Both beat-to-beat changes in RR-interval and left ventricular filling time determine ventricular function during atrial fibrillation. (4th March 2021)

• Record Type: Journal Article
• Authors: Lyon, Aurore; van Mourik, Manouk; Cruts, Laura; Heijman, Jordi; Bekkers, Sebastiaan C A M; Schotten, Ulrich; Crijns, Harry J G M; Linz, Dominik; Lumens, Joost
• Is Part Of: Europace. Volume 23:Supplement 1(2021)
• Page Start: i21
• Page End: i28
• Publication Date: 2021-03-04
• Subjects: Atrial fibrillation -- Speckle-tracking echocardiography -- Left ventricular function -- Computer simulations -- Haemodynamics; Arrhythmia -- Treatment -- Periodicals; Cardiac pacing -- Periodicals; Catheter ablation -- Periodicals; Heart -- Physiology -- Periodicals; Electrophysiology -- Periodicals; 617.4120645
• DOI: 10.1093/europace/euaa387
• Languages: English
• ISSNs: 1099-5129

Abstract

Abstract: Aims: The irregular atrial electrical activity during atrial fibrillation (AF) is associated with a variable left ventricular (LV) systolic function. The mechanisms determining LV function during AF remain incompletely understood. We aimed at elucidating how changes in RR-interval and LV preload affect LV function during AF. Methods and results: Beat-to-beat speckle-tracking echocardiography was performed in 10 persistent AF patients. We evaluated the relation between longitudinal LV peak strain and preceding RR-interval during AF. We used the CircAdapt computational model to evaluate beat-to-beat preload and peak strain during AF for each patient by imposing the patient-specific RR-interval sequences and a non-contractile atrial myocardium. Generic simulations with artificial RR-interval sequences quantified the haemodynamic changes induced by sudden irregular beats. Clinical data and simulations both showed a larger sensitivity of peak strain to changes in preceding RR-interval at slow heart rate (HR) (cycle length, CL <750 ms) than at faster HR. Simulations explained this by a difference in preload of the current beat. Generic simulations confirmed a larger sensitivity of peak strain to preceding RR-interval at fast HR (CL = 600 ms: Δ peak strain = 3.7% vs. 900 ms: Δ peak strain = 0.3%) as in the patients. They suggested that longer LV activation with respect to preceding RR-interval is determinant for this sensitivity. Conclusions: During AF, longitudinal LV peak strain is highly variable, particularly at fast HR. Beat-to-beat changes in preload explain the differences in LV systolic function. Simulations revealed that a reduced diastolic LV filling time can explain the increased variability at fast HR.