Comparative analysis of conventional echocardiographic parameters of atrial function using left atrial strain as the reference standard
I Rodrigues, F Nunes, A Goncalves, F Sousa, L Moura, M Almeida, A Lobo, F S Nunes, F Sampaio, P Fonseca, R Fontes-CarvalhoAbstract
Background
Left atrial (LA) strain is currently the most validated echocardiographic parameter for the assessment of LA function. Additional techniques, including peak transmitral A wave velocity, atrial fraction, and tissue Doppler A′ velocity, may provide complementary information. These parameters are less frequently used in routine clinical practice and remain under-validated.
Aim
To compare conventional echocardiographic parameters of atrial function in their association with LA strain and to determine which parameter demonstrates the strongest correlation and discriminative performance for identifying LA dysfunction.
Methods
This prospective observational study included patients with atrial fibrillation (AF) undergoing catheter ablation between March 2025 and January 2026. Transthoracic echocardiography was performed at three time points: pre-procedure, immediately post-procedure, and at 3-month follow-up. In addition to LA strain, the following indices of LA function were assessed: peak transmitral A-wave velocity, atrial fraction (VTIA-wave / VTImitral-inflow), and mean tissue Doppler A′ velocity. Statistical analyses were restricted to echocardiographic studies performed in sinus rhythm. LA dysfunction was defined as LA strain ≤18%. The study endpoints were to determine which atrial functional parameter demonstrated the strongest association with LA strain and the best discriminative power for LA dysfunction.
Results
A total of 229 echocardiographic studies were performed in 100 patients; 200 studies were acquired in sinus rhythm and included in the final analysis. Mean LA strain was 22.3 ± 8.9%, peak A-wave velocity 57.8 ± 19.3 cm/s, atrial fraction 27.2 ± 8.5%, and mean A′ velocity 8.4 ± 2.7 cm/s. Mean A′ velocity demonstrated the strongest correlation with LA strain (r = 0.561, p < 0.001 vs r = 0.261 for peak A-wave velocity and r = 0.159 for atrial fraction). In ROC curve analysis, mean A′ velocity showed the highest discriminative ability for detecting LA dysfunction (area under the curve [AUC] 0.78; 95% confidence interval [CI] 0.70–0.85; p < 0.001). The optimal cut-off value for identifying reduced LA strain was 6.8 cm/s. In multivariable logistic regression analysis, mean A′ velocity was the only parameter independently associated with LA dysfunction (OR 1.62; p < 0.001).
Conclusions
Among conventional echocardiographic indices of atrial function, mean tissue Doppler A′ velocity demonstrated the strongest association with LA strain and the highest discriminative performance for identifying LA dysfunction. These findings support its role as the most reliable conventional surrogate of LA functional impairment.