The objective of this study was to compare the baroreflex sensitivity (BRS) assessed by the new, non-invasive, spontaneous sequence method (BRS-sequence) with the Valsalva manoeuvrebased BRS. Fourteen healthy volunteers were studied in the supine position, during 60 degrees head-up tilt (HUT) and during -30 degrees head-down tilt (HDT). Blood pressure and R-R intervals were continuously and non-invasively recorded using a Finapres device. The BRS-sequence was assessed by analysing the slopes of spontaneously occurring sequences of three or more consecutive beats in which systolic blood pressure and R-R interval of the following beat increased or decreased in the same direction in a linear fashion; it was compared with data obtained during the Valsalva manoeuvre in each position. The time and frequency domain indices of R-R interval variability were also evaluated. The mean difference of BRS between the two non-invasive methods was 3.86 ms/mmHg with a standard deviation of 9.14 ms/mmHg. BRS was decreased during HUT and increased during HDT as assessed by both techniques. The changes in BRS were associated with vagal withdrawal and sympathetic activation during HUT and enhancement in the cardiac vagal tone and reduction in the sympathetic activity during HDT. We conclude that the BRS-sequence technique provides a reliable method to study the neural control of the circulation, although the body position in consecutive measurements needs to be standardized.

Background - Atrial fibrillation (AF) recurrence following catheter ablation remains high. Recent studies have shown a relation between epicardial adipose tissue (EAT) and AF. EAT secretes several pro- and anti-inflammatory adipokines that directly interact with the adjacent myocardium. The aim of the current study was to evaluate whether posterior left atrial (LA) adipose tissue attenuation, as marker of inflammation, is related to AF recurrences after catheter ablation. Methods - Consecutive patients with symptomatic AF referred for first AF catheter ablation who underwent CT were included. The total EAT and posterior LA adipose tissue were manually traced and adipose tissue was automatically recognized as tissue with Hounsfield units (HU) between -195 and -45. The attenuation value of the posterior LA adipose tissue was assessed and the population divided according to the mean HU value (-96.4 HU). Results - In total, 460 patients (66% male, age 61 ± 10 years) were included in the analysis. After a median follow-up of 18 months (IQR 6-32), 168 (37%) patients had AF recurrence. Patients with higher attenuation (≥-96.4 HU) of the posterior LA adipose tissue showed higher AF recurrence rates compared to patients with lower attenuation (<-96.4 HU) (log-rank test p=0.046). Univariate analysis showed an association between AF recurrence and higher posterior LA adipose tissue attenuation (≥-96.4 HU) (p<0.05). On multivariable analysis posterior LA adipose tissue attenuation (HR 1.26; 95% CI 0.90-1.76; p=0.181) remained a promising predictor of AF recurrence following catheter ablation. Conclusions - Posterior LA adipose tissue attenuation is a promising predictor of AF recurrence in patients who undergo catheter ablation. Higher adipose tissue attenuation might signal increased local inflammation and serve as an imaging biomarker of increased risk of AF recurrence.

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IntroductionThe role of the spatial relationship between the left superior pulmonary vein (LSPV) and left atrial appendage (LAA) is unknown. We sought to evaluate whether an abutting LAA and LSPV play a role in AF recurrence after catheter ablation for paroxysmal AF.MethodsConsecutive patients, who underwent initial point-by-point radiofrequency catheter ablation for paroxysmal AF at the Heart and Vascular Center of Semmelweis University, Budapest, Hungary, between January of 2014 and December of 2017, were enrolled in the study. All patients underwent pre-procedural cardiac CT to assess left atrial (LA) and pulmonary vein (PV) anatomy. Abutting LAA-LSPV was defined as cases when the minimum distance between the LSPV and LAA was less than 2 mm.ResultsWe included 428 patients (60.7 ± 10.8 years, 35.5% female) in the analysis. AF recurrence rate was 33.4%, with a median recurrence-free time of 21.2 (8.8–43.0) months. In the univariable analysis, female sex (HR = 1.45; 95%CI = 1.04–2.01; p = 0.028), LAA flow velocity (HR = 1.01; 95%CI = 1.00–1.02; p = 0.022), LAA orifice area (HR = 1.00; 95%CI = 1.00–1.00; p = 0.028) and abutting LAA-LSPV (HR = 1.53; 95%CI = 1.09–2.14; p = 0.013) were associated with AF recurrence. In the multivariable analysis, abutting LAA-LSPV (adjusted HR = 1.55; 95%CI = 1.04–2.31; p = 0.030) was the only independent predictor of AF recurrence.ConclusionAbutting LAA-LSPV predisposes patients to have a higher chance for arrhythmia recurrence after catheter ablation for paroxysmal AF.

Background: Quantitative coronary plaque parameters are increasingly being utilized as surrogate endpoints of pharmaceutical trials. However, little is known whether differences in segmentation significantly alter parameter values. Methods: Overall, 100 coronary plaques with adverse imaging characteristics were segmented automatically, by two experts (R 1-R 2) and three nonexperts (R 3-R 5). Low attenuation noncalcified (LANCP), noncalcified and calcified plaque volume were calculated and 4310 radiomic features were extracted. Intraclass correlation coefficient (ICC) values were calculated between the segmentations. Results: ICC values between expert readers were 0.84 [