0.001) and RVDarea (23 vs 18 cm2, P < 0.001) compared with healthy controls. ARVC patients also had lower RVFAC (38 vs 46%, P < 0.001), TAPSE (17 vs 23 mm, P < 0.001), S′ (9 vs 12 cm/s, P < 0.001), E′ (9 vs 13 cm/s, P < 0.001) and myocardial strain (−17 vs −30%, P < 0.001). Conclusion The data from this meta-analysis support current task force criteria for the diagnosis of ARVC. In addition, other RV measures that reflect the complex geometry and function in ARVC clearly differentiated between ARVC and healthy controls and may provide additional diagnostic and management value. We recommend that future working groups consider this data when proposing new/revised criteria for the echocardiographic diagnosis of ARVC.

The relationship between left ventricular structure and function in the elite rugby football league athlete as determined by conventional echocardiography and myocardial strain imaging

AIMS The aims of this study were to establish the left ventricular (LV) phenotype in rugby football league (RFL) athletes and to mathematically model the association between LV size, strain (ɛ) and ejection fraction (EF). METHODS AND RESULTS 139 male athletes underwent echocardiographic LV evaluation including ɛ imaging. Non-athletic males were used for comparison. All absolute and scaled structural indices were significantly larger (P < 0.05) in athletes with a predominance for normal LV geometry. EF and global ɛ were similar between groups but strain rates (SR) were significantly lower (P < 0.05) in athletes. Lower apical rotation (P < 0.001) and twist (P = 0.010) were exhibited in athletes. CONCLUSION Normal EF is explained by divergent effects of LV internal diastolic dimension (LVIDd) and mean wall thickness (MWT) on LV function. Reductions in SR and twist may be part of normal physiological LV adaptation in RFL athletes.

120 Left Ventricular Longitudinal Strain-Volume Relationships in Elite Athletesd

Introduction It is well established that left ventricular (LV) adaption occurs in response to chronic physiological conditioning. There is also evidence highlighting functional differences in myocardial strain imaging between athletes from sporting disciplines. This difference may be a consequence of the vague classification of sport i.e. not taking into account relative static and dynamic components and/or merely a consequence of chamber enlargement. We sought to utilise a novel simultaneous assessment of longitudinal strain and LV volume in athletes classified in the 4 corners of Mitchell’s classification of sporting disciplines. The primary aim was to determine relative longitudinal strain throughout the cardiac cycle and its specific contribution to LV volume change in these athletes. Methods 92 elite male athletes were studied and sub classified based on sporting discipline in accordance with the Mitchell’s classification. (Group IA low static-low dynamic n = 20, Group IC low static-high dynamic n = 25, Group IIIA high static-low dynamic n = 21, Group IIIC high static-high dynamic n = 26). Conventional echocardiography of the LV was undertaken. The raw temporal global longitudinal strain values were exported and divided into 5% time increments across the cardiac cycle. Concomitant LV volumes were traced at each 5% time increment to provide simultaneous strain-volume loops. The strain-volume relationship was assessed by applying a polynomial regression analysis for each systolic and diastolic curve to derive absolute values for% end diastolic volumes (EDV). Results Conventional and peak strain indices are presented in table 1. Athletes in group IC and IIIC had larger LV end diastolic volumes (EDV) compared to athletes in groups IA and IIIA (50 ± 6 and 54 ± 8 ml/(m2)1.5 vs. 42 ± 7 and 43 ± 2 ml/(m2)1.5 respectively). Group IIIC also had significantly larger mean wall thickness (MWT) compared to all groups. Peak strain was variable between groups but once normalised for EDV all groups, with exception of IIIC, required similar strain to generate the same% reduction in EDV (see Figures 1 and 2). Conversely group IIIC required greater longitudinal strain for any given% volume which correlated to MWT (r = 0.4, p < 0.0001).Abstract 120 Table 1 Echocardiographic Parameters PARAMETER GROUP IA GROUP IC GROUP IIIA GROUP IIIC LVDd index (mm/(m2)0.5) 37 ± 3† 39 ± 3 37 ± 3† 40 ± 2*‡ LVEDV index (ml/(m2)1.5) 42 ± 7^† 50 ± 6*‡ 43 ± 2^† 54 ± 8*‡ EF (%) 60 ± 7 58 ± 7 59 ± 5 59 ± 7 MWT index (mm/(m2)0.5) 6.0 ± 0.4† 6.3 ± 0.6 6.3 ± 0.6 6.7 ± 0.7* MaxWT index (mm/(m2)0.5) 6.6 ± 0.7† 7.0 ± 0.7† 7.1 ± 0.7 7.6 ± 0.9*^ LV Mass Index (g/(m)2.7) 33 ± 8† 37 ± 8 35 ± 9† 42 ± 9*‡ LVMass/LVEDV (g/ml) 1.4 ± 0.2 1.4 ± 0.3 1.4 ± 0.3 1.5 ± 0.3 Longitudinal Strain (%) -20 ± 3^‡ -16 ± 2*† -18 ± 2*† -20 ± 3^‡ Symbol denotes P > 0.05 to IA=*, IC=^, IIIA=‡, IIIC=†Abstract 120 Figure 1 Temporal Assessment of Simultaneous Strain and VolumeAbstract 120 Figure 2 Derived Strains for% EDV in the EF range 10 to 70% Conclusion There are physiological differences between athletes with the largest LV demonstrated in athletes from group IIIC. These athletes also have greater resting longitudinal contribution to volume change which, in part, is related to an increased wall thickness. The variance in peak strain seen in the other athlete groups was solely related to chamber size with no intrinsic differences in contractility or relaxation.

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

ABSTRACT 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.

Layer-specific strain in hypertensive patients with and without mild diastolic dysfunction

This study sought to examine layer-specific longitudinal and circumferential systolic and diastolic strain, strain rate (SR) and diastolic time intervals in hypertensive patients with and without diastolic dysfunction. Fifty-eight treated hypertensive patients were assigned to normal diastolic function (NDF, N = 39) or mild diastolic dysfunction (DD, N = 19) group. Layer-specific systolic and diastolic longitudinal and circumferential strains and SR were assessed. Results showed no between-group difference in left ventricular mass index (DD: 92.1 ± 18.1 vs NDF: 88.4 ± 16.3; P = 0.44). Patients with DD had a proportional reduction in longitudinal strain across the myocardium (endocardial for DD −13 ± 4%; vs NDF −17 ± 3, P < 0.01; epicardial for DD −10 ± 3% vs NDF −13 ± 3%, P < 0.01; global for DD: −12 ± 3% vs NDF: −15 ± 3, P = 0.01), and longitudinal mechanical diastolic impairments as evidenced by reduced longitudinal strain rate of early diastole (DD 0.7 ± 0.2 L/s vs NDF 1.0 ± 0.3 L/s, P < 0.01) and absence of a transmural gradient in the duration of diastolic strain (DD endocardial: 547 ± 105 ms vs epicardial: 542 ± 113 ms, P = 0.24; NDF endocardial: 566 ± 86 ms vs epicardial: 553 ± 77 ms, P = 0.03). Patients with DD also demonstrate a longer duration of early circumferential diastolic strain (231 ± 71 ms vs 189 ± 58 ms, P = 0.02). In conclusion, hypertensive patients with mild DD demonstrate a proportional reduction in longitudinal strain across the myocardium, as well as longitudinal mechanical diastolic impairment, and prolonging duration of circumferential mechanical relaxation.

The impact of preload reduction with head-up tilt testing on longitudinal and transverse left ventricular mechanics: a study utilizing deformation volume analysis

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 1 min, which was further augmented at 5 min (P = 0.018). Conclusions Preload reduction occurs within 1 min of HUT but does not further reduce at 5 min. 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.

Speckle Tracking Echocardiography for the Assessment of the Athlete’s Heart: Is It Ready for Daily Practice?

Purpose of reviewTo describe the use of speckle tracking echocardiography (STE) in the biventricular assessment of athletes’ heart (AH). Can STE aid differential diagnosis during pre-participation cardiac screening (PCS) of athletes?Recent findingsData from recent patient, population and athlete studies suggest potential discriminatory value of STE, alongside standard echocardiographic measurements, in the early detection of clinically relevant systolic dysfunction. STE can also contribute to subsequent prognosis and risk stratification.SummaryDespite some heterogeneity in STE data in athletes, left ventricular global longitudinal strain (GLS) and right ventricular longitudinal strain (RV ɛ) indices can add to differential diagnostic protocols in PCS. STE should be used in addition to standard echocardiographic tools and be conducted by an experienced operator with significant knowledge of the AH. Other indices, including left ventricular circumferential strain and twist, may provide insight, but further research in clinical and athletic populations is warranted. This review also raises the potential role for STE measures performed during exercise as well as in serial follow-up as a method to improve diagnostic yield.

121 The 12-lead Electrocardiogram of The Elite Rugby Football League Player

Introduction Specific ECG criteria have been proposed to differentiate physiology (athlete¡¯s heart) from pathology that may increase the risk of sudden cardiac death. Although the current European Society of Cardiology (ESC) guidelines have clear criteria for physiological adaptation to intense training, their sensitivity and specificity are sub-optimal and hence the more recent Seattle and Refined criteria have attempted to improve diagnostic accuracy of the athlete¡¯s ECG. Rugby Football League (RFL) is a moderate dynamic and moderate static sport with recent high profile fatalities linked to inherited cardiomyopathy. This study utilises resting 12-lead ECG, in elite RFL players to compare 3 sets of diagnostic ECG criteria in the athlete and specifically false positive rates. Methods 103 consecutive, male, elite RFL players (mean age 25¡À4 years) underwent pre-participation cardiac screening. Participants were predominantly white Caucasian (n = 81) with a minority of ethnic backgrounds being represented (Pacific Islander, n = 16; mixed race, n = 5; African-Caribbean, n = 1). All athletes had resting blood pressure assessed and a standard resting 12-lead ECG. In addition all athletes had a standard transthoracic echocardiogram and where indicated further investigations were undertaken. Standard ECG parameters were measured and the ESC recommendations for interpretation of 12-lead ECG in the athlete were used to define normal training (Group 1) and abnormal (Group 2) changes. All ECG¡¯s were also assessed for normality using the Seattle and Refined criteria. False-positive rates were presented for each ECG criteria. Results Based on ECG, echocardiography and/or follow-up investigation all athletes were considered normal with no evidence of underlying cardiac disease. The continuous ECG measurements are shown in Table 1. According to ESC criteria 95% of athletes had at least one group 1 “normal training-related” ECG change. 58% of athletes had at least one Group 2 ¡®abnormal training-related¡¯ change. This is therefore a false positive rate of 58%. Following application of the revised Seattle and Refined criteria the false-positive rates reduced to 5% and 3% respectively (Table 2).Abstract 121 Table 1 Continuous ECG variables of 103 elite RFL players Continuous ECG variables Mean ¡À SD(Range) Heart Rate (bpm) 54 ¡À 9(39–89) P Duration (ms) 105 ¡À 16(58–176) PR Interval (ms) 174 ¡À 26(129–309) QRS Duration (ms) 95 ¡À 12(11–123) QT Corrected (ms) (Bazett) 381 ¡À 20(338–442) QRS Axis (degrees) 61 ¡À 32(-46–117)Abstract 121 Table 2 % Training unrelated ECG changes for ESC, Seattle and Refined Criteria (% False Positive Rate) ECG Abnormality False Positive Rate (%) ESC Criteria Seattle Criteria Refined Criteria Long QTc Interval 1 0 0 Short QTc Interval 44 0 Not Relevant Intraventricular conduction delay (IVCD) 5 0 1 Right atrial enlargement (RAE) 1 0 1 Right ventricular hypertrophy (RVH) 3 0 3 Right axis deviation (RAD) 1 0 1 Left axis deviation (LAD) 3 3 3 T wave Inversion 1 1 1 ¡Ý2 PVC¡¯s per 10s tracing Not Relevant 1 1 False Positive Rate according to Criteria 58 5 3 Conclusion A significant proportion of RFL players present with an abnormal, non-training related, 12-lead ECG according to ESC criteria. In the cardiac screening setting this would result in significant extra cardiac investigation burden. Application of the Seattle and refined criteria decreased the false-positive rate and hence improves ECG specificity in this population.

119 The Effect of Preload Reduction Using Head-Up Tilt Testing: An Exploratory Study Using Left Ventricular Longitudinal and Transverse Strain-Volume Loops

Introduction Left ventricular (LV) function is dependent on intrinsic contractility and relaxation as well as the prevailing loading conditions. The Frank-Starling mechanism states that absolute myocardial shortening would be lower in the presence of a reduced preload, however LV function is complex and must adapt in this setting in order to maintain stroke volume and cardiac output. The impact of preload reduction on cardiac mechanics has been scarcely explored however the direct relationship of strain (s) in different planes and simultaneous volume assessment has not been assessed. This exploratory study utilises a novel technique (s-volume loops) in order to establish the relative temporal contribution of longitudinal (Ls) and transverse strain (Ts) to volume change throughout the cardiac cycle following 1 and 5 min of head-up tilt testing. Methods Five healthy subjects underwent standard transthoracic echocardiography to obtain an apical 4 chamber orientation with a focus on the LV in a supine position and following 1 min and 5 min of head-up tilt testing. As well as a standard assessment, raw temporal Ls and Ts values were exported and divided into 5% time increments across the cardiac cycle. Concomitant LV volumes were traced at each 5% time increment to provide simultaneous s-volume loops. The s-volume relationship was assessed by 1) polynomial equations to derive absolute strain values for% end diastolic volumes (EDV) and 2) systolic�diastolic coupling (SDcoup) as the difference between systolic and diastolic strain within the same working range of% EDV. Results There was a significant reduction in EDV at 1 min of head-up tilting (92�16ml Vs. 64�6ml) with no further change at 5 min. There was no significant change in EF or effective stroke volume. There was a reduction in peak Ls at 1 min tilting (-16�1 Vs. -12�1%) which remained stable at 5 min. Conversely, there was a gradual increase in Ts across time (16�3 Vs. 37�11%) as well as a gradual reduction in the time to peak Ts. Following calculation of s-volume loops the paradoxical relationship of reduced Ls and a concomitant increase in Ts remained at all 10% increments of EDV. There was a marked increase in Ts SDcoup at all 10% EDV increments at 5 min post tilt. Conclusion Preload reduction as a consequence of head-up tilt testing results in a shift in cardiac mechanics with a reduction in longitudinal and concomitant increase in transverse contribution to volume reduction and maintenance of EF. The systolic-diastolic coupling suggests that LV filling in the setting of a reduced preload is maintained by a greater return to original length of the myocardium in the transverse plane for any given volume. These findings provide important physiological value when assessing LV function in the clinical setting where a reduction in preload is evident.Abstract 119 Table 1 Conventional echocardiographic indices at supine, 1 minute and 5 minutes of head-up tilting Conventional Parameters SUPINE 1 MIN TILT 5 MIN TILT Heart Rate (bpm) 77 � 6 90 � 9* 87 � 6^ Systolic Blood Pressure (mmHg) 127 � 8 125 � 10 127 � 7 Diastolic Blood Pressure (mmHg) 76 � 7 79 � 15 83 � 5 Cardiac Output (l/min) 4.3 � 0.6 3.9 � 0.2 3.8 � 0.7 End Diastolic Volume (ml) 92 � 16 64 � 6* 69 � 11^ End Systolic Volume (ml) 37 � 7 20 � 6 * 25 � 7 LV Ejection Fraction (%) 60 � 4 69 � 7 63 � 6 E Wave Velocity (m/s) 0.81 � 0.19 0.78 � 0.09 0.70 � 0.10 A Wave Velocity (m/s) 0.55 � 0.11 0.59 � 0.08 0.66 � 0.26 E/A 1.5 � 0.6 1.3 � 0.2 1.2 � 0.6Abstract 119 Figure 1 Longitudinal and transverse strain-volume loops at supine and at 5 minutes head-up tilting