Introduction: Atrial cardiomyopathy (AC) establishes links between atrial fibrillation (AF), atrial mechanical dysfunction, structural remodeling and thromboembolic events. Early diagnosis of AC may have implications for AF-treatment and stroke risk prevention. To date, however, no defined clinical parameter set exists for the diagnosis of AC. Modern endocardial contact-mapping systems provide high-resolution electroanatomical (EA) maps of the left atrium, display myocardial substrate based on impaired signal amplitude and allow invasive characterization of AC. Correlation of invasively assessed AC using a novel, multipolar mapping catheter (Octaray®, Biosense Webster, limited market release) and left atrial (LA) echo parameters could form the basis of an echo-parameter set that allows noninvasive diagnosis and characterization of AC.

Aims: Definition of an echo-parameter set for non-invasive diagnosis/characterization of invasively defined AC.

Methods: 123 patients undergoing primary pulmonary vein isolation (PVI) for paroxysmal or persistent AF between 08/22 and 05/23 were retrospectively identified. 50 patients (pts.) fulfilling inclusion criteria were analysed. Inclusion criteria consisted of i) EA mapping using a novel multipolar mapping catheter (Octaray®) ii), acquisition of voltage maps in sinus rhythm (SR) with at least 5000 points/map, iii) transthoracic echocardiography acquired in SR ≤ 48 hours before PVI. Exclusion criteria were previous LA ablation. EA maps with a voltage threshold of 0.5 – 1.0 mV were generated. Based on voltage maps we assessed total LA volume and area and total LA low voltage area in every patient; pulmonary veins were excluded before analysis. We defined a total LA low voltage area ≥10 cm² as clinically relevant AC (rAC). NTproBNP levels were measured and we assessed LA volumes, LA total, active and passive ejection fraction (EF), LA strain (contraction, conduit, reservoir) and atrial conduction times.

Results: 70% were male, mean age was 62 (±11) years and persistent AF was present in 70% of pts. 6287 (±1492) points/map were acquired. Invasively assessed LA volume resp. area were 150 (±26) ml resp. 240 (±35) cm². LA static and dynamic echo parameters differed significantly between pts. with i) rAC vs. no AC and ii) persistent vs. paroxysmal AF. LA volume index (LAVI) was larger in group rAC compared to group no AC: 42 (±15.7) vs. 31 (±7.3) ml/m², p < 0.05. 3D LAEF was diminished in group rAC vs. group no AC: 33 (±10.8) vs. 44 (±6.9) %; p< 0.005. LA reservoir strain was -16 (±6.1) % in group rAC and -25 (±6.6) % in group no AC (p<0.001) and LAVI/a’ was larger in group rAC than in group no AC: 637 vs. 306; p < 0.005. Total atrial conduction time, a marker displaying EA coupling, differed between groups: rAC 167 (±41) ms vs. noAC 137 (±23) ms, p < 0.05. NTproBNP levels were higher in group rAC compared to group no AC: 516 (±378) pg/ml vs. 120 (±6.9) pg/ml, p<0.005. Ongoing analysis comprises semi-automated investigation of voltage distribution and LA conduction velocities as novel measures of AC.

Conclusion: Static and dynamic LA echo parameters differ significantly between pts. with and without invasively defined rAC. Thus, this retrospective analysis could form the basis of an echo-parameter set that allows non-invasive diagnosis and characterization of AC, thereby potentially improving i) individualized outcome prediction of AF-ablation and ii) individualized assessment of stroke risks.