The aim of this work is to identify left atrial fibrosis in a group of consecutive patients with Atrial Fibrillation (AF),
using a Late Enhancement Magnetic Resonance sequence (LE-MR),
and its validation by comparison with Electroanatomic Mapping (EAM),
currently considered the “gold standard” in the evaluation of fibrosis.
The importance of left atrial fibrosis identification has recently been underlined in the Expert Consensus Statement of the Heart Rhythm Society ,
in terms of treatment and prognosis .
Methods and Materials
22 patients with AF,
mean age 61 years (range 47-74 years)
One week before RadioFrequency Catheter Ablation (RFCA) patients underwent cardiac MR on 1.5 T scanner (Magnetom,
Siemens Medical Systems,
Germany) with a 12-element body coil.
A contrast-enhanced MR angiography,
using real-time bolus tracking after a bolus injection of 10 ml of gadobenate dimeglumine (Multihance,
Italy 0.1 mmol/kg) at a rate of 2 mL/s,
followed by 40 mL of saline flush was acquired to evaluate anatomical complex...
4 patients were excluded for the poor quality of images.
Optimal anatomical concordance was 83% (15/18 patients): in 8 patients was 7/7segments (Fig.
2) in 7 patients was 6/7 segments; in 2/18 patients the anatomical concordance was 4/7 segments and in one patient was 3/7 segments (Fig.
The difference in the classification of the segments between the two methods was statistically not significant (McNemar test,
P = 0143); also the correlation between the findings of fibrosis was significant,
with Cohen's kappa index =0.696 (95%...
DISCUSSION AND LIMITS
Results confirm that there is a good correlation between segments of LE-MR and areas of low voltage to the EAM [2-3].
Statistical analysis showed a VPN of LE rather high (93.8%) compared with a considerable number of false positives,
which resulted in a PPV of 73.3%; artifacts present in the MR images,
such as the often observed in the right inferior PV ,
may have affected results,
leading to an overestimation of fibrosis.
Some comparison studies [5-6] show an EAM spatial error...
2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection,
Patient Management and Follow-up,
and Research Trial Design.
A report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation.
Heart Rhythm 2012
Detection and quantification of left atrial structural remodeling with delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation.
Atrial fibrosis helps select the appropriate patient and strategy...
Department of Radiology-APSS of Trento
L.go Medaglie d’Oro,