Frequent premature atrial contractions impair left atrial contractile function and promote adverse left atrial remodeling

<jats:sec><jats:title>Objectives</jats:title><jats:p>This study assessed if frequent premature atrial contractions (<jats:styled-content style="fixed-case">PAC</jats:styled-content>s) were associated with decreased left atrial (<jats:styled-content style="fixed-case">LA</jats:styled-content>) strain and adverse remodeling.</jats:p></jats:sec><jats:sec><jats:title>Background</jats:title><jats:p>Left atrial dysfunction and enlargement increases risk of stroke. If frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content>s cause <jats:styled-content style="fixed-case">LA</jats:styled-content> dysfunction and remodeling, <jats:styled-content style="fixed-case">PAC</jats:styled-content> suppressive therapy may be beneficial.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Inclusion criteria were age ≥18 years and sinus rhythm. Exclusion criteria were atrial fibrillation or any etiology for <jats:styled-content style="fixed-case">LA</jats:styled-content> enlargement. Hundred and thirty‐two patients with frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content>s (≥100/24 hours) by Holter were matched to controls. Speckle tracking strain of the left atrium was performed from the 4‐chamber view. Strain measurements were <jats:styled-content style="fixed-case">LA</jats:styled-content> peak contractile, reservoir and conduit strain and strain rates.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>In the frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content> vs control group, <jats:styled-content style="fixed-case">PAC</jats:styled-content>s were more frequent (1959 ± 3796 vs 28 ± 25/24 hours, <jats:italic>P</jats:italic> < .0001). <jats:styled-content style="fixed-case">LA</jats:styled-content> peak contractile strain was reduced in the group with frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content>s vs controls (−7.85 ± 4.12% vs −9.33 ± 4.45%, <jats:italic>P</jats:italic> = .006). <jats:styled-content style="fixed-case">LA</jats:styled-content> peak late negative contractile strain rate was less negative in the frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content> vs control group (−0.63 ± 0.27 s<jats:sup>−1</jats:sup> vs −0.69 ± 0.32 s<jats:sup>−1</jats:sup>, <jats:italic>P</jats:italic> = .051). <jats:styled-content style="fixed-case">LA</jats:styled-content> reservoir and conduit strain and strain rates did not differ. <jats:styled-content style="fixed-case">LA</jats:styled-content> volume index (<jats:styled-content style="fixed-case">LAVI</jats:styled-content>) was larger in the frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content> vs control group (26.6 ± 7.8 vs 24.6 ± 8.8 mL/m<jats:sup>2</jats:sup>, <jats:italic>P</jats:italic> < .05). Frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content>s were an independent predictor of reduced <jats:styled-content style="fixed-case">LA</jats:styled-content> peak contractile strain and reduced <jats:styled-content style="fixed-case">LA</jats:styled-content> peak late negative contractile strain rate.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Patients with frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content>s have reduced <jats:styled-content style="fixed-case">LA</jats:styled-content> peak contractile strain and strain rates and larger <jats:styled-content style="fixed-case">LAVI</jats:styled-content> compared to controls. Frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content>s are an independent predictor of reduced <jats:styled-content style="fixed-case">LA</jats:styled-content> peak contractile strain and strain rate. These findings support the hypothesis that frequent <jats:styled-content style="fixed-case">PAC</jats:styled-content>s impair <jats:styled-content style="fixed-case">LA</jats:styled-content> contractile function and promote adverse <jats:styled-content style="fixed-case">LA</jats:styled-content> remodeling.</jats:p></jats:sec>