P-wave vector magnitude predicts the left atrial low-voltage area in patients with paroxysmal atrial fibrillation

BackgroundAtrial fibrillation (AF) is the most common arrhythmia and a significant burden for healthcare systems worldwide. Presence of relevant atrial cardiomyopathy (ACM) is related to persistent AF and increased arrhythmia recurrence rates after pulmonary vein isolation (PVI).ObjectiveTo investigate the association of left atrial pressure (LAP), left atrial electrical [invasive atrial activation time (IAAT) and amplified p-wave duration (aPWD)] and mechanical [left atrial emptying fraction (LA-EF) and left atrial strain (LAS)] functional parameters with the extent of ACM and their impact on arrhythmia recurrence following PVI.Materials and MethodsFifty patients [age 67 (IQR: 61–75) years, 78% male] undergoing their first PVI for persistent AF were prospectively included. LAP (maximum amplitude of the v-wave), digital 12-lead electrocardiogram, echocardiography and high-density endocardial contact mapping were acquired in sinus rhythm prior to PVI. Arrhythmia recurrence was assessed using 72-hour Holter electrocardiogram at 6 and 12 months post PVI.ResultsRelevant ACM (defined as left atrial low-voltage extent ≥2 cm2 at <0.5 mV threshold) was diagnosed in 25/50 (50%) patients. Compared to patients without ACM, patients with ACM had higher LAP [17.6 (10.6–19.5) mmHg with ACM versus 11.3 (7.9–14.0) mmHg without ACM (p = 0.009)]. The corresponding values for the electrical parameters were 166 (149–181) ms versus 139 (131–143) ms for IAAT (p < 0.0001), 163 (154–176) ms versus 148 (136–152) ms for aPWD on surface-ECG (p < 0.0001) and for the mechanical parameters 27.0 (17.5–37.0) % versus 41.0 (35.0–45.0) % for LA-EF in standard 2D-echocardiography (p < 0.0001) and 15.2 (11.0–21.2) % versus 29.4 (24.9–36.6) % for LAS during reservoir phase (p < 0.0001). Furthermore, all parameters showed a linear correlation with ACM extent (p < 0.05 for all). Receiver-operator-curve-analysis demonstrated a LAP ≥12.4 mmHg [area under the curve (AUC): 0.717, sensitivity: 72%, and specificity: 60%], a prolonged IAAT ≥143 ms (AUC: 0.899, sensitivity: 84%, and specificity: 80%), a prolonged aPWD ≥153 ms (AUC: 0.860, sensitivity: 80%, and specificity: 79%), an impaired LA-EF ≤33% (AUC: 0.869, sensitivity: 84%, and specificity: 72%), and an impaired LAS during reservoir phase ≤23% (AUC: 0.884, sensitivity: 84%, and specificity: 84%) as predictors for relevant ACM. Arrhythmia recurrence within 12 months post PVI was significantly increased in patients with relevant ACM ≥2 cm2, electrical dysfunction with prolonged IAAT ≥143 ms and mechanical dysfunction with impaired LA-EF ≤33% (66 versus 20, 50 versus 23 and 55 versus 25%, all p < 0.05).ConclusionLeft atrial hypertension, electrical conduction slowing and mechanical dysfunction are associated with ACM. These findings improve the understanding of ACM pathophysiology and may be suitable for risk stratification for new-onset AF, arrhythmia recurrence following PVI, and development of novel therapeutic strategies to prevent AF and its associated complications.

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Clinical Outcomes of low-voltage area-guided left atrial linear ablation for non-paroxysmal atrial fibrillation patients

PLoS ONE ◽

10.1371/journal.pone.0260834 ◽

2021 ◽

Vol 16 (12) ◽

pp. e0260834

Author(s):

Hao-Tien Liu ◽

Chia-Hung Yang ◽

Hui-Ling Lee ◽

Po-Cheng Chang ◽

Hung-Ta Wo ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Paroxysmal Atrial Fibrillation ◽

Left Atrial ◽

Low Voltage ◽

Reverse Remodeling ◽

Voltage Mapping ◽

Linear Ablation

Background The therapeutic effect of low-voltage area (LVA)-guided left atrial (LA) linear ablation for non-paroxysmal atrial fibrillation (non-PAF) is uncertain. We aimed to investigate the efficacy of LA linear ablation based on the preexisting LVA and its effects on LA reverse remodeling in non-PAF patients. Methods We retrospectively evaluated 145 consecutive patients who underwent radiofrequency catheter ablation for drug-refractory non-PAF. CARTO-guided bipolar voltage mapping was performed in atrial fibrillation (AF). LVA was defined as sites with voltage ≤ 0.5 mV. If circumferential pulmonary vein isolation couldn’t convert AF into sinus rhythm, additional LA linear ablation was performed preferentially at sites within LVA. Results After a mean follow-up duration of 48 ± 33 months, 29 of 145 patients had drugs-refractory AF/LA tachycardia recurrence. Low LA emptying fraction, large LA size and high extent of LVA were associated with AF recurrence. There were 136 patients undergoing LA linear ablation. The rate of linear block at the mitral isthmus was significantly higher via LVA-guided than non-LVA-guided linear ablation. Patients undergoing LVA-guided linear ablation had larger LA size and higher extent of LVA, but the long-term AF/LA tachycardia-free survival rate was higher than the non-LVA-guided group. The LA reverse remodeling effects by resuming sinus rhythm were noted even in patients with a diseased left atrium undergoing extensive LA linear ablation. Conclusions LVA-guided linear ablation through targeting the arrhythmogenic LVA and reducing LA mass provides a better clinical outcome than non-LVA guided linear ablation, and outweighs the harmful effects of iatrogenic scaring in non-PAF patients.

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The Duration of the Amplified Sinus-P-Wave Identifies Presence of Left Atrial Low Voltage Substrate and Predicts Outcome After Pulmonary Vein Isolation in Patients With Persistent Atrial Fibrillation

JACC: Clinical Electrophysiology ◽

10.1016/j.jacep.2017.12.001 ◽

2018 ◽

Vol 4 (4) ◽

pp. 531-543 ◽

Cited By ~ 20

Author(s):

Amir Jadidi ◽

Björn Müller-Edenborn ◽

Juan Chen ◽

Cornelius Keyl ◽

Reinhold Weber ◽

...

Keyword(s):

Atrial Fibrillation ◽

Pulmonary Vein ◽

Pulmonary Vein Isolation ◽

Left Atrial ◽

Low Voltage ◽

Persistent Atrial Fibrillation ◽

P Wave

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Correlation between the left atrial low‐voltage area and the cardiac function improvement after catheter ablation for paroxysmal atrial fibrillation

Journal of Arrhythmia ◽

10.1002/joa3.12221 ◽

2019 ◽

Vol 35 (5) ◽

pp. 725-732 ◽

Cited By ~ 2

Author(s):

Yosuke Nakatani ◽

Tamotsu Sakamoto ◽

Yoshiaki Yamaguchi ◽

Yasushi Tsujino ◽

Naoya Kataoka ◽

...

Keyword(s):

Atrial Fibrillation ◽

Catheter Ablation ◽

Cardiac Function ◽

Paroxysmal Atrial Fibrillation ◽

Left Atrial ◽

Low Voltage

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P3748Reproducibility of magnetocardiographic imaging of atrial electrophysiology in patients with paroxysmal atrial fibrillation and healthy subjects

European Heart Journal ◽

10.1093/eurheartj/ehz745.0600 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

D Brisinda ◽

G L Guida ◽

A R Sorbo ◽

R Fenici

Keyword(s):

Magnetic Field ◽

Atrial Fibrillation ◽

Paroxysmal Atrial Fibrillation ◽

Left Atrial ◽

Visual Analysis ◽

The Body ◽

P Wave ◽

Atrial Electrophysiology ◽

Pr Interval ◽

Atrial Repolarization

Abstract Since tangential currents are better detectable as magnetic than electric signals at the body surface, magnetocardiographic mapping (MCG) can be more sensitive than ECG to atrial electrophysiologic alteration, such as abnormal interatrial conduction and/or dispersion of atrial repolarization, as mechanisms underlying the occurrence of paroxysmal atrial fibrillation (PAF). We had previously reported that visual analysis of the magnetic field distribution (MFD) dynamics may evidence an inversion of atrial MFD early during the P-wave suggesting atrial repolarization overlapping depolarization along the descending limb of the P-wave (Guida et al 2018). Aim of this study was to systematically evaluate the reproducibility of such observation and to evaluate the reliability of non-invasive MCG imaging of atrial electrophysiology carried out in our unshielded hospital laboratory. Methods MCG was recorded, in sinus rhythm (SR), with an unshielded 36-channel SQUID-system providing about 30–40 fT/√Hz sensitivity in bandwidth DC-250Hz (sampling frequency 1kHz). MCG data of 40 patients with PAF (PAFp) and 40 age-matched healthy controls (HC), with at least two subsequent recordings to evaluate reproducibility and optimal S/N ratio, were retrospectively analyzed. The dynamics of atrial MFD was studied, at 1 ms time resolution, to identify the onset of atrial repolarization (AR), in respect of the P-wave and PR interval duration. To localize atrial sources, the inverse solution was calculated with the Effective Magnetic Dipole (EMD) model, also after subtraction of the atrial repolarization. MCG parameters of atrial electromagnetic vector (EMV) were also calculated. The reproducibility was evaluated with the intraclass correlation coefficient (ICC). Results High resolution analysis of atrial MFD dynamics confirmed that atrial repolarization field overlaps atrial depolarization during the last third of the P-wave in most investigated subjects. Thus, subtraction of average AR MFD is necessary to discover and image the left atrial depolarization pathway. The reproducibility of MCG estimate of atrial MFD and of EMV parameters was good (average ICC >0.7). In PAFp, MCG evidenced abnormality of AR MFD consistent with dispersion of atrial repolarization (Figure 1), as previously reported with simultaneous MCG and MAP recordings (Fenici & Brisinda, 2007); however, such evaluation is reliable only with optimal S/N ratio during the PR interval. Conclusions Unshielded MCG in SR is sensitive enough to non-invasively image atrial electrophysiology. Visual analysis of atrial MFD dynamics with high temporal resolution reproductively confirmed that AR MFD initiates early, within the descending limb of the P-wave, masking the deeper magnetic field generated by left atrial depolarization currents. MCG can image abnormality of AR MFD in PAFp, suggestive of dispersion of atrial action potential duration. Quantitative estimate of atrial EMV parameters differentiates PAFp from HC.

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