Velocity encoded cardiovascular magnetic resonance to assess left atrial appendage emptying

Abstract

BackgroundThe 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).MethodsThis 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.ResultsA 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.ConclusionsThe 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.

Cardiovascular Magnetic Resonance Demonstrates Reversible Atrial Dysfunction After Catheter Ablation of Persistent Atrial Fibrillation

“…LA-AEF improved in 19 (95%) patients from BL to FU. Median LA-AEF significantly improved from 18 (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)% at BL to 25 (22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)% at FU (P = 0.0001; Fig. 3A).…”

“…15 LAA emptying was assessed on a VENC-CMR slice perpendicular to the orifice of the LAA. 16 Typical imaging parameters of VENC-CMR were Voxel size 1.37 × 1.37 × 6 mm, 3 echo time = 3.3 milliseconds, time to repetition = 5.0 milliseconds, flip angle = 15 • , 50 frames per RR interval, encoding velocity was set to 100 cm/s, parallel acquisition technique = SENSE. Longaxes edema-sensitive black-blood T 2 -weighted CMR was performed to assess peri-atrial edema using a triple inversionrecovery turbo-spin-echo sequence as used in clinical routine for assessing LV edema.…”

“…1A and B). Active LAA emptying was quantified by measurements of peak a-wave velocities from VENC-CMR flow profiles perpendicular to the LAA orifice as described before 16 (Fig. 1C).…”

“…[11][12][13][14] Cardiovascular magnetic Manuscript received 27 December 2012; Revised manuscript received 27 January 2013; Accepted for publication 1 February 2013. doi: 10.1111/jce.12125 resonance (CMR) offers noninvasive assessment of active left (LA) and right atrial (RA) as well as LAA function. 15,16 Furthermore, CMR has the ability to detect myocardial inflammation in several conditions. 17 Thus, we evaluated the course of LA, RA, and LAA function as well as peri-atrial edema as surrogates for atrial injury following persistent AF ablation using CMR.…”

Cardiovascular Magnetic Resonance Imaging for Assessment of Cardiac Thrombus

“…12 Similar to LV thrombus, both left atrial appendage size and velocity-potential structural risk factors for thrombus-can be assessed by CMR. 13,14 However, head-tohead comparisons between DE-CMR and the established clinical reference of transesophageal echo for actual identification of thrombus are lacking.…”