Find Me If You Can: First Clinical Experience Using the Novel CARTOFINDER Algorithm in a Routine Workflow for Atrial Fibrillation Ablation.

AIMS: The CARTOFINDER module allows for simultaneous and automated detection of repetitive focal and rotational activations in patients with atrial arrhythmias. This study aimed to validate the CARTOFINDER algorithm for the detection of potential drivers for atrial fibrillation (AF) and to access their potential impact on individual arrhythmia substrates. METHODS: Fifty consecutive patients underwent AF ablation for persistent AF (PERS), using a 3D-mapping system with the integrated CARTOFINDER module. Regions of interest (ROIs) were identified before and after ablation, and their spatial and temporal relationship was correlated with areas of fibrosis. RESULTS: Procedural success was achieved in all patients and 42% received ablation beyond pulmonary vein isolation (PVI). AF termination was observed in 6 patients (12%). The mean procedure duration was 134 ± 29 min. ROIs were revealed in all patients (mean n = 77 ± 52) and there was no statistical evidence for a predilection site. There was no significant anatomical correlation between ROIs and bipolar low voltage. Remapping confirmed the elimination of ROIs in relation to the individual ablation site, a limited reproducibility of rotational ROIs and persistent focal activity over time in some anatomical segments. ROIs were not a predictor for AF recurrence during following ablation. CONCLUSIONS: CARTOFINDER mapping can be integrated into a routine workflow for AF ablation. ROIs could be discriminated in all patients and an ablation effect was observed in some patients, whereas persistent activity was found in certain anatomical segments, even after ablation. ROIs might be an additional ablation target when we are able to understand the individual substrate.

Impact of gender and age on cardiovascular function late after repair of tetralogy of Fallot: percentiles based on cardiac magnetic resonance.

BACKGROUND: The impact of gender and age on cardiac function by cardiac magnetic resonance (CMR) in repaired tetralogy of Fallot (TOF) is unknown, which limits the value of currently discussed volumetric thresholds and the accuracy of individual follow-up. METHODS AND RESULTS: In a nationwide, prospective, 14-center study, 407 consecutive patients with repaired TOF (age, 17.9±8.3 years; range, 8-59 years; 226 male patients) underwent standardized CMR ventricular volumetry and flow quantification (pulmonary artery/ascending aorta). There were no sex differences for age at TOF repair, type of repair, number of prior repair palliations or reinterventions after repair, pulmonary regurgitation fraction, and maximal gradient across the right ventricular outflow tract. Biventricular volumes and mass (indexed to body surface area), available in 380 of 407 patients, respectively, were higher in male patients (P<0.003), but biventricular ejection fraction was higher in female patients (P<0.012). As opposed to reported data of healthy populations, sex-specific reference percentiles computed for an age range of 8 to 40 years (lambda-mu-sigma method) demonstrated (1) an increase of end-diastolic and end-systolic left ventricular volumes, particularly in female patients; (2) an increase of end-systolic right ventricular volumes in both sexes; and (3) a decrease of biventricular ejection fraction in male patients, whereas in female patients, only right ventricular ejection fraction decreased. CONCLUSIONS: Significant gender differences of biventricular volumes, function, and mass by CMR exist late after repair of TOF, suggesting that age and gender cannot be ignored when discussing thresholds. Gender-specific percentiles may present a more relevant framework of reference for an individual patient at a given age and suggest a gradual decline of biventricular systolic function over time.

Reference values for atrial size and function in children and young adults by cardiac MR: a study of the German competence network congenital heart defects.

PURPOSE: To provide reference data for atrial size and function during childhood and adolescence by cardiac MR (CMR). MATERIALS AND METHODS: We prospectively examined 115 healthy children and adolescents (mean age, 12.4 ± 4.1 years; range, 4.4-20.3 years) by CMR using a stack of standard two-dimensional steady-state free-precession slices acquisition covering the whole heart in transverse plane. Maximal and minimal volumes of both atria and their respective calculated cyclic volume change (CVC) and emptying fraction (EMF) were determined and reference centile curves were computed (lambda-mu-sigma [LMS]-method). RESULTS: Gender differences were noted for atrial volumes and derived parameters. Maximal right atrial (RA) volume for girls was 53.3 ± 11.8 mL/m(2) and 58.1 ± 15.7 for boys (P = 0.064), minimal RA volume for girls/boys was 23.2 ± 6.2/27.0 ± 7.9 mL/m(2) (P = 0.004). Maximal left atrial (LA) volume for girls/boys was 44.2 ± 8.7/46.7 ± 10.1 mL/m(2) (P = 0.143) and minimal LA volume for girls/boys was 19.2 ± 3.9/21.5 ± 5.1 mL/m(2) (P = 0.009). For both atria, CVC was higher for boys, but EMF higher for girls. Percentiles of RA/LA volumes showed steeper increase in boys than in girls, who in fact showed a plateau after age 14. CONCLUSION: Pediatric sex-specific reference centiles are provided to improve clinical interpretation and facilitate future research involving CMR-derived atrial function.

Sex-specific pediatric percentiles for ventricular size and mass as reference values for cardiac MRI: assessment by steady-state free-precession and phase-contrast MRI flow.

BACKGROUND: Cardiac MRI is important in the treatment of children with congenital heart disease, but sufficient normative data are lacking. For ventricular volumes and mass, we sought to deliver reference centiles and to investigate sex effects. METHODS AND RESULTS: We included 114 healthy children and adolescents, uniformly distributed spanning an age range of 4 to 20 years, as required by the Lambda-Mu-Sigma method to achieve a percentile distribution, thus avoiding arbitrary age categories. Subjects underwent axial volumetry (1.5-T scanner) using standardized 2D steady-state free-precession and flow protocols. Percentiles were computed for age 8 to 20 years (99 subjects) because breath-holds were more consistent in this group. When indexed for body surface area or height, the centile curves of ventricular volumetric parameters showed allometric increase until adolescence, when a plateau was reached, with values comparable to published adult reference data. In contrast, ventricular mass centiles increased without plateau. There was a significant sex difference, with centiles reflecting larger values in boys than in girls (P<0.05) when ventricular volumes were indexed to body surface area or height but not when indexed to weight (exception: mass). There was excellent agreement of axial and short-axis volumetry and of volumetric and flow-derived stroke volumes. CONCLUSIONS: Percentiles for ventricular volumes and mass in healthy children have been established to serve as reference values in pediatric heart disease. Significant sex differences were noted when indexing volumes to body surface area or height. Unisex centiles related to weight may be considered for chamber volumes albeit not for mass.