The index-beat approach for echocardiographic assessment in atrial fibrillation improved reproducibility (LVEF coefficient of variation 32% vs 51%) and was quicker to perform (P<0.001).
Cross-Sectional (n=160)
Blinded protocol
Does the index-beat approach improve reproducibility and time efficiency compared to conventional averaging of consecutive beats for echocardiographic assessment in patients with atrial fibrillation?
The index-beat approach for echocardiography in patients with atrial fibrillation improves reproducibility and saves time compared to conventional multi-beat averaging, without compromising validity.
Absolute Event Rate: 32% vs 51%
OBJECTIVE: To improve the echocardiographic assessment of heart failure in patients with atrial fibrillation (AF) by comparing conventional averaging of consecutive beats with an index-beat approach, whereby measurements are taken after two cycles with similar R-R interval. METHODS: Transthoracic echocardiography was performed using a standardised and blinded protocol in patients enrolled in the RATE-AF (RAte control Therapy Evaluation in permanent Atrial Fibrillation) randomised trial. We compared reproducibility of the index-beat and conventional consecutive-beat methods to calculate left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and E/e' (mitral E wave max/average diastolic tissue Doppler velocity), and assessed intraoperator/interoperator variability, time efficiency and validity against natriuretic peptides. RESULTS: 160 patients were included, 46% of whom were women, with a median age of 75 years (IQR 69-82) and a median heart rate of 100 beats per minute (IQR 86-112). The index-beat had the lowest within-beat coefficient of variation for LVEF (32%, vs 51% for 5 consecutive beats and 53% for 10 consecutive beats), GLS (26%, vs 43% and 42%) and E/e' (25%, vs 41% and 41%). Intraoperator (n=50) and interoperator (n=18) reproducibility were both superior for index-beats and this method was quicker to perform (p<0.001): 35.4 s to measure E/e' (95% CI 33.1 to 37.8) compared with 44.7 s for 5-beat (95% CI 41.8 to 47.5) and 98.1 s for 10-beat (95% CI 91.7 to 104.4) analyses. Using a single index-beat did not compromise the association of LVEF, GLS or E/e' with natriuretic peptide levels. CONCLUSIONS: Compared with averaging of multiple beats in patients with AF, the index-beat approach improves reproducibility and saves time without a negative impact on validity, potentially improving the diagnosis and classification of heart failure in patients with AF.
Bunting et al. (Wed,) conducted a cross-sectional in Atrial fibrillation (n=160). Index-beat approach vs. Conventional averaging of consecutive beats (5 or 10 beats) was evaluated on Within-beat coefficient of variation for left ventricular ejection fraction (LVEF). The index-beat approach for echocardiographic assessment in atrial fibrillation improved reproducibility (LVEF coefficient of variation 32% vs 51%) and was quicker to perform (P<0.001).