Abstract
Funding Acknowledgements
CVON-AFFIP (914728), NWO-Vidi (91717339), Biosense Webster USA (ICD 783454) and Medical Delta.
Background
At present, it is unknown if intra-atrial conduction during sinus rhythm (SR) is influenced by prior atrial fibrillation (AF) episodes or by various underlying heart diseases (UHD). However, it is considered that structural and electrical remodeled atria contain more conduction abnormalities and prolonged conduction times (CTs).
Purpose
To determine the impact of AF episodes on conduction abnormalities and to distinguish conduction abnormalities between patients with ischemic heart disease (IHD), (ischemic and) valvular heart disease ((i)VHD) and congenital heart disease (CHD) by performing intraoperative high-resolution epicardial mapping.
Methods
The study population consists of 447 participants (325 male, age: 67.2 (58.9 – 73.1) years) with or without an history of AF (resp. N = 375 vs. N = 75) undergoing elective open heart surgery for either IHD (N = 238), (i)VHD (N = 169) or CHD (N = 40). High-resolution epicardial mapping of the right atrium (RA), Bachmann’s Bundle (BB), left atrium (LA) and pulmonary vein area (PVA) was performed during SR using a unipolar 128/192-electrode array (interelectrode distance: 2mm). Inter-electrode CTs (Δ local activation time between two adjacent electrodes) were quantified as the relative frequency distribution of CTs, cumulative incidence of CTs per patient (%) and the severity of CTs (%).
Results
Prior AF episodes were associated with prolongation of CTs (p < 0.05). Patients with AF had a higher cumulative incidence of CTs ≥4ms throughout both atria, with a predilection site at BB and LA (p < 0.05).
In the RA, conduction delays ≥48 ms were more present in patients with AF (44.0% versus 30.7%, p = 0.03), whereas in BB patients with AF already had more prolonged conduction delays ³16 ms (91.8% versus 81.2%, p = 0.03).
The relative frequency distribution of CTs did not differ between IHD, (i)VHD and CHD. Differences in the cumulative incidence of CTs between the three UHD were solely found at BB; patients with (i)VHD more frequently had incidence of CTs ³6ms than patients with IHD (p < 0.017).
However, conduction delays were more pronounced in patients with CHD (≈≥30 – ≥84 ms) and with (i)VHD (≥72 – ≥84 ms)(p < 0.017). Also, more patients with (i)VHD had prolonged conduction delays (≥24 – ≥34 ms) than patients with IHD (p < 0.017).
Conclusions
Patients with AF had more and severer conduction abnormalities than patients without AF. Comparing the three UHD, mainly BB was affected by conduction abnormalities. (i)VHD was associated with more conduction abnormalities than IHD. Most severe conduction abnormalities were found in patients with CHD compared to both patients with IHD and (i)VHD. These findings indicate that the arrhythmogenic substrate is affected most by prior AF episodes, (i)VHD and CHD, and particularly present at BB.
Fragmented Rockfall Volume Distribution from Photogrammetry-Based Structural Mapping and Discrete Fracture Networks
