Velocity encoded cardiovascular magnetic resonance to assess left atrial appendage emptying.
BACKGROUND
The presence of impaired left atrial appendage (LAA) function identifies patients who are prone to thrombus formation in the LAA and therefore being at high risk for subsequent cardioembolic stroke. LAA function is typically assessed by measurements of LAA emptying velocities using transesophageal echocardiography (TEE) in clinical routine. This study aimed at evaluating the feasibility of assessing LAA emptying by velocity encoded (VENC) cardiovascular magnetic resonance (CMR).


METHODS
This study included 30 patients with sinus rhythm (n = 18) or atrial fibrillation (n = 12). VENC-CMR velocity measurements were performed perpendicular to the orifice of the LAA. Peak velocities were measured of passive diastolic LAA emptying (e-wave) in all patients. Peak velocities of active, late-diastolic LAA emptying (a-wave) were assessed in patients with sinus rhythm. Correlation and agreement was analyzed between VENC-CMR and TEE measurements of e- and a-wave peak velocities.


RESULTS
A significant correlation and good agreement was found between VENC-CMR and TEE measurements of maximal e-wave velocities (r = 0.61, P < 0.001; mean difference 0 ± 10 cm/s). The a-wave was detectable by VENC-CMR in all patients with sinus rhythm. Correlation was also significant for measurements of peak a-wave velocities between VENC-CMR and TEE (r = 0.71, P < 0.001). There was no significant correlation of LAA emptying velocities with clinical characteristics and only a modest negative correlation of passive LAA emptying with LA function.


CONCLUSIONS
The assessment of active and passive LAA emptying by VENC-CMR is feasible. Further evaluation is required of potential future clinical applications such as risk stratification for cardioembolic stroke.
Center for Cardiology and Cardiovascular Surgery, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D - 20246, Hamburg, Germany. ka.muellerleile@uke.de
Kai
K
Muellerleile
Arian
A
Sultan
Michael
M
Groth
Daniel
D
Steven
Boris
B
Hoffmann
Gerhard
G
Adam
Gunnar K
GK
Lund
Thomas
T
Rostock
Stephan
S
Willems
D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology; D016279:Atrial Function, Left / Q000502:physiology*; D001783:Blood Flow Velocity; D017548:Echocardiography, Transesophageal; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015203:Reproducibility of Results; D013318:Stroke Volume