Photo Credit: Rasi Bhadramani

The following is a summary of “Embryological Classification of Arrhythmogenic Triggers Initiating Atrial Fibrillation,” published in the November 2024 issue of Cardiology by Ikenouchi, et al.   

Atrial fibrillation (AF) is a common arrhythmia linked to genetic factors, and pulmonary vein isolation (PVI) is a standard treatment. Still, recurrence remains due to triggers outside the pulmonary veins (PVs).  

Researchers conducted a retrospective study to explore the relationship between embryologically classified AF triggers, clinical and genetic factors, and postablation prognosis.  

They analyzed data from 3,067 patients with AF who underwent PVI (cohort 1) and genetic analysis of AF-associated single-nucleotide polymorphisms (SNPs) in 815 patients (cohort 2), AF triggers were categorized by embryological origin: standard PV, sinus venosus (SV), and primitive atrium (PA).  

The results showed that SV-origin extra-PV AF triggers occurred in 20.3% (n = 622) of patients, while PA-origin triggers were found in 11.9% (n = 365) of patients (cohort 1). Multivariate analysis of cohort 2 revealed that female sex, lower body mass index (BMI), absence of hypertension, rs2634073 near PITX2, and rs6584555 in NEURL1 were associated with SV-origin AF, while nonparoxysmal AF and rs2634073 near PITX2 were predictors of PA-origin AF. The PA group showed a significantly higher rate of arrhythmia recurrence after repeated procedures compared to the standard PV (HR: 1.75; 95% CI: 1.34-2.29; P<0.001) and SV-AF (HR: 1.31; 95% CI: 1.19-1.45; P<0.001) groups, AEs rates were similar among all 3 groups.  

They concluded that SV-derived AF triggers might have a favorable postablation prognosis, while PA-derived triggers were linked to persistent AF and poorer response to ablation.  

Source: jacc.org/doi/abs/10.1016/j.jacc.2024.08.060