Peak Left Atrial Appendage Emptying Velocity Remains Reduced in Atrial Fibrillation during Continuous Flow Left Ventricular Assist Device Support

Abstract

Purpose Although regions of stasis such as the left atrial appendage (LAA) may be potential sites of thrombus formation during atrial fibrillation (AF), its thrombotic contribution during high flow mechanical unloading is unknown. Moreover, registry studies only show a mixed association of AF and stroke during continuous flow left ventricular assist device (CF LVAD) support. Since a lower peak Left Atrial Appendage Emptying Velocity (LAAEV) of less than 40 cm/s during AF, mechanistically contributes to thrombosis and stroke in non-CF LVAD populations, we sought to evaluate the LAAEV in CF LVAD patients with and without AF. Methods We conducted a single center review of patients who had a measurement of the LAAEV by pulsed-waved Doppler by transesophageal echocardiography (TEE). To evaluate at the steady state CF LVAD speed, operating room studies were excluded. CF LVAD patients were categorized into groups with and without AF during TEE and LAAEVs were compared. Matched non-heart failure (HF) and HF patients with and without AF were included as controls. Results Thirty eight patients with a CF LVAD had a peak LAAEV measurement by TEE, of whom 15 were in AF. There were no differences in age (AF: 58±11 vs. no AF: 59±13 years, p=0.8) and gender (AF: 20% vs. no AF: 9% female, p=0.6). The peak LAAEV was significantly lower for CF LVAD patients in AF (33±18 cm/s) in comparison to those in sinus rhythm (SR) (60±20 cm/s, p Conclusion Despite mechanical unloading, the LAAEV remains reduced in patients with AF. Further studies are warranted to investigate the relation between reduced LAAEV and thromboembolism during CF LVAD support.