1. Structural, Functional, and Electrical Remodeling of the Atria With Reduced Cardiorespiratory Fitness: Implications for AF.
- Author
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Ariyaratnam JP, Elliott AD, Mishima RS, Kadhim K, Emami M, Fitzgerald JL, Middeldorp M, and Sanders P
- Subjects
- Humans, Male, Female, Middle Aged, Aged, Exercise Test, Echocardiography, Catheter Ablation, Atrial Function, Left physiology, Oxygen Consumption physiology, Atrial Fibrillation physiopathology, Atrial Fibrillation surgery, Cardiorespiratory Fitness physiology, Atrial Remodeling physiology, Heart Atria physiopathology, Heart Atria diagnostic imaging
- Abstract
Background: Reduced cardiorespiratory fitness (CRF) is an independent risk factor for the progression of atrial fibrillation (AF). We hypothesized that reduced CRF is associated with structural, functional, and electrical remodeling of the left atrium., Objectives: This study sought to correlate objectively assessed CRF with functional and electrical left atrial (LA) parameters using invasive and noninvasive assessments., Methods: Consecutive patients with symptomatic AF undergoing catheter ablation were recruited. CRF was objectively quantified pre-ablation by using cardiopulmonary exercise testing. Using peak oxygen consumption, participants were classified as preserved CRF (>20 mL/kg/min) or reduced CRF (<20 mL/kg/min). LA stiffness was assessed invasively with hemodynamic monitoring and imaging during high-volume LA saline infusion. LA stiffness was calculated as ΔLA diameter/ΔLA pressure over the course of the infusion. LA function was assessed with echocardiographic measures of LA emptying fraction and LA strain. Electrical remodeling was assessed by using high-density electroanatomical maps for LA voltage and conduction., Results: In total, 100 participants were recruited; 43 had reduced CRF and 57 had preserved CRF. Patients with reduced CRF displayed elevated LA stiffness (P = 0.004), reduced LA emptying fraction (P = 0.006), and reduced LA reservoir strain (P < 0.001). Reduced CRF was also associated with reduced LA voltage (P = 0.039) with greater heterogeneity (P = 0.027) and conduction slowing (P = 0.04) with greater conduction heterogeneity (P = 0.02). On multivariable analysis, peak oxygen consumption was independently associated with LA stiffness (P = 0.003) and LA conduction velocities (P = 0.04)., Conclusions: Reduced CRF in patients with AF is independently associated with worse LA disease involving functional and electrical changes. Improving CRF may be a target for restoring LA function in AF., Competing Interests: Funding Support and Author Disclosures This study was supported by the Center for Heart Rhythm Disorders at the University of Adelaide. Drs Ariyaratnam, Mishima, Kadhim, Emami, and Fitzgerald are supported by Postgraduate Scholarships from the University of Adelaide. Dr Elliott is supported by a Future Leader Fellowship from the National Heart Foundation of Australia. Dr Sanders is supported by an Investigator Grant from the National Health and Medical Research Council of Australia. Dr Emami reports that the University of Adelaide has received consulting fees on his behalf from Medtronic and Biosense Webster. Dr Sanders has served on the advisory board of Medtronic, Abbott Medical, Boston Scientific, PaceMate, and CathRx; and reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Boston Scientific, and Abbott Medical, and that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott Medical, Boston Scientific, and MicroPort CRM. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. All rights reserved.)
- Published
- 2024
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