Abstract Background Detection of haemodynamically significant shunting from atrial septal defect (ASD) can be identified by using the pulmonary-systemic flow ratio (Qp/Qs). However, calculation of Qp/Qs by echocardiography relies on geometric assumptions that outflow tracts are circular, suffers from squared linear measures, and accurate measurement of right ventricular outflow tract (RVOT) diameter is challenging. Whilst adults with ASD should have overt right ventricular dilatation, RV sizing on echocardiography is often subjective and underappreciated. We evaluated whether a dimensionless index of flow (VTI) differences between the RVOT and left ventricular outflow tract (LVOT) could assist in identifying patients with ASD, and compared it with relative atrial index (RAI), a parameter previously assessed in identifying atrial shunting. Methods Data from 64 consecutive patients who underwent ASD closure and had no concomitant lesions, were compared with 63 normal controls. RVOT VTI, LVOT VTI, LVOT diameter, and atrial areas were measured. Results Between controls and ASD patients, there was no difference in LVOT VTI or forward stroke volume, but ASD patients had significantly higher RVOT VTI. The RVOT-LVOT VTI ratio was 1:1 in controls and 1.5:1 in ASD patients. Area under the ROC curve analysis of RVOT-LVOT VTI ratio was 0.83, and a ratio of 1.1:1 predicted patients with ASD with 86% sensitivity and 73% specificity. In comparison, the area under the ROC curve analysis of RAI was 0.70, and an RAI of 1.05:1 predicted patients with ASD with 77% sensitivity and 44% specificity. Conclusion Calculation of the dimensionless RVOT-LVOT VTI ratio is simple, and may be a useful additional semi-quantitative tool to assist cardiologists and sonographers in detecting atrial shunting, particularly in patients with borderline or overt right heart dilatation, and identify who patients should undergo further evaluation. Funding Acknowledgement Type of funding sources: None.

Abstract Introduction Pulmonary vein(PV) assessment is an integral component of the transthoracic echocardiogram(TTE) examination; typically assessed in the apical four-chamber view(A4Ch). There is disagreement in current textbooks and literature regarding which specific right pulmonary vein is visualised on A4Ch; as either the right superior(RSPV) or right inferior PV(RIPV). Given the high reliability of cardiac CT for PV assessment, we aimed to characterize right PV anatomy on A4Ch by utilizing multi-modality comparison of echocardiography and a 3D-guided A4Ch on CT. Methods Retrospective analysis was performed on consecutive patients with TTE demonstrating PV flow(by colour or pulse-wave Doppler) and cardiac CT within 30days; studies not meeting image quality criteria excluded. To simulate the A4Ch on CT, multi-planar reconstruction was used to create an image plane including right PV ostia and LV apex. This image was rotated along the long-axis to achieve an A4Ch with both ventricles and atria, tricuspid and mitral valves in view without LVOT or aorta. This was attempted for right superior, inferior and middle(RMPV, if present) PV’s. Results 50 patients were analysed: mean age 66yrs, 48% female, mean LA volume(indexed) 43.5ml/m². A4Ch was feasible in 100%(n = 50) of CT simulations using the RIPV, only 24%(n = 12) were feasible using RSPV with all excluded cases due to LVOT/aorta persistently in view. RMPV was present in 6 cases with feasible A4ch in 67%. Conclusion This study demonstrates that the right PV on A4Ch is highly likely to be the RIPV due to the RSPV being anatomically impossible in the significant majority of cases. Abstract P889 Figure. CT multiplanar reconstruction of A4Ch

Introduction: Pulmonary vein (PV) assessment is an integral component of the transthoracic echocardiogram (TTE) examination; typically assessed in the apical four-chamber view (A4Ch). There is disagreement in current textbooks and literature regarding which specific right pulmonary vein is visualised on A4Ch; as either the right superior (RSPV) or right inferior PV (RIPV). Given the high reliability of cardiac CT for PV assessment, we aimed to characterise right PV anatomy on A4Ch by utilising multi-modality comparison of echocardiography and 3D-guided A4Ch on CT. Methods: Retrospective analysis was performed on consecutive patients with TTE demonstrating PV flow (by colour or pulse-wave Doppler) and cardiac CT within 30 days; studies not meeting image quality criteria were excluded. To simulate the A4Ch on CT, multi-planar reconstruction was used to create an image plane including right PV ostia and LV apex. This image was rotated along the long-axis to achieve an A4Ch with both ventricles and atria, tricuspid and mitral valves in view without LVOT or aorta. This was attempted for right superior, inferior and middle (RMPV, if present) PVs. Results: 50 patients were analysed: mean age 66 yrs, 48% female, mean LA volume (indexed) 43.5 ml/m2. A4Ch was feasible in 100% (n = 50) of CT simulations using the RIPV, only 24% (n = 12) were feasible using RSPV with all excluded cases due to LVOT/aorta persistently in view. RMPV was present in 6 cases with feasible A4ch in 67%. Conclusion: This study demonstrates that the right PV on A4Ch is highly likely to be the RIPV due to the RSPV being anatomically impossible in the significant majority of cases.

Background: Failure to increase left ventricular ejection fraction (LVEF) post-exercise may be seen in the absence of established causes in patients with suspected obstructive coronary artery disease (OCAD) investigated with exercise stress echocardiography. This is associated with long-axis left ventricular dysfunction, however, cardiovascular outcomes of patients with such an abnormal contractile response are unknown. Aim: To determine long-term major adverse cardiovascular events in patients with failure to increase LVEF post-exercise. Methods: Amongst 1275 patients with suspected obstructive coronary artery disease (OCAD) undergoing both exercise stress echocardiography and anatomic coronary imaging, failure to increase LVEF post-exercise was observed in 138 (11%) patients in the absence of established causes. The primary endpoint was defined as major adverse cardiovascular events (MACE: composite endpoint of cardiac mortality, acute myocardial infarction, new heart failure, life threatening ventricular arrhythmias, coronary artery revascularisation and stroke) at 5-year follow-up. Results: Twenty-eight percent experienced MACE (53% with OCAD). Patients in MACE group, compared to those without MACE, were older (72 ± 7 vs. 62 ± 10 years, P < 0.0001), predominantly male (47% vs. 24%, P = 0.016), and had higher prevalence of hypertension (90% vs. 61%, P = 0.003); diabetes (37% vs. 20%, P = 0.06) and dyslipidemia (60% vs. 42%, P = 0.09). On multivariate analysis, older age (OR = 1.12, 95% CI = 1.06–1.20, P < 0.0001) and hypertension (OR = 4.5, 1.16–17.5, P = 0.03), but not OCAD (OR = 1.25, 0.48–3.26, P = 0.647) were independent predictors of MACE. Conclusion: Patients with failure to increase LVEF post-exercise have a high incidence of MACE at 5-year follow-up. Older age and hypertension predicts MACE in this population independent of coronary anatomy. The study indicates that the clinical trajectory of patients with this abnormal response is not benign and warrants long-term surveillance.

Background: Quantification of mitral regurgitation (MR) by echocardiogram (echo) remains challenging. In particular, calculation of differential flow across the mitral annulus and left ventricular outflow tract (LVOT) suffers from squared linear measures and the incorrect assumption that the LVOT and mitral annulus are flat and round. More than 10 years ago Tribouilloy et al. suggested a pulsed-wave Doppler velocity time integral (VTI) ratio between the mitral leaflet tips (MV) and LVOT as a geometrically independent, semi-quantitative tool to reflect differential flow in MR, with a MV to LVOT VTI ratio >1.3 indicative of severe MR. We evaluated this approach in patients with primary and secondary MR.

Background: When performed by trained clinicians, focused cardiac ultrasound (FCU) protocols can answer specific diagnostic questions in selected patients. The clinical utility of FCU in the management of non–cardiology medical inpatients remains unclear.

Background: The cardiovascular phenotype in Turner Syndrome (TS) includes high rates of aortic dilatation and bicuspid aortic valve (BAV). Due to short stature, aortic diameter index (ascending aortic diameter/BSA, ADI) is currently used to identify TS patients with aortic dilatation.

Introduction: Heart failure with reduced left ventricular ejection fraction (HFREF) and atrial arrhythmias (Atrial Fibrillation/Flutter) often co-exist, and the relationship between reduced ejection fraction (LVEF) and the uncontrolled heart rate (HR) is unclear. Objective: To explore the factors associated with recovery of LVEF in patients presenting with both atrial arrhythmia and reduced LVEF (<45%). Methods: Patients with HFREF and atrial arrhythmia admitted to a specialist HFREF clinic were included. Treatment was according to Heart Failure guidelines; atrial arrhythmias were managed at physician's discretion. Demographic, clinical and echocardiographic data were collected at baseline and follow up. Patients with improved LVEF (>10% increase) were compared to patients with unchanged LVEF. Results: 45 patients (64±12 years, 24% female, baseline LVEF 25±9%) were included. At 9±5 months follow-up 47% (n=21) demonstrated improved LVEF (repeat EF 48±8%, p<0.01). Improved LVEF pts had greater reduction in HR compared with unchanged LVEF pts (-42±24 vs –8±16 bpm, p<0.01). Increase in LVEF correlated with reduction in HR (r -0.59) regardless of rhythm. Pts with improved LVEF were less likely to have hypertension, documented IHD or diabetes (all p<0.01). Left atrial size was similar between groups (p=0.51) but improved LVEF had smaller LVEDD (p=0.04) and higher mitral annular velocities (p=0.01) at baseline. Conclusions: In patients presenting with HFREF and atrial arrhythmias, improved heart rate control was associated with improvement in LVEF, regardless of rhythm. LVEF was also more likely to improve in those without coronary artery disease, hypertension or diabetes.

Background: Global longitudinal strain (GLS) is a sensitive marker of LV dysfunction that facilitates early detection of cancer therapeutics related cardiac dysfunction (CTRCD). Standard GLS is derived from 3 apical views. However, as patients require repeated testing and CTRCD is a diffuse process, single view GLS could improve efficiency. We sought whether 4-chamber view GLS (4CV_LS) could substitute GLS for the detection of CTRCD. Methods: 108 cancer patients receiving Anthracycline-based chemotherapy were enrolled. Ejection fraction (EF), GLS and 4CV_LS were measured at baseline and follow-up, and the differences between them were calculated. Asymptomatic CTRCD was defined as EF > 0.10 decrease with to <0.55, or GLS > 12% decrease. A Bland-Altman plot (BA plot) was used for evaluation of concordance. Results: There were good correlations between GLS and 4CV_LS at baseline and follow-up (r = 0.86 and 0.89, both p < 0.0001). BA plots demonstrated minimal bias (0.21 at baseline; 0.03 at follow-up) but modest limits of agreement (2.54% and 2.19%). Of 47 patients developing CTRCD, 4CV_LS yielded 15 (14%) false negatives and 9 (8%) false positives, resulting in a discordance rate of 22% to detect CTRCD (Figure). Conclusions: 4CV_LS has good correlation with GLS, but our study indicates it could lead to significant misdiagnoses. We recommend standard GLS from multiple apical views for patients with risk for CTRCD.

Background: Global longitudinal strain (GLS) is a robust marker of LV function. However, the existing evidence base is mainly from experts and little is known on the effect of the learning curve. We sought to elucidate whether levels of experience affected the precision of GLS. Methods: 58 readers measured GLS of the same cases. Readers were divided by experience into 4 groups: No experience (n=13, 0 cases experience, Grp No), Limited experienced (n=12, 1-20 cases), intermediate (n=10, 21-100 cases), and experienced (n=23, experience with >100 cases, Grp High). Averaged GLSs from 5 highly experienced readers with >1000 cases experience were used as a reference and compared with those from the 4 groups. Mean difference (MD), standard deviation (SD), coefficient of variation (CV), and Intraclass correlation coefficients (ICCs) were used to determine concordance. Results: The ICC of Grp No was very good (0.975 [.912, .998]), that of Grp High was better (0.996 [.988, 1.000], p=0.0002). Progressively more experience led to progressively less variability (Figure). The MD, SD and CV of Grp High was significantly smaller than that of Grp No. Conclusions: Although inexperienced readers demonstrated high concordance, more experience reduces GLS variability and increases precision.

Longitudinal left ventricular (LV) systolic function is impaired in heart failure with preserved ejection fraction (EF), with reductions reported in both global longitudinal strain (GLS) and the peak systolic velocity of mitral annular motion (s‘) using tissue Doppler imaging (TDI). However, the significance of GLS versus s’ is incompletely understood. To investigate whether LV end-diastolic length (LVEDL), mitral annular systolic excursion (MASE) and heart rate might moderate the relationship between GLS and s’ we studied subjects with a low peak early diastolic TDI velocity (e‘) but normal EF. GLS was measured using speckle tracking. TDI measurements were averages from the septal and lateral walls. There were 88 subjects of age 66±8 years, (31 males, 64 with hypertension and 54 with diabetes) with septal and lateral e’ < 6 cm/s. The body mass index (BMI) was 29.1±4.1 kg/m2, heart rate was 72±9/min, blood pressure was 137±17/80±10 mmHg, EF was 61±6%, GLS was -17.4±2.7%, septal and lateral s’ were 6.1±1.1 and 6.8±1.5 cm/s, respectively and septal and lateral e’ were 4.2±1.0 and 5.2±0.9 cm/s, respectively. On univariate analysis EF was correlated with GLS (r=-0.48) but not with s’, MASE or e’ (p>0.05 for all). However, both s’ and MASE became positive correlates of EF in combination with LVEDL, which was a significant inverse correlate of EF (p<0.05 for all). s’ was modestly correlated with MASE (r2 = 0.37), but the prediction of s’ was improved in a multivariate model with the addition of heart rate to MASE (r2 =0.52). e’ was correlated with s’ (r2=0.09), but was more closely correlated with MASE (r2=0.18). On multivariate analysis, GLS was inversely correlated with MASE and positively correlated with LVEDL and BMI (r2=0.38, p<0.01 for all). In conclusion, in subjects with low e‘, GLS is more closely related to MASE than to s’ and is independently related to MASE, LVEDL and BMI.

Objective: To assess the feasibility and efficacy of inter-departmental cooperation in the establishment of a training and internal accreditation process for Monash Health Emergency Department (ED) physicians in Basic Echocardiography in Life Support (BELS). Methods: Over an 8-week period eight emergency physicians underwent a 1 hour BELS induction program before performing independent scans with ongoing support from a grade 4 cardiac sonographer. The BELS assessment included categorical assessment of ventricular size and function and detection of pericardial effusion (Peff). The emergency physician's echocardiography findings were compared with a blinded expert cardiologist using Cohen's kappa coefficient. Results: Of 57 consecutive scans performed, 55 were diagnostic for LV size and function, and all were suitable for assessment of Peff. The observed unweighted Kappa coefficient for LV function was 0.59, for LV size 0.64, and presence of Peff 0.79. There were 3 false negative and 4 false positive findings for LV function; 3 false negatives and no false positives for LV dilation; 1 false negative and 2 false positives for Peff. Conclusion: Emergency physicians participating in an interdepartmental program for BELS were able to acquire echocardiographic scans in the ED with a high proportion of diagnostic images. After only limited training, accuracy was high for the detection of Peff, but more moderate for assessment of left ventricular size and function. A cardiology-supported BELS training program has the potential to achieve rapid evaluation of limited cardiac pathology in the ED setting.

Introduction: Bicuspid aortic valve (BAV) is associated with higher rates of aortic regurgitation post transcatheter aortic valve replacement (TAVR). We sought to compare the aortic root geometry between BAV and trileaflet aortic valves (TAV). Methods: We evaluated BAV patients (confirmed echocardiographically) with previous 320-slice CT coronary angiogram over a 6-year period. Their annulus, left-ventricular outflow tract (LVOT), sinus of Valsalva (SoV) and ascending aorta (AA) were compared to matched TAV patients (age, sex and body surface area). Eccentricity index (EI) was calculated as 1 – minimum diameter/maximum diameter (Dmin/Dmax). Results: There were 67 BAV patients (66% male, mean age 43±12 years). BAV patients had larger diameters and area of LVOT, annulus, SoV and AA (Table). Interestingly, annulus in BAV was less eccentric/more circular (0.18 vs 0.21, p= 0.04). Conclusion: BAV patients have larger LVOT and aortic root measures than TAV, including a more circular shaped annulus. These differences may need to be considered when planning for TAVR in BAV patients.

Objective: Determine the impact of transoesophageal echocardiography (TOE) guidance on outcomes in patients undergoing TAVR with the repositionable Lotus valve. Introduction: Early in the TAVR experience, the procedure was largely performed with TOE guidance. Given the repositionability of the Lotus valve, TOE guidance and therefore general anaesthesia may be avoided. Methods: Consecutive patients undergoing TAVR (Lotus) were divided into 2 groups (TOE-guided and fluoroscopy-guided procedure). Data was collected on baseline demographics, peri-procedural complications and 30-day follow-up. The association between the presence of aortic regurgitation (AR) at 1 month and fluoroscopy guidance was assessed with a logistic regression analysis. Associations with procedural mortality, rates of procedural stroke/myocardial infarction (MI), permanent pacemaker (PPM) requirement, acute kidney injury (AKI), length of stay and need for rehabilitation were also assessed. Results: There were no significant differences in baseline characteristics between TOE (n=75) and fluoroscopy-guided (n=28) procedures (mean age 83.3 vs 82.8y, p 0.7). Fluoroscopy guidance was not associated with AR at 1 month (OR 0.72, CI 0.3-1.9, p 0.5). There were no differences in procedural mortality (0 in both groups), stroke (0 in both groups), MI (0 in both groups), PPM requirement (25% in both groups) or AKI (21 vs 24%, 0.7). There was also no difference in length of stay (5 vs 6 days, p 0.7) or need for rehabilitation (28 vs 25%, p 0.7). Conclusions: In a cohort with a low volume of fluoroscopy guided Lotus TAVR procedures, there appears to be no difference in outcomes compared with TOE-guidance.

Background: Functional capacity provides additional risk stratification and not been evaluated in chronic kidney disease (CKD) patients due a perceived inability of this population to exercise adequately. Functional capacity is an important predictor of perioperative outcomes therefore this study sought to evaluate the prognostic benefit of exercise stress echo(ESE) in CKD patients referred for cardiac risk evaluation prior to potential renal transplantation. Methods:469 consecutive patients underwent symptom-limited treadmill ESE and were followed for up to 4 years. Functional capacity was measured by metabolic equivalents (METs). The primary outcome was major adverse cardiovascular events (MACE). Results: There were 67 MACE: 31 deaths, 31 acute coronary syndromes, 5 strokes. Achievement of >7METs (n=403) was associated with improved survival compared to <7METs (n=66), (90% vs 76%, p=0.006, Figure 1). Abnormal ESE result or non-transplant status were associated with increased MACE. In a multivariate model incorporating age, gender, diabetes, known coronary disease, dialysis status, transplant status and ESE result, increasing METs (HR 0.83, 95%CI 0.72-0.95, p=0.008) was the strongest independent predictor of reduced MACE at follow-up. Conclusions: In CKD patients undergoing assessment for renal transplantation, functional capacity is associated with long-term MACE, independent of ESE result or transplant status.

Longitudinal systolic cardiac motion has been shown to be closely associated with carotid pressure wave inflection point timing in healthy volunteers, where the inflection point typically follows the systolic peak (Murgo Type C). The relationship between systolic myocardial motion and inflection point timing in patients with cardiovascular risk factors, where the inflection point precedes peak systolic pressure is unknown. Methods: 15 patients with cardiovascular risk factors underwent simultaneous carotid tonometry and Doppler tracking of medial mitral annular motion. Measurements were obtained at rest and following the administration of dobutamine (10mcg/kg/min) or GTN (400mcg sub-lingual). The ECG R-wave was used as a fiducial marker to determine the timing of both peak systolic mitral annular motion (S’) and the carotid pressure waveform inflection point. Results: 30 paired measurements were obtained. Dobutamine increased SBP, HR and pulse pressure whereas GTN decreased these parameters. Augmentation index decreased following both agents. The left ventricular outflow tract velocity time integral (indicative of stroke volume) increased with dobutamine and decreased with GTN. Despite these changes, the timing of peak S’ was significantly correlated with carotid inflection point timing both at rest and with pharmacological intervention (R=0.73, P=0.002 and R=0.89, P<0.001 respectively). Conclusions: Peak S’ timing (representing the commencement of myocardial deceleration in systole) always precedes and remains coupled to carotid pressure wave inflection point timing in older patients with established cardiovascular risk factors. This data suggests that central blood pressure waveform morphology may relate more strongly to local ventricular-vascular interactions, rather than wave reflections. Peak medial mitral annular velocity (S’) timing and carotid pressure waveform inflection point timing at rest (A) and following dobutamine / GTN (B). R = Spearman's Rank Correlation coefficient.

Introduction: Several risk factors for atrial fibrillation (AF) are long established including age, hypertension and left atrial volume (LAV). A more recently appreciated risk factor for AF is obesity. Hypothesis: We hypothesize that increased weight associates independently with atrial fibrillation. Methods: The database of all trans-thoracic echocardiograms (TTE) performed in a single cardiology department was interrogated for the five year period January 1, 2010 - December 31, 2014. Cardiac rhythm, age, sex, LAV, height, weight, systolic and diastolic BP data were extracted. Duplicate studies were removed. Data were analysed according to cardiac rhythm (AF vs sinus rhythm (SR)) by univariate comparisons (t tests) and multivariate linear regression. Results: 39,023 studies were analysed [age 61±17 years, 52.8% male]. In 3,993 studies (10.2%) the cardiac rhythm was AF. The group with AF were older (74±11 vs 59±17 yrs, p<10 -20 ), heavier (81.6±20.7 vs 78.6±20.0 kg, p<10 -19 ), more likely male (58.9 vs 52.1%, p<10 -15 ) and had larger LA volumes (71±33 vs 40±14 mL/m2, p<10 -20 ) than those in SR. Height (166±11cm) was not different (p=0.69). A multivariate linear regression model was constructed incorporating age, LAV, weight, sex, diastolic and systolic BP (R 2 =0.28, p<10 -20 ). In this model, weight was confirmed as an independent factor associated with AF (co-efficient 0.09, p<10 -20 ). Conclusions: Patients with AF were 3.0 kg heavier than those in SR. Weight remained independently associated with AF in the multivariate model. These retrospective observational data lend support to recent compelling data from a prospective randomised clinical trial showing that weight loss improved control of AF.

Introduction: Left atrial appendage (LAA) anatomy may predict embolic risk in AF, and accurate LAA measurements are required for implantation of LAA occlusion devices. LAA imaging is primarily by 2-dimensional transoesophageal echocardiography (2D-TOE); however, 2D-TOE assessment is limited by constrained imaging planes, which may be overcome by cardiac computed tomography (CCT). We compared 2D-TOE assessment of LAA orifice and depth with CCT measures, and performed volumetric analysis using CT in AF patients. Methods: 55 patients (70.1±10.2yrs, 34 male) with persistent AF underwent clinically indicated CCT. 320-slice CCT images of the LA and LAA were acquired. A subgroup of 21 patients underwent TOE for LAA sizing prior to percutaneous LAA occlusion. 2D-TOE visualised the LAA through 180° with images acquired at 0°, 45°, 90° and 135°; 3-D CT datasets were manipulated to provide identical planar LAA views. Results: CT-derived LA and LAA volumes were 184±71 ml and 15±7 ml respectively, and were moderately correlated (r=0.76, p<0.001). Maximum LAA orifice diameter (22.1±4.6 vs. 31.1±5.8 mm) and depth (31.8±7.2 vs. 41.0±10.5 mm) on 2D-TOE were smaller than on CT (p<0.001). LAA orifice eccentricity on CCT was 0.60±0.14. There was moderate correlation between techniques for diameter (r=0.59, p<0.01) and depth (r=0.76, p<0.01). Greatest discrepancies were at 0° (6.5±2.1 mm) and 135° (6.0±2.4 mm); agreement was closer at 45° (3.6±2.4 mm) and 90° (3.5±0.2 mm, all p <0.01). Conclusions: In AF patients, LAA size moderately correlates with LA volume. 2D-TOE significantly underestimates LAA diameter and depth in comparison with CT. These findings may have implications for imaging assessment prior to percutaneous LAA occlusion.

Background: LAV is an important marker of prognosis but is not routinely evaluated by cardiac magnetic resonance (CMR) as full volume dataset acquisition is time consuming. Calculation of LAV using the biplane area-length method (BAL) from routinely acquired 4 and 2-chamber views (4CV, 2CV) significantly underestimates true volume. Aim: We hypothesised this underestimation was due to standard CMR 4CV and 2CV images piloted from mid-mitral valve to LV apex – (LV-piloting) foreshortening the atrium, and additional 4CV and 2CV images piloted from mid-mitral valve to the mid posterior wall of the left atrium (LA-piloting) would enable rapid, accurate calculation of LAV using BAL. Methods: We evaluated 3-D datasets from 44 consecutive patients undergoing retrospective 320-CTCA. True 3-D left atrial volume (gold-standard) was calculated at end-systole by a blinded observer excluding pulmonary veins and left atrial appendage. A second blinded observer manipulated images to create standard ‘CMR’ 4CV and 2CV piloted from mid-mitral valve to LV apex (LV-piloted) enabling measurement of LAV using BAL. The dataset was then manipulated/’re-piloted’ from mid-mitral valve to the middle of posterior LA (LA piloted) and LAV was re-measured. Results: LV-piloted 4CV and 2CV images significantly underestimated true LAV (see table). Mean LAV from LA-piloted images was not significantly different from true LA volume and there was a strong correlation between the 2 with narrow confidence intervals. Conclusion: Accurate calculation of LAV can be made using BAL method from LA-piloted images, and is superior to calculation from standard LV-piloted images. Addition of two LA-piloted images to a standard CMR protocol may enable rapid and accurate calculation of an important prognostic marker for cardiovascular disease.Tabled 1ViewMean±SD (mL)95% CICorrelation to 3D-LAV(r-value)Mean difference to 3D-LAV(p-value)3D LAV82±24LV-piloted67±28(-19,-12)0.898<0.001LA-piloted81±27(-5,1)0.9220.27 Open table in a new tab

Introduction: Stress echocardiography (SE) is recommended for the investigation of coronary ischaemia in patients with non-interpretable ECGs, including left bundle branch block (LBBB) in various AHA/ACC guidelines. However data on the diagnostic accuracy of stress echocardiography in patients with LBBB is variable. We describe our experience in a large volume tertiary referral centre. Methods: We evaluated consecutive patients with resting L-BBB referred for SE to investigate for obstructive coronary artery disease (OCAD) at our institution. The left ventricular contractile response (LVCR) to stress was categorised as normal or abnormal. Patients with an abnormal response were sub categorised as (a) regional ischaemic response, (b) global hypokinetic response with fall in ejection fraction and (c) regional response equivocal for ischaemia. Subsequent coronary anatomic imaging (angiography or CTCA) results were evaluated. Results: There were 121 patients (52% females, mean age 63). Only 43 patients (36%) had a normal LVCR to exercise. Seventy-eight (64%) had an abnormal LVCR. Of these there were 39 with a global hypokinetic response, 16 a regional ischaemic response and 23 an abnormal regional response equivocal for ischaemia. Eighteen patients with an abnormal LVCR had anatomic imaging, eight were diagnosed with obstructive CAD, and 11 had no obstructive CAD. Conclusion: Contrary to the AHA/ACC guidelines, SE is a sub optimal test to evaluate for OCAD in patients with a LBBB, as the majority of patients will have an abnormal LVCR to exercise and thus OCAD cannot be excluded. We suggest alternate testing e.g. CT coronary angiography.