Introduction: Quantification of left ventricular function in patients with atrial fibrillation (AF) is challenging due to inconsistent RR-intervals with resulting alterations in ventricular filling and ejection. Speckle tracking imaging was demonstrated in animal models to predict subtle changes more sensitive than conventional determination of left-ventricular ejection fraction (LVEF) using Simpsons-method. We aimed to investigate to importance of speckle-trackle imaging versus conventional echocardiography in atrial fibrillation-patients with and without heart failure.

Methods: Patients with persistent atrial fibrillation underwent concomitant conventional echocardiography and speckle-tracking imaging in AF and sinus rhythm. Left-ventricular function was determined from six consecutive beats (in AF) and three consecutive beats (in sinus rhythm). LVEF was calculated using Simpson’s biplane method. Left-ventricular function using speckle tracking imaging was expressed as global longitudinal strain (GLS). All patients underwent echocardiography in AF and within 24 hours from electrocardioversion to sinus rhythm. Patients with impaired LVEF (<40%) in AF underwent repeat echocardiography at day 30 to identify patients with AF-induced cardiomyopathy.

Results: A total of 21 patients (mean LVEF 40±12%) were included. Eleven patients had heart failure with impaired LVEF in AF (mean LVEF 30±8%). Correlation of LVEF to GLS was good and comparable in AF (Spearman’s rho 0.784) and sinus rhythm (Spearman’s rho 0.800). In patients with heart failure, sinus rhythm restoration lead to a rapid (within 24h) increase in LFEV by 8.7±6.0%, and a further mid-term (within 30 days) improvement of 7.5±6.1%. Similarly, the majority of improvement with sinus rhythm restoration using speckle tracking was observed within the initial 24h following cardioversion (3.3±2.8% within 24h and 2.6±4.4 within 30 days).

Conclusion: Sinus rhythm restoration in patients with atrial fibrillation-associated heart failure leads to a rapid improvement of left-ventricular function as evidenced using conventional and speckle tracking imaging within the initial 24h. The correlation of LVEF to GLS is high in AF as well as in SR, and both methods seem equally appropriate to determine left-ventricular function in this context.