Clinical value of assessment of left atrial late gadolinium enhancement in patients undergoing ablation of atrial fibrillation.

Left atrial (LA) fibrosis begets atrial fibrillation (AF). Cardiovascular magnetic resonance (CMR) using the late gadolinium enhancement (LGE) technique might visualize the LA fibrosis and thus help to choose an appropriate strategy for treatment of AF. In this regard, we investigated whether the extent of preablation LA LGE would predict AF recurrence after ablation in a non-selected patient population. CMR was performed in 95 patients before radiofrequency ablation of AF. An interpretable scan was available in 73 patients (age, 59 ± 8 years; men, 71%; persistent/paroxysmal AF, 55/45%). The extent of LA LGE was quantified by three established thresholding techniques. In addition, CMR was used to quantify LA volume and reservoir function. The patients were followed for AF recurrence for 1.3 ± 0.8 years. The arrhythmia recurred in 29 (40%) of the patients. The extent of LA LGE did not differ between paroxysmal and persistent AF and it did not predict the AF recurrence. Moreover, the extent of LA LGE did not correlate with LA volume, reservoir function and bipolar voltage. Our data indicate a limited value of a routine assessment of LA LGE before ablation of AF. Further experimental and clinical researches should be done before applying the method to a wide clinical practice.

Sramko M ，Peichl P ，Wichterle D ，Tintera J ，Weichet J ，Maxian R ，Pasnisinova S ，Kockova R ，Kautzner J ... -  《-》

Evaluation of quantification methods for left arial late gadolinium enhancement based on different references in patients with atrial fibrillation.

Hwang SH ，Oh YW ，Lee DI ，Shim J ，Park SW ，Kim YH ... -  《-》

Lack of regional association between atrial late gadolinium enhancement on cardiac magnetic resonance and atrial fibrillation rotors.

The extent of left atrial (LA) late gadolinium enhancement (LGE), as a surrogate for fibrosis, has been associated with atrial fibrillation (AF) recurrence after catheter ablation. Furthermore, there is ex vivo evidence that islands of fibrosis may anchor fibrillatory rotors. The purpose of this study was to examine the anatomical association of AF rotors with LA and right atrial (RA) LGE on cardiac magnetic resonance. The cohort included 9 patients with persistent AF (mean age 61.1 ± 9.7 years) who underwent LGE cardiac magnetic resonance before AF ablation using the focal impulse and rotor modulation system. The extent of LA and RA LGE was quantified globally and in each of the 7 sectors: LA posterior/inferior wall, anterior wall, roof, left and right pulmonary vein antra, and RA lateral and septal regions. The multivariable association of rotor incidence with global and per sector LGE extent was examined using multivariable Bernoulli logistic regression estimated by generalized estimating equations. The mean RA and LA volumes were 113.2 ± 37.31 and 143.03 ± 58.25 mL, respectively. The mean RA and LA LGE burden was 17.2% ± 11.0% and 17.4% ± 14.4%, respectively. A total of 18 LA rotors and 9 RA rotors were identified in all patients. No univariable or multivariable association was observed between global or per sector LGE extent and focal impulse and rotor modulation rotor incidence. In this cohort of patients, there was no association between AF rotor incidence and the global or regional extent of RA and LA LGE.

Chrispin J ，Gucuk Ipek E ，Zahid S ，Prakosa A ，Habibi M ，Spragg D ，Marine JE ，Ashikaga H ，Rickard J ，Trayanova NA ，Zimmerman SL ，Zipunnikov V ，Berger RD ，Calkins H ，Nazarian S ... -  《-》

Association of left atrial function and left atrial enhancement in patients with atrial fibrillation: cardiac magnetic resonance study.

Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF. LA structure and function was measured in 90 patients with AF (age 61±10 years; 76% men) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain, LA systolic strain rate, and early and late diastolic strain rates were measured using cine-cardiac magnetic resonance images acquired during sinus rhythm. The degree of LGE was quantified. Compared with patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (56±17 versus 49±13 mL/m(2); P=0.036), and increased LGE (27.1±11.7% versus 36.8±14.8%; P<0.001). Aside from LA active emptying fraction, all LA parameters (passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate) were lower in patients with persistent AF (P<0.05 for all). Healthy volunteers had less LGE and higher LA functional parameters compared with patients with AF (P<0.05 for all). In multivariable analysis, increased LGE was associated with lower LA passive emptying fraction, peak global longitudinal LA strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate (P<0.05 for all). Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking cardiac magnetic resonance may add important information about the physiological importance of LA fibrosis.

Habibi M ，Lima JA ，Khurram IM ，Zimmerman SL ，Zipunnikov V ，Fukumoto K ，Spragg D ，Ashikaga H ，Rickard J ，Marine JE ，Calkins H ，Nazarian S ... -  《-》

Automated analysis of atrial late gadolinium enhancement imaging that correlates with endocardial voltage and clinical outcomes: a 2-center study.

For late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) assessment of atrial scar to guide management and targeting of ablation in atrial fibrillation (AF), an objective, reproducible method of identifying atrial scar is required. To describe an automated method for operator-independent quantification of LGE that correlates with colocated endocardial voltage and clinical outcomes. LGE CMR imaging was performed at 2 centers, before and 3 months after pulmonary vein isolation for paroxysmal AF (n = 50). A left atrial (LA) surface scar map was constructed by using automated software, expressing intensity as multiples of standard deviation (SD) above blood pool mean. Twenty-one patients underwent endocardial voltage mapping at the time of pulmonary vein isolation (11 were redo procedures). Scar maps and voltage maps were spatially registered to the same magnetic resonance angiography (MRA) segmentation. The LGE levels of 3, 4, and 5SDs above blood pool mean were associated with progressively lower bipolar voltages compared to the preceding enhancement level (0.85 ± 0.33, 0.50 ± 0.22, and 0.38 ± 0.28 mV; P = .002, P < .001, and P = .048, respectively). The proportion of atrial surface area classified as scar (ie, >3 SD above blood pool mean) on preablation scans was greater in patients with postablation AF recurrence than those without recurrence (6.6% ± 6.7% vs 3.5% ± 3.0%, P = .032). The LA volume >102 mL was associated with a significantly greater proportion of LA scar (6.4% ± 5.9% vs 3.4% ± 2.2%; P = .007). LA scar quantified automatically by a simple objective method correlates with colocated endocardial voltage. Greater preablation scar is associated with LA dilatation and AF recurrence.

Malcolme-Lawes LC ，Juli C ，Karim R ，Bai W ，Quest R ，Lim PB ，Jamil-Copley S ，Kojodjojo P ，Ariff B ，Davies DW ，Rueckert D ，Francis DP ，Hunter R ，Jones D ，Boubertakh R ，Petersen SE ，Schilling R ，Kanagaratnam P ，Peters NS ... -  《-》