Author + information
- Susanne Löbe, MD∗ (, )
- Helge Knopp, MD,
- Thuy-Vi Le, cand. med.,
- Sotirios Nedios, MD,
- Timm Seewöster, MD,
- Kerstin Bode, MD,
- Philipp Sommer, MD,
- Andreas Bollmann, MD, PhD,
- Gerhard Hindricks, MD and
- Borislav Dinov, MD
- ↵∗Department of Electrophysiology, University of Leipzig – Helios Heart Center, Struempellstrasse 39, 04289 Leipzig, Germany
Identifying patients with advanced left atrial (LA) remodeling before catheter ablation (CA) of atrial fibrillation (AF) is of crucial importance. Recently, we proposed a simple noninvasive method to evaluate LA activation and asynchrony using pulsed-wave tissue Doppler imaging (PW-TDI) (1). In that study, we investigated the effects of LA asynchrony on the presence of LA scar and AF recurrences after CA.
Patients with AF referred for CA were prospectively investigated using PW-TDI. Before CA, the intervals from the onset of P-wave to A′ (P-A′) were measured at the septal, lateral, anterior, and inferior mitral annulus. In the LA activation sequence, the difference between the longest and the shortest P-A′ (DLS), as well as the SD of all 4 values (SD4), were calculated to measure LA asynchrony as previously described (1). Pulmonary vein isolation was successfully performed in all patients. Point-by-point electroanatomical voltage maps of the LA in sinus rhythm were created and areas with low voltage (< 0.5 mV) were delineated. The 1-year AF recurrence was monitored with a 7-day Holter electrocardiogram.
The study cohort consisted of 125 patients (age 59.7 ± 11.7 years; 41% women), of them, 95 (76%) with paroxysmal AF (PAF) and 30 (24%) with persistent AF (PerAF). Of 100 patients with voltage maps, LA low-voltage areas (LA scar positive) were observed in 19 cases. The baseline clinical and echocardiographic characteristics, including LA dimensions, were comparable between patients with and without AF recurrences. Patients with PAF and PerAF had similar clinical characteristics with exception of the older age in PerAF (p = 0.03). We observed that patients with AF recurrence had larger DLS (43 ± 16 ms vs. 35 ± 16 ms; p = 0.01) and SD4 (20 ± 8 ms vs. 16 ± 7 ms; p = 0.004) as compared with those without. LA scar–positive patients had longer DLS (46 ± 19 ms vs. 36 ± 16 ms; p = 0.04) and SD4 (23 ± 9 ms vs. 16 ± 7 ms; p = 0.009) in comparison with no LA scar cases. Likewise, patients with PerAF had longer DLS (44 ± 21 ms vs. 35 ± 14 ms; p = 0.04) and SD4 (21 ± 10 ms vs. 16 ± 6 ms; p = 0.02) as compared with PAF. In the multivariate analysis, the DLS (hazard ratio: 1.02, p = 0.008) and the SD4 (hazard ratio: 1.35; p = 0.031) were predictors for AF recurrence and presence of LA scar, respectively. LA size (p = 0.08) and age (p = 0.35) did not correlate with AF recurrences in multivariate analysis. Receiver-operating characteristic analysis for the asynchrony indexes showed that P-A′ at the anterior LA was best to discriminate between patients with and without LA low-voltage areas (area under the curve: 0.748; p = 0.001).
Furthermore, 2 distinct patterns of LA activation were observed. A downward LA activation directed from anterosuperior to inferoposterior, consistent with activation through the Bachmann’s bundle (D-pattern) and an upward LA activation directed oppositely from inferior to anterosuperior (U-pattern) (Figure 1). U-pattern was observed in 33 (87%) patients with AF recurrence and in 72 (90%) without AF (p = 0.40). U-pattern was observed in 84 (88%) patients with PAF compared with 26 (87%) with PerAF (p = 0.80). However, U-pattern was observed in all patients with LA scar and less frequently in those demonstrating normal LA-voltage: 19 (100%) LA scar–positive versus 68 (84%) LA scar–negative patients (p = 0.015).
Previous studies have used PW-TDI to measure total atrial conduction time at the lateral mitral annulus as a predictor for AF recurrences after CA (2). In contrast to the latter, we measured the local activation at 4 LA sites and calculated two novel indexes of LA asynchrony. The LA asynchrony indexes were more pronounced in patients with persistent AF, presence of low-voltage areas, and AF recurrences after CA. Although these differences are small in absolute numbers, they represent approximately one-quarter to one-third of the baseline values.
The pronounced delay at the anterior left atrium resulted in a typical U-pattern LA activation in AF patients. It was observed in all patients with LA scar and less frequently in LA scar negative cases. This finding suggests that block the Bachmann’s bundle or asymmetrical changes in LA geometry can be associated with more advanced LA remodeling.
In the clinical practice, these simple indexes, adding to established predictors of AF recurrences after CA, can be useful to identify patients with more advanced LA remodeling before CA, as well as patients at higher risk for AF recurrences after CA. Limitations of the current study are the smaller proportion of patients with PerAF and LA scars.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Löbe and Knopp contributed equally to this paper and are joint first authors.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- 2018 American College of Cardiology Foundation