Magnetic resonance imaging of the left atrial appendage post pulmonary vein isolation: Implications for percutaneous left atrial appendage occlusion.
BACKGROUND
There is increasing interest in performing left atrial appendage (LAA) occlusion at the time of atrial fibrillation (AF) ablation procedures. However, to date there has been no description of the acute changes to the LAA immediately following pulmonary vein (PV) isolation and additional left atrium (LA) substrate modification. This study assessed changes in the size and tissue characteristics of the LAA ostium in patients undergoing PV isolation.


METHODS
This series included 8 patients who underwent cardiovascular magnetic resonance evaluation of the LA with delayed enhancement magnetic resonance imaging and contrast enhanced 3-D magnetic resonance angiography pre-, within 48 h of, and 3 months post ablation. Two independent cardiac radiologists evaluated the ostial LAA diameters and area at each time point in addition to the presence of gadolinium enhancement.


RESULTS
Compared to pre-ablation values, the respective median differences in oblique diameters and LAA area were +1.8 mm, +1.7 mm, and +0.6 cm(2) immediately post ablation (all NS) and -2.7 mm, -2.3 mm, and -0.5 cm(2) at 3 months (all NS). No delayed enhancement was detected in the LAA post ablation.


CONCLUSIONS
No significant change to LAA diameter, area, or tissue characteristics was noted after PV isolation. While these findings suggest the safety and feasibility of concomitant PV isolation and LAA device occlusion, the variability in the degree and direction of change of the LAA measurements highlights the need for further study.
Division of Cardiology, Schulich Heart Centre and Department of Medicine, Sunnybrook Health Sciences Centre, Faculty of Medicine, University of Toronto, Ontario, Canada.
Sheldon M
SM
Singh
Department of Medical Imaging, Cardiothoracic Division, Sunnybrook Health Sciences Centre, Faculty of Medicine, University of Toronto, Ontario, Canada.
Laura
L
Jimenez-Juan
Division of Cardiology, Schulich Heart Centre and Department of Medicine, Sunnybrook Health Sciences Centre, Faculty of Medicine, University of Toronto, Ontario, Canada.
Asaf
A
Danon
Department of Medical Imaging, Cardiothoracic Division, Sunnybrook Health Sciences Centre, Faculty of Medicine, University of Toronto, Ontario, Canada.
Gorka
G
Bastarrika
Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Andriy V
AV
Shmatukha
Division of Cardiology, Schulich Heart Centre and Department of Medicine, Sunnybrook Health Sciences Centre, Faculty of Medicine, University of Toronto, Ontario, Canada ; Schulich Heart Research Program and Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada ; Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Ontario, Canada.
Graham A
GA
Wright
Division of Cardiology, Schulich Heart Centre and Department of Medicine, Sunnybrook Health Sciences Centre, Faculty of Medicine, University of Toronto, Ontario, Canada.
Eugene
E
Crystal
AF, atrial fibrillation; Atrial fibrillation; CE-3D MRA, contrast enhanced 3-dimensional magnetic resonance angiography; CMR, cardiovascular magnetic resonance imaging; Catheter ablation; DE-MRI, delayed enhancement magnetic resonance imaging; FOV, field of view; IR, inversion recovery; LA, left atrium; LAA, left atrial appendage; Left atrial appendage occlusion; Magnetic resonance imaging; NEX, number of excitations; PV, pulmonary vein; RF, radiofrequency; TE, echo time; TR, repetition time