Left Ventricular Lateral Wall Research Articles

Imaging predictors of response to cardiac resynchronization therapy: left ventricular work asymmetry by echocardiography and septal viability by cardiac magnetic resonance.

Aims Left ventricular (LV) failure in left bundle branch block is caused by loss of septal function and compensatory hyperfunction of the LV lateral wall (LW) which stimulates adverse remodelling. This study investigates if septal and LW function measured as myocardial work, alone and combined with assessment of septal viability, identifies responders to cardiac resynchronization therapy (CRT).Methods and results In a prospective multicentre study of 200 CRT recipients, myocardial work was measured by pressure-strain analysis and viability by cardiac magnetic resonance (CMR) imaging (n = 125). CRT response was defined as ≥15% reduction in LV end-systolic volume after 6 months. Before CRT, septal work was markedly lower than LW work (P < 0.0001), and the difference was largest in CRT responders (P < 0.001). Work difference between septum and LW predicted CRT response with area under the curve (AUC) 0.77 (95% CI: 0.70–0.84) and was feasible in 98% of patients. In patients undergoing CMR, combining work difference and septal viability significantly increased AUC to 0.88 (95% CI: 0.81–0.95). This was superior to the predictive power of QRS morphology, QRS duration and the echocardiographic parameters septal flash, apical rocking, and systolic stretch index. Accuracy was similar for the subgroup of patients with QRS 120–150 ms as for the entire study group. Both work difference alone and work difference combined with septal viability predicted long-term survival without heart transplantation with hazard ratio 0.36 (95% CI: 0.18–0.74) and 0.21 (95% CI: 0.072–0.61), respectively.ConclusionAssessment of myocardial work and septal viability identified CRT responders with high accuracy.

Right Ventricular Diastolic Dysfunction after Marathon Run.

It has been raised that marathon running may significantly impair cardiac performance. However, the post-race diastolic function has not been extensively analyzed. We aimed to assess whether the marathon run causes impairment of the cardiac diastole, which ventricle is mostly affected and whether the septal (IVS) function is altered. The study included 34 male amateur runners, in whom echocardiography was performed two weeks before, at the finish line and two weeks after the marathon. Biventricular diastolic function was assessed not only with conventional Doppler indices but also using the heart rate-adjusted isovolumetric relaxation time (IVRTc). After the run, IVRTc elongated dramatically at the right ventricular (RV) free wall, to a lesser extent at the IVS and remained unchanged at the left ventricular lateral wall. The post-run IVRTc_IVS correlated with IVRTc_RV (r = 0.38, p < 0.05), and IVRTc_RV was longer in subjects with IVS hypertrophy (88 vs. 51 ms; p < 0.05). Participants with measurable IVRT_RV at baseline (38% of runners) had longer post-race IVRTc_IVS (102 vs. 83 ms; p < 0.05). Marathon running influenced predominantly the RV diastolic function, and subjects with measurable IVRT_RV at baseline or those with IVS hypertrophy can experience greater post-race diastolic fatigue.

Evaluation of the effect of percutaneous mitral balloon valvuloplasty on left ventricular systolic functions using strain and strain rate echocardiography

Background/aimThis study aimed to evaluate the effect of successful percutaneous mitral balloon valvuloplasty (PMBV) on left ventricular systolic functions using strain and strain rate echocardiography in moderate–severe mitral stenosis (MS) patients with normal left ventricular systolic function confirmed by conventional echocardiography. Materials and methodsPatients with moderate–severe MS who had undergone successful PMBV were included. Conventional echocardiographic parameters were evaluated before and after PMBV. Peak systolic strain and strain rate values of basal, mid, and apical segments of the left ventricular anterior, inferior, septum, and lateral walls were determined. ResultsAfter PMBV, significant decreases were determined in the peak and mean gradients of the mitral valve and pulmonary artery pressure, but a significant increase in the mitral valve area. Significant increases (improvement) were determined in the peak systolic strain and strain rate in the basal, mid, and apical segments of the left ventricular septum, lateral, anterior, and inferior walls and in the left ventricular global peak systolic strain (–17.32 ± 0.58% vs. –12.38 ± 1.06%) and strain rate (–1.65 ± 0.07 vs. –1.22 ± 0.12). ConclusionStrain and strain rate echocardiography can be used for quantitative evaluation of the effect of PMBV on the left ventricular systolic functions in moderate–severe MS patients.

False Aneurysm of Left Ventricle after Nonpenetrating Chest Trauma: About one Case

Pseudoaneurysms of the left ventricle (LV) are most often due to ischemic origin but traumatic etiology, though rare, is possible. The latter is most often secondary to a penetrating chest trauma but the occurrence of pseudoaneurysms after no penetrating chest trauma is possible. We report the exceptional case of our patient admitted with dyspnea on exertion and palpitations appeared in the consequences of a no penetrating chest trauma by blow of hoof of horse occurred 3 years ago making discover a pseudoaneurysm of the left ventricular lateral wall opened in the pulmonary infundibulum. This clinical presentation shows the importance of echocardiography or chest CT scan to detect early this life-threatening complication, the management of which is well codified.

182-LB: Cardiovascular Response to Exercise in T2D

Type 2 diabetes (T2D) confers a greater likelihood of heart failure (HF) and hospitalization due to HF. Our group has reported sub-clinical cardiac dysfunction and aortic stiffness in youth and adults with uncomplicated T2D. As aortic stiffening is reported to precede HF and is common in people with uncomplicated T2D, we tested the hypothesis that aerobic exercise training will improve cardiac function and central arterial stiffness in people with T2D compared to participants of similar BMI without T2D. Sedentary adults with (n = 18, age 48±7, 45% female) and without (n = 20, age 45±7, 46% female) T2D, underwent MRI for cardiac function and aortic compliance (aortic relative area change [RAC] and pulse wave velocity [PWV]) before and after 15 weeks of aerobic exercise training. At baseline, both cohorts exhibit subclinical diastolic dysfunction, however, those with T2D had lower end-diastolic volume (EDVN,47.2±9.9 vs. 52.3±9.1 mL/m2) and end-systolic volume (ESVN,21.1±5.4 vs. 23.6±5.2 mL/m2), than controls. The T2D group had higher max thickness of the left ventricular (LV) septal wall (LVMTs, 10.5±1.8 vs. 9.3±1.6 mm) and LV lateral wall (LVMTl, 8.4±1.6 vs. 7.6±1.3 mm) than controls. Those with T2D also had lower RAC (12.7±1.6 vs. 20.2±1.6%) and higher PWV (7.4±1.3 vs. 3.9±0.6 m/s) than controls. Preliminary data in a subset post exercise intervention (n=7 with and n=8 without T2D), revealed increased EDVN(42.8±7.9 to 51.5±11.3 mL/m2) and ESVN(19.7±4.0 to 24.3±6.5 mL/m2) and decreased LVMTs(11.35±1.5 to 9.96±1.3 mm) and LVMTl(8.42±0.81 to 7.74±0.89 mm) in the T2D group, but cardiac endpoints were unchanged in controls. Post-intervention in both groups, ascending aorta RAC increased (control: 16.2±4 % to 18.5±1.7 and T2D: 10.6±1.7 % to 19.6±2.2 %) and PWV decreased (control: 6.3±2.0 to 3.4±0.3 and T2D: 8.0±1.4 to 2.9±0.7). Data from this study in progress suggest that adults with T2D have a greater degree of cardiac dysfunction and arterial stiffness than controls of similar BMI, which improve to a greater degree with exercise than in controls. Disclosure D. Enge: None. J.E. Reusch: None. J.G. Regensteiner: None. M. Schäfer: None. K.S. Hunter: None. A.J. Barker: None. K.J. Nadeau: None. R.L. Scalzo: None. I.E. Schauer: None. L. Abushamat: None. M.O. Whipple: None. D. Rafferty: None. Funding U.S. Department of Veterans Affairs (CX001532)

Quantitative cardiac magnetic resonance T2 imaging offers ability to non-invasively predict acute allograft rejection in children.

Monitoring for acute allograft rejection improves outcomes after cardiac transplantation. Endomyocardial biopsy is the gold standard test defining rejection, but carries risk and has limitations. Cardiac magnetic resonance T2 mapping may be able to predict rejection in adults, but has not been studied in children. Our aim was to evaluate T2 mapping in identifying paediatric cardiac transplant patients with acute rejection. Eleven paediatric transplant patients presenting 18 times were prospectively enrolled for non-contrast cardiac magnetic resonance at 1.5 T followed by endomyocardial biopsy. Imaging included volumetry, flow, and T2 mapping. Regions of interest were manually selected on the T2 maps using the middle-third technique in the left ventricular septal and lateral wall in a short-axis and four-chamber slice. Mean and maximum T2 values were compared with Student's t-tests analysis. Five cases of acute rejection were identified in three patients, including two cases of grade 2R on biopsy and three cases of negative biopsy treated for clinical symptoms attributed to rejection (new arrhythmia, decreased exercise capacity). A monotonic trend between increasing T2 values and higher biopsy grades was observed: grade 0R T2 53.4 ± 3 ms, grade 1R T2 54.5 ms ± 3 ms, grade 2R T2 61.3 ± 1 ms. The five rejection cases had significantly higher mean T2 values compared to cases without rejection (58.3 ± 4 ms versus 53 ± 2 ms, p = 0.001). Cardiac magnetic resonance with quantitative T2 mapping may offer a non-invasive method for screening paediatric cardiac transplant patients for acute allograft rejection. More data are needed to understand the relationship between T2 and rejection in children.

Ultrasound‐based estimation of remaining cardiac function in LVAD‐supported ex vivo hearts

Left ventricular assist devices (LVAD) provide cardiac support to patients with advanced heart failure. Methods that can directly measure remaining LV function following device implantation do not currently exist. Previous studies have shown that a combination of loading (LV pressure) and deformation (strain) measurements enables quantitation of myocardial work. We investigated the use of ultrasound (US) strain imaging and pressure–strain loop analysis in LVAD‐supported hearts under different hemodynamic and pump unloading conditions, with the aim of determining LV function with and without LVAD support. Ex vivo porcine hearts (n = 4) were implanted with LVADs and attached to a mock circulatory loop. Measurements were performed at hemodynamically defined “heart conditions” as the hearts deteriorated from baseline. Hemodynamic (including LV pressure) and radio‐frequency US data were acquired during a pump‐ramp protocol at speeds from 0 (with no pump outflow) to 10 000 revolutions per minute (rpm). Regional circumferential (εcirc) and radial (εrad) strains were estimated over each heart cycle. Regional ventricular dyssynchrony was quantitated through time‐to‐peak strain. Mean change in LV pulse pressure and εcirc between 0 and 10 krpm were −21.8 mm Hg and −7.24% in the first condition; in the final condition −46.8 mm Hg and −19.2%, respectively. εrad was not indicative of changes in pump speed or heart condition. Pressure–strain loops showed a degradation in the LV function and an increased influence of LV unloading: loop area reduced by 90% between 0 krpm in the first heart condition and 10 krpm in the last condition. High pump speeds and degraded condition led to increased dyssynchrony between the septal and lateral LV walls. Functional measurement of the LV while undergoing LVAD support is possible by using US strain imaging and pressure–strain loops. This can provide important information about remaining pump function. Use of novel LV pressure estimation or measurement techniques would be required for any future use in LVAD patients.

Animal Model of Cardiac Reperfusion Injury to Evaluate the Effects of Electrical Microcurrent Application: Preliminary Results

Reperfusion injury (RI) occurs after cardiac surgery, myocardial infarction or heart transplantation, however effective treatment strategies are still lacking. Cardiac micro intensity electrical current (C-MIC) modulates inflammation, myocardial remodeling and recovery in failing hearts in vivo and in vitro. This study aimed to establish a large animal model of RI to test C-MIC application on RI after cardiopulmonary bypass (CPB). Seven swines underwent CPB with 120 mins crossclamp time, and were assigned to a control (n=3) or treatment group (n=4). The treatment group received a C-MIC device consisting of an epicardial patch electrode placed on the left ventricular lateral free wall, a transvenous right ventricular counter electrode, and a current generator. C-MIC treatment was continued until CPB weaning. Reperfusion on full CPB flow lasted 20 mins, followed by a stepwise weaning process. Inotropes or pacing were not allowed. Noradrenaline was used to maintain arterial pressure and xylocaine for arrhythmia treatment. Defibrillation was performed as needed. Primary end-point was survival at 20 mins after CPB weaning. Baseline characteristics and pre-CPB hemodynamics were comparable between groups. All C-MIC devices were successfully implanted, without observed malfunction. A microcurrent in the upper µA range was delivered. In the C-MIC group, CPB weaning was successful in all animals, and survival with stable hemodynamics was observed in 50% of cases (Table 1). Weaning and survival rates were lower in the control group. Noradrenaline was required in 50% of the C-MIC animals and in 100% of control animals to maintain arterial pressure after CPB. Our study presents an animal model which allows evaluation of RI treatment strategies. In this pilot trial, the C-MIC device was safely and successfully implanted. Our data suggest a potential benefit of C-MIC treatment for RI and further studies are needed to test this promising therapy.

Left bundle branch block increases left ventricular diastolic pressure during tachycardia due to incomplete relaxation.

We investigated whether tachycardia in left bundle branch block (LBBB) decreases left ventricular (LV) diastolic distensibility and increases diastolic pressures due to incomplete relaxation, and if cardiac resynchronization therapy (CRT) modifies this response. Thirteen canines were studied at baseline heart rate (120 beats/min) and atrial paced tachycardia (180 beats/min) before and after induction of LBBB and during CRT. LV and left atrial pressures (LAP) were measured by micromanometers and dimensions by sonomicrometry. The time constant τ of exponential pressure decay and degree of incomplete relaxation at mitral valve opening (MVO) and end diastole (ED) based on extrapolation of the exponential decay were assessed. Changes in LV diastolic distensibility were investigated using the LV transmural pressure-volume (PV) relation. LBBB caused prolongation of τ (P < 0.03) and increased the degree of incomplete relaxation during tachycardia at MVO (P < 0.001) and ED (P = 0.08) compared with normal electrical activation. This was associated with decreased diastolic distensibility seen as upward shift of the PV relation at MVO by 18.4 ± 7.0 versus 12.0 ± 5.0 mmHg, at ED by 9.8 ± 2.3 versus 4.7 ± 2.3 mmHg, and increased mean LAP to 11.4 ± 2.7 versus 8.5 ± 2.6 mmHg, all P < 0.006. CRT shifted the LV diastolic PV relation downwards during tachycardia, reducing LAP and LV diastolic pressures (P < 0.03). Tachycardia in LBBB reduced LV diastolic distensibility and increased LV diastolic pressures due to incomplete relaxation, whereas CRT normalized these effects. Clinical studies are needed to determine whether a similar mechanism contributes to dyspnea and exercise intolerance in LBBB and if effects of CRT are heart rate dependent.NEW & NOTEWORTHY Compared with normal electrical conduction, tachycardia in left bundle branch block resulted in incomplete relaxation during filling, particularly of the late activated left ventricular lateral wall. This further resulted in reduced left ventricular diastolic distensibility and elevated diastolic pressures and thus amplified the benefits of cardiac resynchronization therapy in this setting.

Mechanical Effects on Right Ventricular Function From Left Bundle Branch Block and Cardiac Resynchronization Therapy

ObjectivesThe purpose of this study was to investigate how LBBB and CRT modify RV free wall function by direct ventricular interaction. BackgroundRight ventricular (RV) function influences prognosis in patients with left bundle branch block (LBBB) and cardiac resynchronization therapy (CRT). There is, however, limited insight into how LBBB and CRT affect RV function. MethodsIn 24 patients with LBBB with nonischemic cardiomyopathy, RV and left ventricular (LV) strain by speckle-tracking echocardiography was measured before and after CRT. Underlying mechanisms were studied in 16 anesthetized dogs with ultrasonic dimension crystals and micromanometers. ResultsPatients with LBBB demonstrated distinct early systolic shortening in the RV free wall, which coincided with the typical abnormal early systolic septal shortening. In animals, this RV free wall contraction pattern resulted in reduced myocardial work as a large portion of the shortening occurred against low pressure during early systole, coinciding with abnormal leftward septal motion. RV systolic function was maintained by vigorous contraction in the late-activated LV lateral wall, which pushed the septum toward the RV. CRT reduced abnormal septal motion and increased RV free wall work because there was less inefficient shortening against low pressure. ConclusionsLBBB reduces workload on the RV free wall because of abnormal septal motion and delayed activation of the LV lateral wall. Restoring septal and LV function by CRT increases workload in RV free wall and may explain why patients with RV failure respond poorly to CRT. (Contractile Reserve in Dyssynchrony: A Novel Principle to Identify Candidates for Cardiac Resynchronization Therapy [CRID-CRT]; NCT02525185)

P975 Echocardiography and nuclear medicine imaging techniques are insufficient for scar detection in patients referred for cardiac resynchronization therapy

Abstract Funding Acknowledgements The study was supported by Center for Cardiological Innovation Background Many patients referred for cardiac resynchronization therapy (CRT) do not respond to the treatment. Scar either in septum or the left ventricular (LV) lateral wall, as well as global scar burden, influence the outcome negatively. Preoperative scar assessment is therefore recommended in this patient group. Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is considered reference standard for scar detection, but is not always available. Purpose To investigate the ability of advanced echocardiographic and nuclear imaging techniques to detect septal and left ventricular (LV) lateral wall scar in patients referred for CRT, compared to late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR). Methods Scar was quantified as percentage segmental LGE in 131 patients (age 66 ± 10, 66% male, QRS-width 164 ± 17ms) referred for CRT, 92% with left bundle branch block (LBBB). Longitudinal strain was assessed by speckle tracking echocardiography in 130 patients (641 septal and 630 LV lateral wall segments). Wall motion score index (WMSI) was assessed visually in all patients by an experienced operator, and graded from one to four. Glucose metabolism was assessed by 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) in 52 patients. Perfusion was assessed in 46 patients by either 13N-ammonia PET (n = 32) or Single Photon Emission Computed Tomography (SPECT) (n = 14). Metabolism and perfusion were reported as percentages of the segment with maximum tracer uptake. The ability of each parameter to identify scar was evaluated with receiver operating characteristic (ROC) curves with calculation of area under the curve (AUC) and 95% confidence interval (CI). AUC≥0.800 was considered reasonable agreement with LGE. Results Scar was present in 574 of total 2090 interpretable segments (79% ischemic etiology). Globally, perfusion (AUC = 0.845, 95% CI 0.777-0.914) and glucose metabolism (AUC = 0.807, 95% CI 0.758-0.855) adequately detected transmural scars, but not smaller scars (all AUC &amp;lt; 0.800). Echocardiographic parameters failed to detect global scars irrespective of size (all AUC &amp;lt; 0.800). However, the associations between echocardiographic/nuclear parameters and scars were highly dependent on myocardial region. In the LV lateral wall, glucose metabolism precisely detected transmural scars (AUC = 0.958, 95% CI 0.902-1.00) and WMSI proved reasonable agreement (AUC = 0.812, 95% CI 0.737-0.887), while the rest of the parameters did not (all AUC &amp;lt; 0.800). Smaller scars in this region was not detected by any parameter tested (all AUC &amp;lt; 0.800). No parameter adequately detected septal scars, not even those with transmural involvement (all AUC &amp;lt; 0.800) (Figure). Conclusions Neither echocardiographic nor nuclear imaging techniques can replace LGE-CMR in scar assessment prior to CRT. Septum is especially challenging, explained by LBBB-induced reduction in strain, metabolism and perfusion in this region. Abstract P975 Figure. Detection of transmural septal scar

561 Targeting septal work and viability identifies responders to cardiac resynchronization therapy

Abstract Funding Acknowledgements The study was supported by Center for Cardiological Innovation. Introduction Septal dysfunction is the dominant mechanism of left ventricular (LV) failure in left bundle branch block (LBBB). We hypothesize that, provided septum is viable, septal function can recover and hence LV function improve after cardiac resynchronization therapy (CRT). Purpose To determine if combined assessment of septal function and viability identifies responders to CRT. Methods In a prospective multicenter study of 200 unselected patients referred for CRT, we measured myocardial strain by speckle-tracking echocardiography and regional work by pressure-strain analysis before and 7 ± 1 months after CRT. Viability was assessed by late gadolinium enhancement cardiac magnetic resonance imaging (n = 123). CRT response was defined as ≥15% reduction in LV end-systolic volume. Results Before CRT, septal work was 258 ± 463 and LV lateral wall work 1469 ± 674 mmHg·% (p &amp;lt; 0.0001). In CRT responders, septal work was restored to 1243 ± 495 mmHg·%, whereas non-responders showed less marked improvement (p &amp;lt; 0.0001). The figure illustrates a typical CRT responder with negative septal work and a large difference between work in the LV lateral wall and septum (panel A). There was no septal scar (panel B) and, after 6 months with CRT, septal work was recovered (panel C). Pressure-strain loops illustrate that CRT converted inefficient septal contractions with substantial negative (wasted) work to positive work throughout systole. For the entire study population, the difference between work in the LV lateral wall and septum predicted CRT response with area under the curve (AUC) 0.75 (95% CI: 0.68-0.83) and was feasible in 98% of patients. Furthermore, septal scar predicted non-response to CRT with AUC 0.76 (95% CI: 0.65-0.86). Combining work difference and septal viability improved AUC for CRT response to 0.85 (95% CI: 0.76-0.94) (figure panel D). The AUC was similar for QRS 120-150 and &amp;gt;150 ms. Conclusions The proposed combined approach with assessment of septal work and viability identified CRT responders with high precision. Abstract 561 Figure.

Clinical experience regarding safety and diagnostic value of cardiovascular magnetic resonance in patients with a subcutaneous implanted cardioverter/defibrillator (S-ICD) at 1.5\u2009T

BackgroundCardiovascular magnetic resonance (CMR) studies in patients with implanted cardioverter/defibrillators (ICD) are increasingly required in daily clinical practice. However, the clinical experience regarding the feasibility as well as clinical value of CMR studies in patients with subcutaneous ICD (S-ICD) is still limited. Besides safety issues, image quality and analysis can be impaired primarily due the presence of image artefacts associated with the generator.MethodsTwenty-three patients with an implanted S-ICD (EMBLEM, Boston Scientific, Marlborough, Massachusetts, USA; MR-conditional) with suspected cardiomyopathy and/or myocarditis underwent multi-parametric CMR imaging. Studies were performed on a 1.5 T CMR scanner after device interrogation and comprised standard a) balanced steady state free precession cine, b) T2 weighted-edema, c) velocity-encoded cine flow, d) myocardial perfusion, e) late-gadolinium-enhancement (LGE)-imaging and f) 3D-CMR angiography of the aorta. In case of substantial artefacts, alternative CMR techniques such as spoiled gradient-echo cine-sequences and wide-band inversion-recovery LGE (wb-LGE) sequences were applied.ResultsSuccessful CMR studies could be performed in all patients without any case of unexpected early termination or relevant technical complication other than permanent loss of the S-ICD system beeper volume in 52% of our patients. Assessment of cine-CMR images was predominantly impaired in the left ventricular (LV) anterior, lateral and inferior wall segments and a switch to spoiled gradient echo-based cine-CMR allowed an accurate assessment of cine-images in N = 17 (74%) patients with only limited artefacts. Hyperintensity artefacts in conventional LGE-images were predominantly observed in the LV anterior, lateral and inferior wall segments and image optimisation by use of the wb-LGE was helpful in 15 (65%) cases. Aortic flow measurements and 3D-CMR angiography were assessable in all patients Perfusion imaging artefacts precluded a meaningful assessment in at least one half of the patients. A benefit in clinical-decision making was documented in 17 (74%) patients in the present study.ConclusionSafe 1.5 T CMR imaging was possible in all patients with an S-ICD, though the majority had permanent loss of the S-ICD beeper volume. Achieving good image quality may be challenging in some patients - particularly for perfusion imaging. Using spoiled gradient echo-based cine-sequences and wb-LGE sequences may help to reduce the extent of artefacts, thereby allowing accurate cardiac assessment. Thus, 1.5 T CMR studies should not be withhold in patients with S-ICD for safety concerns and/or fear of extensive imaging artefacts precluding successful image analysis.

P1380 tissue Doppler and speckeled tracking of left ventricle post coarctation repair

Abstract Introduction Left ventricular dysfunction was observed after repair of coarctation of the aorta (COA) before development of left ventricular concentric hypertrophy. Aim The aim of this study was to assess the the LV functions after COA repair. Methods Thirty pediatric patients with COA repair underwent echocardiographic examinations using Conventional echocardiography, tissue doppler image (TDI) and 2D-STE. Results The LV systolic functions assessed by TDI and 2-D-STE showed a significant reduction of (S׳׳LW LV, IVA at LW LV, IVA at the septum, longtudinal strain (LS) basal and global radial (GRS) in cases compared to control group . There is significant increase in GCS in cases compared to control group, the conventional Doppler derived MPI of LV in post coarctation repair cases was significantly prolonged compared to control. Analysis of mitral annulus velocities including E", A", E"/A" ratio and E/E′ ratio revealed worsening of the left ventricular diastolic mechanics in the post COA repair cases compared to healthy controls. The E" wave velocity (at the left ventricular lateral wall) was significantly lower in post COA repair in cases compared with controls , E"/A" ratio was significantly lower in post COA repair cases compared with controls . The E/E′ ratio was significantly higher in the post COA repair cases compared to the control group . Conclusions LV systolic and diastolic dysfunction was fount in patient after COA repair. LV systolic function by 2-D-STE Cases Control P value Mean SD mean SD GLS -21.51 2.79 -22.63 2.99 .094 LS basal -19.94 2.83 -22.63 2.99 &amp;lt;0.01 (S) LS Mid -21.08 2.75 -21.87 2.78 .273 LS apical -23.52 4.22 -21.74 4.23 .109 GRS 22.58 5.24 49.01 10.08 &amp;lt;0.01 (S) RS basal 20.92 8.29 43.56 18.95 &amp;lt;0.01 (S) RS mid 25.03 7.59 56.80 14.27 .223 RS apical 21.78 8.34 46.66 15.11 &amp;lt;0.01 (S) GCS -20.09 2.66 -16.73 2.78 &amp;lt;0.01 (S) CS basal -21.49 2.70 -16.98 4.69 &amp;lt;0.01 (S) CS mid -21.27 4.09 -15.83 3.67 &amp;lt;0.01 (S) CS apical -17.51 4.63 -17.39 4.57 .920

546 Machine-learning based exploration of echocardiographic patterns and clinical parameters to understand their relation to death or transplant in pediatric dilated cardiomyopathy

Abstract Background Pediatric dilated cardiomyopathy (DCM) affects left ventricular (LV) function and carries a high risk of death or heart transplantation. However, the relation of LV regional function and inefficiency to clinical outcomes is underexplored. Purpose The aim of this study was to understand the relationship of regional LV mechanics, global LV function and clinical characteristics to the outcomes of death or heart transplant in children with DCM; through the integration of a vast amount of information enabled by unsupervised machine learning techniques. Methods DCM was defined by a LV end-diastolic dimension z-score &amp;gt; 2 and LV ejection fraction (EF) &amp;lt;55%. Longitudinal strain curves were sampled at 6 LV lateral wall and septal locations from the 4ch apical view. In addition, we analyzed other echo parameters including the aortic outflow pattern as a measure of LV pump function, QRS duration, LV EF, indexed end-diastolic LV dimension, global longitudinal strain and patient characteristics including age, weight, body surface area and medications (diuretics, ACE inhibitor, beta-blockers, mineralocorticoid receptor antagonist, digoxin, inotropes, antiarrhythmics). We used an unsupervised machine learning algorithm (multiple kernel learning) to reduce the dimensionality of these data, and position patients based on similarities. We subsequently used k-means clustering to recover homogeneous groups of patients. We then interpreted the data patterns associated to each of the groups for the occurrence of death or transplant through non-linear regression analysis (multi-scale kernel regression). Results 50 children with DCM (age 0 to 18 years) were analyzed. Clustering on the two first dimensions of the low-dimensional space resulted in three clusters (Figure A), with significantly different proportions of the composite outcome of death or heart transplant (Cl1 = 79%, Cl2 = 50%, Cl3 = 20%; p = 0.01). The group with the highest proportion of death or transplant (cluster 1) comprised the oldest and most frequently medicated subjects, with impaired LVEF and GLS, and with the widest QRS duration (p &amp;lt; 0.01) (Figure B). The group with the second highest proportion of death or transplant (cluster 2) comprised patients with the lowest LVEF (p &amp;lt; 0.01) and GLS (p &amp;lt; 0.001), reduced and delayed peak aortic outflow velocity and severely impaired basal and apical LV strain (Figure C). In contrast, the group with highest transplant-free survival (cluster 3) had the highest LVEF and GLS values, the most synchronous LV contraction as assessed by strain and QRS duration and the highest amplitude and earliest peaking aortic flow. Conclusion Our results serve as a proof-of-concept that machine-learning based approaches can be useful to explore and understand which regional and global echo parameters in combination with clinical parameters are associated with a higher risk of death or transplant in pediatric DCM. Abstract 546 Figure

102 Different mechanics of septal and lateral walls and their effects on left ventricular ejection fraction in patients with left bundle-branch block

Abstract Funding Acknowledgements Karolina Kupczynska was supported by research grant awarded by the Club 30 of the Polish Cardiac Society Background Left bundle branch block (LBBB) impairs left ventricular (LV) mechanics and can lead to systolic dysfunction. However, LV mechanical changes that differentiate LBBB patients with preserved and reduced LV ejection fraction (LVEF) remain to be clarified. Purpose To measure myocardial work (MWI) and myocardial work efficiency (MWE) of the septal and LV lateral wall in patients with LBBB and various degrees of LV dysfunction using non-invasive strain-derived method. Methods Fifty-eight LBBB patients without coronary artery disease (mean age 65 ± 13 years, 60% male) were divided into 4 groups based on their LVEF according to current recommendations for cardiac chamber quantification (figure A): normal (n= 25), mildly (n= 16), moderately (n= 11), and severely (n= 6) reduced LVEF. Septal and lateral wall MWI and MWE were estimated by LV pressure-strain loop obtained by echocardiography. Results Both MWI (787 mmHg%, 95% CI 651-924 vs 1956 mmHg%, 95% CI 1758-2154; p &amp;lt; 0.0001) and MWE (71%, 95% CI 66-76 vs 85%, 95% CI 82-87; p = 0.0001) were lower in the septum than in the lateral wall. There was a progressive decrease in septal MWI and MWE with the worsening of LVEF (figure B). Conversely, MWI and MWE of the lateral wall were preserved in patients with normal, mildly and moderately reduced LVEF groups. A significant reduction of MWI and MWE in the lateral wall was detected only in patients with severely reduced LVEF (figure C). Conclusion In patients with LBBB, impairment in septal myocardial work escalates according to LVEF loss. Septal dysfunction was compensated by the effective myocardial work of the lateral wall in patients with normal, mildly and moderately reduced LVEF. Mechanical dysfunction of the lateral wall was associated with severe reduction of LVEF. Abstract 102 Figure.

P1337 Left ventricle outpouchings. Assesing diagnostic complexity

Abstract Congenital left ventricle outpouchings (LVO) are a very rare condition that include left ventricle accessory chamber, left ventricle aneurysm (LVA), left ventricle diverticulum (LVD), double-chambered left ventricle and accessory left ventricle, without well-stablished diagnostic criteria. A recent article by Elaheh Malakan et al tries to show this difficulties and propose an algorithm to help define this different pathologies. We present the case of a 26-day-old boy that was admitted to our Hospital with suspicion of dilated cardiomyopathy. In his physical exam a systolic murmur was detected, and his mother described tiredness during intakes and tachypnea. His ECG showed a sinus rhythm, with an 80º QRS axis. No signs of hypertrophy or dilated cavities were detected. As part of the study a TTE was performed, detecting a dilated left ventricle with a tract crossing the apical side from the LV lateral wall. The MRI confirmed the presence of an incomplete muscular septum from de LV lateral wall up to the apex encompassing the papillary muscles in the mid left ventricle, dividing the LV in two chambers with telediastolic size of 3.5x3cm and 2.6x2.4cm respectively. This secondary appendix, with a pseudoaneurysm morphology, distended in systole with a dyskinetic motion. Globally, the left ventricle was dilated and had mild systolic disfunction. The right cavities were morphological and functionally normal. In this case initially a common dilated cardiomyopathy was suspected, being able to confirm the presence of a muscular tract crossing the mid left ventricle. The MRI described the image as an LV pseudoaneurysm, however the TTE images and the diagnostic algorithm proposed by Elaheh Malakan et al would include this case as a two-chamber left ventricle, denoting the still present difficulties in the diagnostic process in these cases, and its impact in their therapeutic approach. Abstract P1337 Figure.

P1736 An unexpected cause of ventricular tachycardia in a young patient

Abstract Introduction Hypoplastic coronary artery disease (HCAD) refers to a congenital underdevelopment of one or more coronary arteries, which are greatly reduced in diameter or length. It is a rare congenital abnormality which has rarely been documented in living patients and which may lead to myocardial infarction (MI) and sudden cardiac death (SCD). This case describes an otherwise healthy young male, which was admitted in the emergency department (ED) for repeated sustained ventricular tachycardia (VT) and was thereby diagnosed with an isolated hypoplasia of the left circumflex coronary artery (CX). Investigations revealed scar-related tachycardia, due to a prior silent myocardial infarction caused by HCAD. These findings were suggested by echocardiography and coronary angiography and were later confirmed by magnetic resonance and 3D cardiac mapping. Case Report A 34-year-old male patient was admitted to the intensive care unit with recurrent sustained VT causing hemodynamic instability. After receiving two electric shocks and amiodarone in the ambulance, the patient became hemodynamically stable. There was no remarcable medical history besides a syncopal fall 5 years before and no symptoms prior to the current event. Initial physical examination, ECG and laboratory testing were normal. Echocardiography revealed a dilated left ventricle with akynesia of the lateral wall and a mildly reduced ejection fraction (EF = 45%), moderate mitral regurgitation due to restriction of the posterior mitral leaflet. A subsequent emergent coronary angiography was therefore performed, which showed no sign of atherosclerotic lesions, yet it revealed a hypoplastic CX, without compensatory collateral vessels supplying the lateral wall. Cardiac MR demonstrated delayed enhancement with transmural necrosis and no viability in the lateral wall of the LV, suggesting a long-standing MI. Therefore, the final diagnosis was scar-related VT, due to a prior silent MI caused by HCAD. The management of this patient included implantation of an ICD in the secondary prevention of SCD. Moreover, we performed an EPS, which identified a scar at the level of the lateral and inferolateral LV walls as a substrate for VT (electroanatomic 3D voltage mapping) and of the critical istmus (3D activation mapping). The next step was radiofrequency ablation of the critical isthmus, with no inducibility of the VT after the procedure. After 6-months follow-up, there was no recurrence of the VT. Conclusion Finding the cause of myocardial infarction in a young patient with VT can be very challenging. We emphasise the role of imaging for the diagnosis and management of these patients. HCAD is a rare congenital anomaly, which can lead to progressive fibrosis in the territory with poor blood supply, MI and SCD. Although it is a rare condition, it should be considered in young adults who present with MI and/or SCD. Abstract P1736 Figure. Investigations

P242 When there is no time for further imaging

Abstract Introduction Cardiac tamponade (CT) is a clinical syndrome characterized by hemodynamic abnormalities resulting from an increase in pericardial pressure due to accumulation of fluid. Tamponade is one of the cardiac emergencies where urgent management steps are crucial and life saving. Absolute goal of treatment in Cardiac tamponade is to relieve the intra-pericardial pressure and to reverse the hemodynamic shutdown, by removal of the pericardial fluid via pericardiocentesis or surgical drainage. As much inevitable as it is, pericardiocentesis is relatively contraindicated when the effusion is associated with aortic dissection or myocardial rupture due to the potential risk of aggravating the dissection or rupture via rapid pericardial decompression and restoration of systemic arterial pressure. Case description A 44-year-Old transit passenger was admitted after she developed sudden onset of palpitations, vomiting and epigastric pain. She was in sinus tachycardia when brought to the Emergency department, within minutes’ patient went into cardiac shock with severe metabolic acidosis. She was admitted to ICU and subsequently intubated. Chest X-ray showed evidence of Pleural effusion with enlarged cardiac shadow, which prompted an urgent transthoracic echocardiogram. Echo findings were consistent with clinical cardiac tamponade with a large left pericardial mass compressing the lateral LV wall and aortic root, with a color flow from the mass toward the left coronary system. Mean while the patient was rapidly deteriorating, with and patient was not stable to undergo further imaging (CT or MRI), urgent contrast echo was done to rule out vascular connection between the mass and pericardial fluid, The Echo contrast study showed no vascular connection from the mass to the pericardial space ,however there was a connection from the mass to the left coronary system as shown in the figure, based on these findings a pericardial drainage was done successfully. These findings were confirmed by contrast CT scan after patient is stabilized. Patient gradually improved clinically, was extubated successfully, the provisional diagnosis was suspicious of pheochromocytoma,however the final diagnosis not established as the patient travelled to home country for further management. Conclusion Some times, it may become clinically challenging to effectively rule out contraindications to a procedure by the gold standard modalities, specially when a patient is collapsing on the table and the clock is ticking. In such scenarios, immediate alternate approaches resulting in safe outcomes are indispensable. Likewise, in our case of emergent cardiac tamponade and a suspicious pericardial mass in a crashing patient, Transthoracic echo with Optison proved to be life saving to rule out vascular connections between cardiac mass and coronaries or pericardial fluid, when there was no time for definitive imaging modalities due to rapid deterioration of patient’s clinical status. Abstract P242 Figure.

Neonatal Non-compacted Cardiomyopathy: Predictors of Poor Outcome.

Non-compacted cardiomyopathy (NCM) is a heterogenous myocardial disorder. Although much has been published in recent years, little is known about NCM in the neonatal period. The objective of this study is to characterize the involvement of newborns affected with NCM and to identify risk factors associated with increased mortality. This is a retrospective study including all neonates diagnosed with NCM between 2006 and 2018. Diagnosis was based on echocardiographic findings. Data were collected regarding prenatal history, gestational age and weight at birth, gender, age at diagnosis, left or biventricular involvement and associated malformations, medical and surgical treatments, and evolution. Fourteen patients were included. The median follow-up duration was 34months (range 1-87months). The left ventricular apex and lateral wall were involved in all cases (100%). Thirteen patients (92.8%) had other associated heart malformations. Six patients (42.8%) died during the follow-up period. Patients who had biventricular involvement and poor ventricular function presented a higher risk of death. The main cause of death was ventricular dysfunction (5/6 [83.3%]). During follow-up, eight patients (57.1%) underwent surgery for their cardiac malformations, without higher mortality. NCM must be included in the differential diagnosis of neonatal cardiomyopathy. The higher mortality observed in our series is related not only to the high association with congenital heart disease, but also to a greater presence of early and severe left ventricular dysfunction. We did not find that patients who underwent surgery with cardiopulmonary bypass had worse outcomes.