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Background: Myocarditis may predispose to dilated cardiomyopathy (DCM) and sudden cardiac death (SCD). Familial data indicate a potential genetic susceptibility shared with arrhythmogenic cardiomyopathy (ACM). We present the first large-scale genotype-phenotype study of adults with acute myocarditis. Methods: A cohort comprising 336 consecutive patients with acute myocarditis was enrolled in London and Maastricht. All participants underwent targeted DNA sequencing for well-characterised cardiomyopathy-associated genes. The burden of rare protein altering variants (PAV) in ACM genes, DCM genes, and TTN specifically, were compared with local healthy controls sequenced on the same platform (n=1053). Case ascertainment was assessed against national hospital admission data. Results: We identified rare protein-altering variants in 23% of cases compared to 16% in controls (Δ+6.8%; p=0.021), with rare truncating variants (tv) in 6% of cases compared to Conclusion: We identified enrichment of cardiomyopathy gene variants in acute myocarditis patients, dominated by DSP-tv in those with normal LVEF and TTN-tv in those with reduced LVEF. Incorporation of genetic testing may be beneficial to identify such high-risk individuals and guide family screening in acute myocarditis patients.

Background Short-term sequelae of Multisystem Inflammatory Syndrome in Children (MIS-C), recently published by our institution, showed rapid improvement of the cardiac abnormalities within a few weeks after the onset of the disease. However, subtle residual abnormalities, affecting mainly the myocardial interstitium, were shown in some of the patients. The current study aimed to assess myocardial deformation with CMR shortly after MIS-C. Methods Sixty children were included into the study; 30 following MIS-C (onset-to-scan mean 27 days, SD 11) and 30 controls. Strain values were compared between patients and controls and additionally to published paediatric normal CMR values. U-Mann Whitney test was used for comparison of the myocardial deformation between patients and controls. Results Median age of the patients was 9.0 years (range 0.99–14.4) and controls 9.8 years (range 4.7–14.9). All conventional CMR parameters in patients were in normal range. Strain values were significantly lower in patients than in controls. When compared to published centile graphs, radial and circumferential global strain was within 2.5th and 97.5th centile in all patients. Eleven patients had global longitudinal strain between 2.5th centile and 50th centile, 1 patient was below 2.5th centile and all the others above 50th centile. Only 3 controls had global longitudinal strain between 2.5th centile and 50th centile, all other had higher strain. Conclusions This study demonstrates that myocardial deformation indices measured by CMR are within normal range in the vast majority of the patients within a few weeks after the onset of MIS-C. However, when compared to healthy controls, all strain parameters were lower in patients.

Objective: Myocardial first-pass perfusion imaging with MRI is well-established clinically. However, it is potentially weakened by limited myocardial coverage compared to nuclear medicine. Clinical evaluations of whole-heart MRI perfusion by 3D methods, while promising, have to date had the limit of breathhold requirements at stress. This work aims to develop a new free-breathing 3D myocardial perfusion method, and to test its performance in a small patient population. Methods: This work required tolerance to respiratory motion for stress investigations, and therefore employed a “stack-of-stars” hybrid Cartesian-radial MRI acquisition method. The MRI sequence was highly optimised for rapid acquisition and combined with a compressed sensing reconstruction. Stress and rest datasets were acquired in four healthy volunteers, and in six patients with coronary artery disease (CAD), which were compared against clinical reference information.Results: This free-breathing method produced datasets that appeared consistent with clinical reference data in detecting moderate-to-strong induced perfusion abnormalities. However, the majority of the mild defects identified clinically were not detected by the method, potentially due to the presence of transient myocardial artefacts present in the images. Discussion: The feasibility of detecting CAD using this 3D first-pass perfusion sequence during free-breathing is demonstrated. Good agreement on typical moderate-to-strong CAD cases is promising, however, questions still remain on the sensitivity of the technique to milder cases.

Introduction: Children with paediatric inflammatory multisystem syndrome temporally associated with SARS CoV2 infection (PIMS-TS) present with evidence of multiorgan dysfunction. Cardiac features include partial or typical Kawasaki disease symptoms or ventricular impairment. The aim of this study was to assess short term sequelae of cardiac involvement in patients with PIMS-TS. Methods: 17 consecutive paediatric patients with PIMS-TS were referred for CMR at our institution. The referring criteria were: Echocardiographic finding of LV dysfunction at presentation (53%), dilated coronary arteries (27%) and high cardiac markers without LV dysfunction (20%). 16 patients completed the scan and were included into the analysis. Results: Age of the patients was 17 months-12 years (mean 6.4 years), 12 (80%) were male. Six (40%) patients required general anaesthesia. The time between the onset of the symptoms and the scan was 12-72 days. All patients had SARS CoV2 PCR negative at the time of scan, 2 patients were previously positive and 12 (80%) had positive IgG. CMR indexed volumes (ml/m2) were in normal range: LVEDV 65±11, LVESV 24±7, RVEDV 67±12, RVESV 27±7. LV mass index were normal 45±8 gr/m2. No overt areas of myocardial oedema or acute inflammation on STIR (short tau inversion recovery) images were found. Mildly reduced LV ejection fraction was found in 1 patient with subtle linear late gadolinium enhancement (LGE) in the midventricular midmyocardial interventricular septum with negative STIR images. Another patient was found to have LGE of the proximal parts of mitral valve papillary muscles, but no abnormalities in the LV ejection fraction or mitral valve function were found. Two patients had a small pericardial effusion. 3 patients had dilated neck and/or innominate veins, 2 of them with phlebectatic appearance. One patient had enlarged liver, another liver and spleen. Conclusion: in conclusion no significant myocardial sequelae have been found in most of the patients presenting with PIMS-TS short-term after onset of symptoms. This might indicate rapid recovery of the cardiac inflammation in most of the patients. More follow up is needed to clarify if there will be any potential sequelae from the acute episode as well as the outcome of phlebectasia.

Background Diffusion Tensor Cardiovascular Magnetic Resonance (DT-CMR) can quantify metrics of tissue integrity (mean diffusivity [MD] and fractional anisotropy [FA]) and changes in laminar microstructures (sheetlets), which reorientate from more wall-parallel in diastole (DIA) towards wall-perpendicular in systole (SYS) as the myocardium thickens, quantified by E2 angle [E2A]. Microstructural changes after STEMI may provide new insights into adverse LV remodelling and risk stratification. Methods In vivo DT-CMR was performed 3–5 days after PPCI for first presentation STEMI (N=19, mean age 57±9, 79% male). DT-CMR was acquired in 2 short-axes (SYS & DIA) using a STEAM-EPI sequence. 12 segment analysis of MD, FA, E2A and E2A mobility (ΔE2A = E2ASYS − E2ADIA) was performed. Infarct (INF) segments were defined as >25% LGE, adjacent (ADJ, located contiguous to INF) and remote (REM, all other segments). Wilcoxon signed rank tests were used with threshold P Results See Table. MD in both SYS and DIA was significantly higher in INF and ADJ regions compared to REM. FA in both SYS and DIA was lower in the INF and ADJ compared to REM. E2ADIA was higher in INF, indicating a more wall-perpendicular orientation of sheetlets, compared to ADJ and REM zones. E2ASYS in INF was significantly reduced, indicating a more wall-parallel orientation of sheetlets, compared to ADJ and REM regions, resulting in significantly reduced sheetlet mobility (ΔE2A). Conclusions Microstructural changes can be detected after acute STEMI by in vivo DT-CMR. Zonal changes in MD and FA may suggest loss of barriers to water diffusion and altered cardiomyocyte organisation, respectively. We provide the first report of reduced sheetlet mobility after acute STEMI in INF. Ongoing work is evaluating the mechanisms and prognostic importance of altered sheetlet mobility after STEMI. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): British Heart Foundation Clinical Research Training Fellowship

Background Pediatric patients are becoming increasingly referred for cardiovascular magnetic resonance (CMR). Measurement of ventricular wall thickness is typically part of the assessment and can be of diagnostic importance, e.g. in arterial hypertension. However, normal values for left ventricular (LV) and right ventricular (RV) wall thickness in pediatric patients are lacking. The aim of this study was to establish pediatric centile charts for segmental LV and RV myocardial thickness in a retrospective multicenter CMR study. Methods CMR was performed in 161 healthy children and adolescents with an age range between 6 and 18 years from two centers in the UK and Germany as well as from a previously published CMR project of the German Competence Network for Congenital Heart Defects. LV myocardial thickness of 16 segments was measured on the short axis stack using the American Heart Association segmentation model. In addition, the thickness of the RV inferior and anterior free wall as well as biventricular mass was measured. Results The mean age (standard deviation) of the subjects was 13.6 (2.9) years, 64 (39.7%) were female. Myocardial thickness of the basal septum (basal antero- and inferoseptal wall) was 5.2 (1.1) mm, and the basal lateral wall (basal antero- and inferolateral) measured 5.1 (1.2) mm. Mid-ventricular septum (antero- and inferoseptal wall) measured 5.5 (1.2) mm, and mid-ventricular lateral wall (antero- and inferolateral wall) was 4.7 (1.2) mm. Separate centile charts for boys and girls for all myocardial segments and myocardial mass were created because gender was significantly correlated with LV myocardial thickness (p Conclusion We established CMR normal values of segmental myocardial thickness and biventricular mass in children and adolescents. Our data are of use for the detection of abnormal myocardial properties and can serve as a reference in future studies and clinical practice.

Introduction Diffusion Tensor Cardiovascular Magnetic Resonance (DT-CMR) assesses myocardial microstructure in vivo, providing information on myocyte and sheetlet organisation. Dilated cardiomyopathy (DCM) patients exhibit impaired sheetlet mobility. Approximately 1/3 DCM patients recover (R-DCM), exhibiting improved left ventricular (LV) size and ejection fraction (EF). However, there has been no study of microstructural recovery in R-DCM. Methods DT-CMR was performed in 12 DCM, 12 R-DCM, and 12 control subjects. R-DCM patients had normal indexed LV size and EF. A STEAM-EPI sequence with b=150 and b=600 at 3 T was used. LV cardiomyocyte orientation (helix angle, HA), sheetlet orientation (secondary eigenvector angulation, E2A), EF and peak radial strain were calculated. The Mann-Whitney test was used for statistical analysis. Results Groups were age and sex matched. In R-DCM, median [IQR] EF at baseline was 27[13]% and current EF was 64[7]%. The EF was 33[16]% in DCM, and 66[4]% in controls. Median [IQR] diastolic E2A in R-DCM was 25[9]°, similar to DCM (19[11]°, p=0.11) and controls (20[14]° p=0.24). However, systolic E2A in R-DCM was 59[14]°, significantly greater than DCM (35[17]° (p Conclusion Despite normal LV size and EF, R-DCM patients have persistent microstructural abnormalities. Sheetlet mobility may offer a role in disease monitoring and assessment of recovery.

Diffusion tensor cardiovascular magnetic resonance (DT-CMR) evaluates myocardial microstructure, using helix angle (HA) and absolute angulation of the second eigenvector (E2A) to assess cardiomyocyte and sheetlet orientation respectively. In health, sheetlets align more wall-parallel in diastole and

Traumatic coronary artery dissection is a very rare cause of myocardial infarction. Occurrence of this condition late in the posttraumatic period is extremely uncommon. We present a case of a young patient with acute myocardial infarction 4 weeks after blunt chest trauma. Coronary angiography showed left anterior descending artery dissection as well as thrombus formation, and multiple small infarctions were shown by cardiovascular magnetic resonance.

T2* magnetic resonance of tissue iron concentration has improved the outcome of transfusion dependant anaemia patients. Clinical evaluation is performed at 1.5 T but scanners operating at 3 T are increasing in numbers. There is a paucity of data on the relative merits of iron quantification at 3 T vs 1.5 T. A total of 104 transfusion dependent anaemia patients and 20 normal volunteers were prospectively recruited to undergo cardiac and liver T2* assessment at both 1.5 T and 3 T. Intra-observer, inter-observer and inter-study reproducibility analysis were performed on 20 randomly selected patients for cardiac and liver T2*. Association between heart and liver T2* at 1.5 T and 3 T was non-linear with good fit (R 2 = 0.954, p

BACKGROUND: There is a need for improved worldwide access to tissue iron quantification using T2* cardiovascular magnetic resonance (CMR). One route to facilitate this would be simple in-line T2* analysis widely available on MR scanners. We therefore compared our clinically validated and established T2* method at Royal Brompton Hospital (RBH T2*) against a novel work-in-progress (WIP) sequence with in-line T2* measurement from Siemens (WIP T2*). METHODS: Healthy volunteers (n = 22) and patients with iron overload (n = 78) were recruited (53 males, median age 34 years). A 1.5 T study (Magnetom Avanto, Siemens) was performed on all subjects. The same mid-ventricular short axis cardiac slice and transaxial slice through the liver were used to acquire both RBH T2* images and WIP T2* maps for each participant. Cardiac white blood (WB) and black blood (BB) sequences were acquired. Intraobserver, interobserver and interstudy reproducibility were measured on the same data from a subset of 20 participants. RESULTS: Liver T2* values ranged from 0.8 to 35.7 ms (median 5.1 ms) and cardiac T2* values from 6.0 to 52.3 ms (median 31 ms). The coefficient of variance (CoV) values for direct comparison of T2* values by RBH and WIP were 6.1-7.8 % across techniques. Accurate delineation of the septum was difficult on some WIP T2* maps due to artefacts. The inability to manually correct for noise by truncation of erroneous later echo times led to some overestimation of T2* using WIP T2* compared with the RBH T2*. Reproducibility CoV results for RBH T2* ranged from 1.5 to 5.7 % which were better than the reproducibility of WIP T2* values of 4.1-16.6 %. CONCLUSIONS: Iron estimation using the T2* CMR sequence in combination with Siemens' in-line data processing is generally satisfactory and may help facilitate global access to tissue iron assessment. The current automated T2* map technique is less good for tissue iron assessment with noisy data at low T2* values.

BACKGROUND: Myocardial black blood (BB) T2* relaxometry at 1.5T provides robust, reproducible and calibrated non-invasive assessment of cardiac iron burden. In vitro data has shown that like T2*, novel native Modified Look-Locker Inversion recovery (MOLLI) T1 shortens with increasing tissue iron. The relative merits of T1 and T2* are largely unexplored. We compared the established 1.5T BB T2* technique against native T1 values at 1.5T and 3T in iron overload patients and in normal volunteers. METHODS: A total of 73 subjects (42 male) were recruited, comprising 20 healthy volunteers (controls) and 53 patients (thalassemia major 22, sickle cell disease 9, hereditary hemochromatosis 9, other iron overload conditions 13). Single mid-ventricular short axis slices were acquired for BB T2* at 1.5T and MOLLI T1 quantification at 1.5T and 3T. RESULTS: In healthy volunteers, median T1 was 1014 ms (full range 939-1059 ms) at 1.5T and modestly increased to 1165ms (full range 1056-1224 ms) at 3T. All patients with significant cardiac iron overload (1.5T T2* values

Background Atrial fibrillation (AF) is the commonest sustained arrhythmia afflicting the adult population. Identifying and ablating triggers in the left atrium (LA) or more often the pulmonary veins (PV) with radiofrequency energy to restore sinus rhythm is fast becoming the mainstay of treatment. The success of the procedure often requires a combination of imaging techniques with an electroanatomical mapping system. We describe the use of three dimensional (3D) delayed enhancement cardiovascular magnetic resonance imaging (DE-MRI) to provide a road map of the anatomy as well as regions of scar tissues in the LA and PV for AF ablation. Methods

Methods Twenty one body-builders were studied 14 anabolic steroid users and 7 controls matched for age and training history. First pass CMR perfusion imaging was performed on a 1.5T Avanto (Siemens, Erlangen, Germany) after adenosine-induced hyperemia (140 mcg/kg/min) and at rest using a hybrid echo-planar imaging sequence. Images of the base, mid-ventricle and apex were acquired and the myocardium was divided into 16 segments as well as endocardial and epicardial layers. After image registration, a modified Fermi-constrained deconvolution algorithm was applied pixel-wise to quantify absolute MBF. Late gadolinium enhancement (LGE) imaging was performed as well as standard assessment of ventricular volumes, function and LV mass. Data were analysed using a linear mixed effects model.

Non-invasive assessment of interstitial myocardial fibrosis in pressure-overload left ventricular hypertrophy Andrew Jabbour, Tevfik F Ismail, Sofia V De Noronha, Carl Shakespeare, Sameer Zaman, Oluwatosin Sotubo, Saman S Zaman, Callum Ettles, Benjamin Hewins, Rick Wage, Ankur Gulati, Pedro F Ferreira, Pierre Croisille, Yanqiu Feng, Katsuya Norita, Raad H Mohiaddin, Taigang He, John Pepper, David N Firmin, Mary Sheppard, Dudley J Pennell, Mario Petrou, Sanjay K Prasad

Background There has been considerable interest in high resolution 3D late gadolinium enhancement (LGE) imaging in the atrial fibrillation (AF) population, both pre and post RF ablation. Unlike conventional studies, these are performed with single R-wave gating to reduce the acquisition duration and the effects of gadolinium wash-out. For AF, the heart rate variability results in variable magnetization recovery between sequence repeats which, with a fixed inversion time (TI), causes ghosting and poor nulling of normal tissue. This is exacerbated by missed triggers and the number of poor quality studies is high. An adaptive inversion recovery preparation has previously been demonstrated in a 2D phantom acquisition [1]. The purpose of this study is to implement such a technique (dynamic_TI) for improved imaging in the AF population.

Background Hypertrophic cardiomyopathy (HCM) is associated with increased myocardial fibrosis and collagen deposition. Collagen reduces cardiovascular magnetic resonance (CMR) derived T2 times, however, the inflammatory milieu required for its deposition is often associated with localised oedema. Focal areas of high T2 signal intensity have been reported in association with areas of late gadolinium enhancement (LGE) in patients with HCM. However, this previous work has relied upon the subjective visual assessment of local changes in signal intensity. We hypothesised that quantitative CMR T2mapping would reveal marked differences in myocardial T2 characteristics in patients with HCM relative to controls. Methods Twenty-two consecutive patients with HCM (15 male, age 55.8±8.7 years) but no co-morbidity and 22 healthy controls (9 male, age 49.3±13.1 years) were studied. For each subject, a short axis mid-ventricular slice was acquired using a 1.5T Avanto (Siemens Healthcare, Erlangen, Germany). A breath-hold T2-prepared singleshot steady-state free precession (SSFP) sequence was used to produce three T2-weighted images with different T2 preparation times (0 ms, 24 ms, 55 ms). Parallel imaging was used to reduce the imaging time and motioncorrection was applied to improve the accuracy of T2 measurement. T2 maps were produced by fitting the signal intensity-time exponential decay curve using a linear 2-parameter model after logarithmic transformation (CMRtools, Cardiovascular Imaging Solutions, London, UK). An inversion recovery prepared gradient echo sequence with the inversion time optimised to null normal myocardium was used 10 minutes after intravenous gadolinium contrast (Gadovist, Bayer-Schering, Berlin, Germany, 0.1 mmol/kg) to detect late enhancement. Imaging was repeated in an orthogonal phase encoding direction to exclude artifact. Results There were no significant differences in baseline demographic characteristics between HCM and control patients. LV-wall thickness, indexed LV mass and ejection fraction were significantly higher in HCM patients (Table 1). In keeping with LV hypertrophy, the LV volumes were significantly smaller. None of the healthy controls exhibited any late enhancement whereas 18 (82%) HCM patients had areas of mid-wall enhancement, predominantly in the areas of hypertrophy. T2 times in patients with HCM were similar to controls with no evidence of any significant differences (HCM 54.1±2.5ms versus Controls 54.1±1.6ms, P=0.97). Conclusions

Background Abuse of anabolic steroids to induce skeletal muscle hypertrophy is widespread amongst recreational bodybuilders, however, the cardiac effects of such drugs have not been systematically documented. The ability of cardiovascular magnetic resonance (CMR) to image the myocardium in any plane and achieve full myocardial coverage renders it the gold standard for assessing LV volumes and mass.We sought to investigate the cardiac effects of anabolic steroid use with CMR hypothesising that significant hypertrophy and distinct LV remodelling would be seen in steroid users relative to non-users. Methods

Objectives The goal of this study was to assess the prognostic significance of midwall and infarct patterns of late gadolinium enhancement (LGE) in aortic stenosis. Background Myocardial fibrosis occurs in aortic stenosis as part of the hypertrophic response. It can be detected by LGE, which is associated with an adverse prognosis in a range of other cardiac conditions. Methods Between January 2003 and October 2008, consecutive patients with moderate or severe aortic stenosis undergoing cardiovascular magnetic resonance with administration of gadolinium contrast were enrolled into a registry. Patients were categorized into absent, midwall, or infarct patterns of LGE by blinded independent observers. Patient follow-up was completed using patient questionnaires, source record data, and the National Strategic Tracing Service. Results A total of 143 patients (age 68 ± 14 years; 97 male) were followed up for 2.0 ± 1.4 years. Seventy-two underwent aortic valve replacement, and 27 died (24 cardiac, 3 sudden cardiac deaths). Compared with those with no LGE (n = 49), univariate analysis revealed that patients with midwall fibrosis (n = 54) had an 8-fold increase in all-cause mortality despite similar aortic stenosis severity and coronary artery disease burden. Patients with an infarct pattern (n = 40) had a 6-fold increase. Midwall fibrosis (hazard ratio: 5.35; 95% confidence interval: 1.16 to 24.56; p = 0.03) and ejection fraction (hazard ratio: 0.96; 95% confidence interval: 0.94 to 0.99; p = 0.01) were independent predictors of all-cause mortality by multivariate analysis. Conclusions Midwall fibrosis was an independent predictor of mortality in patients with moderate and severe aortic stenosis. It has incremental prognostic value to ejection fraction and may provide a useful method of risk stratification. (The Prognostic Significance of Fibrosis Detection in Cardiomyopathy; NCT00930735)

Introduction In patients undergoing percutaneous coronary intervention (PCI), 15 to 26% develop elevated creatine kinase isoenzyme MB (CKMB) levels after the procedure. Troponin rise is even more frequent and is observed in 29– 48% of patients in a standard daily practice procedure. Little is known about the mechanism of this damage specifically in patient with complex PCI. Cardiovascular Magnetic Resonance (CMR) with gadolinium-based contrast media administration can non-invasively detect myocardial fibrosis. Inversion recovery preparation with segmented gradient echo readout (GRE) using recovery sequences is considered the gold standard sequence for the detection of late gadolinium myocardial enhancement (LGE).

Methods Sixteen consecutive patients with CTO were recruited in the study and 12 patients underwent a CMR MPI both before (6.3 ± 6.4 days) and after revascularization (56 ± 39 days). CMR MPI study was performed in 1.5 T Siemens Avanto scanner using a 3 slice hybrid-EPI sequence with TSENSE. First-pass stress perfusion imaging was performed after 4 minutes of 140 μg/kg/min adenosine and 0.1 mmol/Kg of Gd-DTPA injected at 7 ml/s, followed by late enhancement imaging with inversion-recovery segmented FLASH sequence. First-pass rest perfusion images were acquired > 20 minutes after stress perfusion imaging. In addition, we obtained multiple SSFP cine images to encompass the left ventricle from base to apex (8 mm slice thickness, 2 mm gap). A visual wall motion, gadolinium and perfusion score (0–4) on a 16-segment model was applied and myocardial perfusion reserve index (MPRI) was calculated in all CTO myocardial territories. Left ventricular end-diastolic (LVDV) and end-systolic volumes (LVSV), ejection fraction (LVEF) and infarcted mass were also calculated.

Background Interstitial myocardial fibrosis is a histological hallmark of non-ischemic dilated cardiomyopathy (DCM), and may play an important role in adverse remodelling and progressive systolic dysfunction. T1-mapping enables noninvasive assessment of diffuse fibrosis by quantification of myocardial extracellular volume fraction (ECV). We hypothesized that CMR would identify a raised ECV in DCM which would correlate with the degree of systolic dysfunction.

Background Fibrosis is thought to play an important role in the pathogenesis of the adverse sequelae of hypertrophic cardiomyopathy (HCM). Late gadolinium enhancement (LGE) cardiovascular magnetic resonance detects replacement fibrosis but cannot presently detect interstitial fibrosis. The latter is thought to be a very early feature of HCM and can be triggered by inflammation, which can also expand the size of the myocardial interstitium. We sought to determine whether extracellular volume (ECV) mapping by T1-relaxometry in concert with T2mapping can identify interstitial changes in HCM and whether these were related to myocardial edema.

Methods A Siemens scanner (Avanto, 1.5T) was used to study 13 patients (mean age 65 ± 9, 4 females and 9 males) with persistent AF before and 3 months after ablation therapy. Images of the LA were acquired in the two-chamber and four-chamber orientation using a breath-hold ECG-gated steady state free precession cine sequence. Biplane arealength method was used to measure the LA end-systolic (ESV) and end-diastolic (EDV) volumes[1]. LA function was determined by its calculated ejection fraction (EF=(EDV-ESV)/EDV) [1]. Seven-day rhythm tape was used to assess patients’ rhythm 3 months after ablation. All 13 patients underwent either surgical or catheter ablation therapy successfully, achieving sinus rhythm post procedure. Only 2 patients reverted to AF at 3 months.

circumferential max strain (r=0.43, p=0.03), angle δ strain (r=0.78, p=0.001), and motion magnitude peak strain (r=0.87, p

Background Interstitial fibrosis is a pathological hallmark of hypertrophic cardiomyopathy (HCM) and is thought to contribute to the abnormal myocardial mechanics seen in this patient group. T1-mapping now allows interstitial fibrosis to be detected non-invasively. Replacement fibrosis as identified by late gadolinium enhancement imaging has been associated with abnormal cardiac mechanics in HCM. However, the relationship between interstitial fibrosis and contractile function in HCM has not been previously explored. We assessed the association between interstitial fibrosis as assessed by T1-mapping and contractile function as determined by continuous spatial modulation of magnetisation (CSPAMM) tagging, hypothesising that increased fibrosis would correlate with abnormal myocardial strain. Methods Twelve HCM patients free of significant comorbidity and 16 controls were studied. CMR was undertaken on a 1.5T Siemens Avanto (Siemens, Erlangen, Germany). Tagged images were acquired at the mid-ventricle using aC SPAMM sequence (Field of View: 300mm, slice thickness 6mm, tag separation 7mm, typical TR/TE 30/ 1.26ms, Flip Angle 20°, 20 phases). Peak circumferential (Ecc) and radial (Err) strains were determined using inTag (Creatis, Lyon, France). Mid-ventricular short-axis T1 maps were acquired using the Modified Look-Locker Inversion Recovery sequence pre-gadolinium bolus and then at 5, 7, 9, 11, 15, 20 and 25 minutes. Signal intensity-time curves for myocardial and blood pool regions of interest were used to determine T1 relaxation times through a non-linear curve-fit (CMR42, Circle Cardiovascular Imaging, Calgary, Canada). The partition coefficient at equilibrium, an index of fibrosis, was determined by plotting the reciprocal of myocardial T1 times at equilibrium against those for the blood pool and calculating the slope of the resultant linear regression line. Results HCM patients were older than the controls and there was a preponderance of men. In keeping with their diagnosis, HCM patients had significantly higher indexed LV mass and wall thickness than controls (Table 1). The partition coefficient was significantly higher in HCM patients than controls (mean ±SD: 0.439 ±0.230 for HCM vs 0.281 ±0.071 for controls, P=0.02). Whilst peak global Ecc was significantly lower in the HCM group relative to the controls (0.173 ±0.041 vs 0.226 ±0.025, P