Left atrial activation and asymmetric anatomical remodeling in patients with atrial fibrillation: The relation between anatomy and function

Abstract

BackgroundIdentifying patients with advanced left atrial (LA) remodeling before catheter ablation (CA) of atrial fibrillation (AF) is crucial.HypothesisThis study aimed to identify echocardiographic parameters associated with changes in anatomy and conduction properties of the left atrium (LA).MethodsWe examined 75 AF patients prior to CA and measured the intervals from the P‐wave‐onset to four mitral annulus sites by pulsed‐wave tissue Doppler imaging (PW‐TDI). Patients were grouped to an upward U‐pattern (delayed anterior activation) and a downward D‐pattern (earliest LA activation anterior). CT‐data were used to measure the LA volume (LAV). LAV was divided into anterior‐ (LA‐A) and posterior‐parts by a plane, parallel to the posterior wall and between the veins and the appendage, to calculate the asymmetry index (ASI = LA‐A/LAV).ResultsPatients with U‐pattern (n = 66) had a higher ASI (65 ± 6 vs. 61 ± 3%, p = .014), older age (61 ± 11 vs. 51 ± 11 years, p = .03) and more diastolic dysfunction (71 vs. 22%, p = .008) Multivariate regression showed that age (OR 1.1 per year, CI 1.007–1.199) and diastolic dysfunction (OR 6.36, CI 1.132–35.7, p = .036) were independent predictors of the U‐pattern. Diastolic dysfunction (B 4.49, CI 1.61–7.37, p = .003) was the only independent predictor of ASI in linear regression analysis.ConclusionAF patients with a U‐pattern have an increased LA asymmetry. Diastolic dysfunction is a common cause of this LA activation and remodeling. Therefore, detection of a U‐pattern signifies patients with advanced AF and may facilitate selection for an appropriate ablation strategy.

P-wave duration and atrial fibrillation recurrence after catheter ablation: a systematic review and meta-analysis

“… 27 More specifically, this conduction delay at the Bachmann bundle level has been defined as pIAB or aIAB ( Graphical Abstract ). This results in atrial remodelling and asynchronous LA contraction, 28 , 29 but can also appear without LA enlargement as a surrogate of AF substrate. 1 In fact, aIAB has been described as a separate clinical entity, called ‘Bayes’ syndrome’, that has been associated with AF or other atrial arrhythmias and an increased stroke, dementia and mortality risk.…”

Biatrial volume ratio predicts low voltage areas in atrial fibrillation

“…As previously described, LA remodeling is associated with later stages of AF progression resulting from risk factors like aging, hypertension, left ventricular (LV) diastolic dysfunction and an altered electromechanical activation. [23][24][25][26] LV stiffness results into higher LA pressure with reduced LA emptying and consequent atrial dilatation. 23 Described pathologic changes represent a common pathway associated with interatrial delay seen as biphasic Pwave in ECG and caused by deterioration of the Bachmann bundle conduction, and finally impaired electromechanical LA activation.…”

“…23 Described pathologic changes represent a common pathway associated with interatrial delay seen as biphasic Pwave in ECG and caused by deterioration of the Bachmann bundle conduction, and finally impaired electromechanical LA activation. 25 These pathophysiologic changes contribute to advanced remodeling and wall deformation that has been associated with LVA. 27 Our study supplement these findings of side specific pathophysiological LA changes (especially in relation to RAV) and emphasize the need for accurate pre-procedural LA assessment.…”

“…This is in line with our previous studies that emphasized the importance of LV diastolic dysfunction, electro-anatomical dysfunction for asymmetric LA remodeling, and ablation outcomes. [23][24][25] Future studies should thus focus on the LA size and its proportional enlargement in relation to the RA, when assessing patients prior to an AF ablation procedure.…”