Predictors of iatrogenic atrial septal defects: analysis of fibrotic atrial cardiomyopathy, valvular disease, and transseptal sheath size

Abstract

Background: Transseptal puncture (TSP) for left atrial access is routinely used during various cardiac interventions, including ablation for atrial tachyarrhythmia. However, in selected patients, subsequent iatrogenic atrial septal defects (iASD) persist. This study determines whether fibrotic atrial cardiomyopathy (FACM) or mitral valve regurgitation (MR) are predictors of persistent iASD development post-TSP.

Methods: We analyzed data from patients undergoing radiofrequency ablation with high-density electroanatomical mapping for recurrent atrial tachyarrhythmias after a primary pulmonary vein isolation using either cryo or RF technologies. Patients were categorized based on transesophageal echocardiography findings: (1) competent atrial septum (cAS) (2), iASD, or (3) a patent foramen ovale (PFO). Differences in FACM and MR were assessed across these groups.

Results: Of 149 patients (age 67.7 ± 9.7 years), 125 (83.9%) had cAS, 8 (5.4%) iASD, and 16 (10.7%) PFO. No significant differences were observed in age (p = 0.932), BMI (p = 0.612), or LVEF (p = 0.581). The TSP sheath size was not associated with iASD occurrence (p = 0.857). Common surrogates of FACM, i.e., LAVI (p = 0.114), LA area (p = 0.156), mean left atrial pressure (LAP; p = 0.459), or total low-voltage area burden (p = 0.058) did not differ significantly among groups. MR was not linked to increased LAP (at first (p = 0.290) and second procedure (p = 0.212)) or a higher incidence of iASD (at first (p = 0.155) and second procedure (p = 0.917)). Mean LAP did not correlate with LA size (p = 0.471) or low-voltage extent (p = 0.084).

Conclusion: Our findings underscore that iASDs post-TSP for left atrial ablation are uncommon and unrelated to TSP sheath size, FACM, or MR, further minimizing concerns for routine interventions in patients with more advanced arrhythmia substrate or valvular disease.

Keywords: Ablation; Atrial cardiomyopathy; Atrial fibrillation; Atrial septal defect; Transseptal puncture.

Fig. 1

Study cohort. a Measurements during the 2nd procedure and significance levels for variations between groups. BMI Body Mass Index, LVEF Left Ventricular Ejection Fraction, TAPSE Tricuspid Annular Plane Systolic Excursion, LAVI Left Atrial Volume Index, LA Area Left Atrial Planimetric Area, LVA Extent Low Voltage Area Extent, LAP Mean Left Atrial Pressure. b Transseptal left atrial access during the first procedure and the associated incidence of iASD c Example TEE of an iatrogenic atrial septal defect. LA Left Atrium RA Right Atrium AV Aortic Valve. d Distribution of patients with left-to-right shunt and iatrogenic atrial septal defects or patent foramen ovale. e Age, LVEF, LAVI, and LVA extent in the cohort during the 2nd procedure

Fig. 2

Iatrogenic Atrial Septal Defects in Fibrotic Atrial Cardiomyopathy. a CARTO Map example as used for determining LA low-voltage. b Distribution of low-voltage area burden in patients with competent atrial septum (cAS), iatrogenic atrial septal defects (iASD), and patent foramen ovale (PFO). c Left Ventricular Ejection Fraction across patients with cAS, iASD, and PFO. d Left Atrial Volume Index across patients with cAS, iASD, and PFO. e Mean Left Atrial Pressure across patients with cAS, iASD, and PFO

Fig. 3

Iatrogenic Atrial Septal Defects in Mitral Valve Regurgitation. a TEE findings of moderate mitral valve regurgitation. b Distribution of Left Ventricular Ejection Fraction (LVEF), Left Atrial Planimetric Area (Left Atrial Area), and Mean Left Atrial Pressure at the first and second procedures across varying degrees of mitral valve regurgitation. c Distribution of septal competence across different levels of mitral valve insufficiency. d MR levels for competent atrial septum (cAS) and iatrogenic atrial septal defects (iASD) at first and second procedure