Ventricular rate and regularity affect hemodynamic stability and are targets of rate control therapy in @entity1 with @entity956 ( @entity956 ) and @entity955 ( @entity955 ). Nevertheless the characteristics and determinants of ventricular response during these @entity943 are poorly understood. This work aims to investigate the effects of changes in atrial activity and atrioventricular (AV) conduction patterns on ventricular response in @entity1 with @entity4710 by a combined quantitative analysis of atrial and ventricular time series. Time series were determined in @entity1 during 24 episodes of @entity956 and 13 episodes of @entity955 . Ventricular response was characterized in terms of mean ventricular interval, time-domain variability parameters, and entropy-based irregularity measures (quadratic entropy rate, QSE, and coefficient of sample entropy, COSEn). Atrial activity was characterized in terms of mean atrial rate and variability. AV conduction was analyzed by AV synchrogram method, quantifying the stability of AV coupling and the average AV conduction ratio. The dependence of ventricular features on @entity713 was investigated by correlation analysis. The analysis showed ventricular response to display a wide spectrum of variability and irregularity features at changing atrial and AV properties. The ventricular interval was significantly correlated with the AV conduction ratio (Spearman correlation coefficient   =-0.76, p<0.005), while it did not correlate with atrial rate. The variability and irregularity of ventricular response were influenced by both @entity713 . QSE and COSEn significantly increased at shorter atrial cycle lengths (  =-0.67 and -0.71, p<0.005), at higher atrial variability (  =0.80 and 0.77, p<0.005), at reduced AV coupling (  =-0.91, p<0.005) and at smaller AV conduction ratios (  =-0.65 and -0.52, p<0.005). The identification of the determinants of ventricular rate and regularity may have significant implications in the development of efficacious rate control strategies in @entity1 with @entity4710 .

Characterization of rate and regularity of ventricular response during @entity4710 . Insight on XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity713 :: ('MESH:D054537', 'Disease') :: ['atrial/AV determinants', 'atrial and AV parameters'] @entity956 :: ('MESH:D001282', 'Disease') :: ['atrial flutter', 'AFL'] @entity955 :: ('MESH:D001281', 'Disease') :: ['atrial fibrillation', 'AF'] @entity4710 :: ('MESH:D013617', 'Disease') :: ['atrial tachyarrhythmias'] @entity943 :: ('MESH:D001145', 'Disease') :: ['atrial arrhythmias']
@entity955 :: (MESH:D001281,Disease) :: ['atrial and nodal determinants']
