Characteristics and Ablation Outcomes of Atrial Tachycardia in Patients with Prior Cardiac Surgery vs. Spontaneous Scars: Where Are the Differences?

Abstract

(1) Background: Atrial scars play an important role in atrial tachycardia (AT). They can not only be found in patients with prior cardiac surgery (PCS) but also in patients without PCS or significant structural heart disease, in which case the scar is called a spontaneous scar (SS). This study aims to compare the characteristics, mechanisms and ablation outcomes of AT in patients with PCS and SS. (2) Methods: We retrospectively reviewed electrophysiological and ablative characteristics of ATs in 46 patients with PCS and 18 patients with SS. (3) Results: There were averages of 1.52 and 2.33 ATs per patient in the PCS group and SS group, respectively (p < 0.01). Cavo-tricuspid isthmus dependent atrial flutter (CTI-AFL) was presented in most patients in both groups (93.50% vs. 77.80%, p = 0.17), whereas the SS group had a higher occurrence of scar-mediated reentrant AT (SMAT) and focal AT (FAT) compared with the PCS group (88.90% vs. 39.10%, p < 0.01; 22.2% vs. 2.2%, p < 0.05). There were no significant differences in acute success rate between the two groups, whereas patients with SS had lower long-term success rate (87.0% vs. 61.1%, p < 0.05) and higher occurrence of sinus node dysfunction (SND) (4.3% vs. 22.2%, p < 0.05). (4) Conclusions: CTI-AFL is common in both patients with PCS and SS, and routine CTI ablation is recommended. Compared with patients with PCS, patients with SS have more ATs, especially with higher occurrence of SMAT and FAT, and had a lower long-term success rate and higher incidence of SND.

Use of a lumenless bipolar lead in the right atrial septum in a patient with extensive right atrial scar

“…After ablation, long-term follow-up revealed 5 out of the 8 patients developed sinus node dysfunction and required permanent pacing. Wang and colleagues 3 found more sinus node dysfunction in patients with spontaneous scar vs those with a history of prior cardiac surgery. The spontaneous scar along with ablation of the RA macroreentrant tachycardia caused an “atrial compartmentation” leading to sinus node dysfunction and atrial standstill.…”

Impact of Low Voltage Threshold Adjustment on Activation Mapping Interpretation for Atrial Tachycardia in Low-Voltage Left Atrium

“…In these cases these mapping points may hold vital information for the accurate diagnosis of AT mechanism [ 7 , 8 , 9 ]. However, due to their extremely low voltage, these points may be hard to distinguish from background noise (BGN), leading to their exclusion from activation mapping [ 4 , 8 , 10 ]. But if BGN suppression is satisfactory, the accuracy of mapping results could be enhanced by including these low-voltage points.…”