Direction- and rate-dependent fractionation during atrial fibrillation persistence: Unmasking cardiac anisotropy?

This human case is the first to illustrate morphological manifestations of direction- and rate-dependent anisotropic conduction in high-resolution unipolar atrial potentials. Premature impulses induced low-amplitude, fractionated extracellular potentials with exceptionally prolonged durations in a 76-year old longstanding persistent patient with atrial fibrillation (AF), demonstrating direction-dependency of anisotropic conduction. An increased pacing frequency induced presence of similar fractionated potentials, reflecting rate-dependent anisotropy and inhomogeneous, slow conduction. Pacing with different rates and from different sites could aid in identifying nonuniform anisotropic tissue and thus the substrate of AF

The Impact of Filter Settings on Morphology of Unipolar Fibrillation Potentials

Using unipolar atrial electrogram morphology as guidance for ablative therapy is regaining interest. Although standardly used in clinical practice during ablative therapy, the impact of filter settings on morphology of unipolar AF potentials is unknown. Thirty different filters were applied to 2,557,045 high-resolution epicardial AF potentials recorded from ten patients. Deflections with slope ≤ − 0.05 mV/ms and amplitude ≥ 0.3 mV were marked. High-pass filtering decreased the number of detected potentials, deflection amplitude, and percentage of fractionated potentials (≥ 2 deflections) as well as fractionation delay time (FDT) and increased percentage of single potentials. Low-pass filtering decreased the number of potentials, percentage of fractionated potentials, whereas deflection amplitude, percentage of single potentials, and FDT increased. Notch filtering (50 Hz) decreased the number of potentials and deflection amplitude, whereas the percentage of complex fractionated potentials (≥ 3 deflections) increased. Filtering significantly impacted morphology of unipolar fibrillation potentials, becoming a potential source of error in identification of ablative targets.

Atrial fibrillation fingerprinting; spotting bio-electrical markers to early recognize atrial fibrillation by the use of a bottom-up approach (AFFIP): Rationale and design

Background: The exact pathophysiology of atrial fibrillation (AF) remains incompletely understood and treatment of AF is associated with high recurrence rates. Persistence of AF is rooted in the presence of electropathology, defined as complex electrical conduction disorders caused by structural damage of atrial tissue. The atrial fibrillation fingerprinting (AFFIP) study aims to characterize electropathology, enabling development of a novel diagnostic instrument to predict AF onset and early progression. Hypotheses: History of AF, development of post-operative AF, age, gender, underlying heart disease, and other clinical characteristics impact the degree of electropathology. Methods: This study is a prospective observational study with a planned duration of 48 months. Three study groups are defined: (1) patients with (longstanding) persistent AF, (2) patients with paroxysmal AF, and (3) patients without a history of AF, all undergoing open-chest cardiac surgery. Intra-operative high-resolution epicardial mapping is performed to identify the patient-specific electrical profile, whereas the patient-specific biological profile is assessed by evaluating proteostasis markers in blood samples and atrial appendage tissue samples. Post-operative continuous rhythm monitoring is perfo

Cancer-related Fatigue in Relation to Chronotype and Sleep Quality in (Non-)Hodgkin Lymphoma Survivors

Cancer-related fatigue has been related to circadian disruptions and lower levels of sleep quality. However, it is unknown whether the circadian phase, which is associated with chronotype and timing of sleep, is related to fatigue after cancer. The aims of this study were to investigate the associations between (1) chronotype and cancer-related fatigue and (2) sleep quality and cancer-related fatigue. In this cross-sectional questionnaire study, 458 (non-)Hodgkin lymphoma survivors (n = 231 female, mean age 49.7 years) completed a Visual Analogue Scale for fatigue (VAS-fatigue) from 0 (no fatigue) to 10 (worst imaginable fatigue), the Munich Chronotype Questionnaire (MCTQ), and the Pittsburgh Sleep Quality Index (PSQI) between October 2018 and July 2019. A hierarchical linear regression analysis was used to evaluate the associations between the dependent variable fatigue and chronotype (based on early, intermediate, or late average midsleep) in Model 1, and fatigue and sleep quality in Model 2. The results showed no indications for an association between chronotype and fatigue (all p values >= 0.50). There were associations between two (out of seven) aspects of sleep quality and fatigue: subjective sleep quality (p < 0.001) and daily dysfunctioning (p < 0.001). Therefore, it is more likely that fatigue is associated with self-reported sleep quality rather than with chronotype. However, experimental studies with objective, physiological data on circadian phase and sleep quality are necessary to confirm the conclusions of this cross-sectional study.Hereditary cancer genetic

Daily Supplementation of L-Glutamine in Atrial Fibrillation Patients: The Effect on Heat Shock Proteins and Metabolites

Pharmaco-therapeutic strategies of atrial fibrillation (AF) are moderately effective and do not prevent AF onset and progression. Therefore, there is an urgent need to develop novel therapies. Previous studies revealed heat shock protein (HSP)-inducing compounds to mitigate AF onset and progression. Such an HSP inducing compound is L-glutamine. In the current study we investigate the effect of L-glutamine supplementation on serum HSP27 and HSP70 levels and metabolite levels in patients with AF patients (n = 21). Hereto, HSP27

Classification of sinus rhythm single potential morphology in patients with mitral valve disease

Aims The morphology of unipolar single potentials (SPs) contains information on intra-atrial conduction disorders and possibly the substrate underlying atrial fibrillation (AF). This study examined the impact of AF episodes on features of SP morphology during sinus rhythm (SR) in patients with mitral valve disease. Methods and results Intraoperative epicardial mapping (interelectrode distance 2 mm) of the right and left atrium (RA, LA), Bachmann’s bundle (BB), and pulmonary vein area (PVA) was performed in 67 patients (27 male, 67 ± 11 years) with or without a history of paroxysmal AF (PAF). Unipolar SPs were classified according to their differences in relative R- and Swave amplitude ratios. A clear predominance of S-waves was observed at BB and the RA in both the no AF and PAF groups (BB 88.8% vs. 85.9%, RA 92.1% vs. 85.1%, respectively). Potential voltages at the RA, BB, and PVA were significantly lower in the PAF group (P < 0.001 for each) and were mainly determined by the size of the Swaves amplitudes. The largest difference in S-wave amplitudes was found at BB; the S-wave amplitude was lower in the PAF group [4.08 (2.45–6.13) mV vs. 2.94 (1.40–4.75) mV; P < 0.001]. In addition, conduction velocity (CV) at BB was lower as well [0.97 (0.70–1.21) m/s vs. 0.89 (0.62–1.16) m/s, P < 0.001]. Conclusion Though excitation of the atria during SR is heterogeneously disrupted, a history of AF is characterized by decreased SP amplitudes at BB due to loss of S-wave amplitudes and decreased CV. This suggests that SP morphology could provide additional information on wavefront propagation

Differential transferrin expression in placentae from normal and abnormal pregnancies: a pilot study

Abstract Background The placenta is an important site for iron metabolism in humans. It transfers iron from the mother to the fetus. One of the major iron transport proteins is transferrin, which is a blood plasma protein crucial for iron uptake. Its localization and expression may be one of the markers to distinguish placental dysfunction. Methods In the experimental study we used antibody preparation, mass spectrometric analysis, biochemical and immunocytochemical methods for characterization of transferrin expression on the human choriocarcinoma cell line JAR (JAR cells), placental lysates, and cryostat sections. Newly designed monoclonal antibody TRO-tf-01 to human transferrin was applied on human placentae from normal (n = 3) and abnormal (n = 9) pregnancies. Results Variations of transferrin expression were detected in villous syncytiotrophoblast, which is in direct contact with maternal blood. In placentae from normal pregnancies, the expression of transferrin in the syncytium was significantly lower (p Conclusion These observations suggest that in the case of abnormal pregnancies, the fetus may require higher levels of transferrin in order to prevent iron depletion due to the stress from the placental dysfunction.</p