Advanced mapping strategies for ablation therapy in adults with congenital heart disease

Abstract

Background: Ultra-high density mapping (HDM) is a promising tool in the treatment of patients with complex arrhythmias. In adults with congenital heart disease (CHD), rhythm disorders are among the most common complications but catheter ablation can be challenging due to heterogenous anatomy and complex arrhythmogenic substrates. Here, we describe our initial experience using HDM in conjunction with novel automated annotation algorithms in patients with moderate to great CHD complexity.Methods: We studied a series of consecutive adult patients with moderate to great CHD complexity and an indication for catheter ablation due to symptomatic arrhythmia. HDM was conducted using the Rhythmia™ mapping system and a 64-electrode mini-basket catheter for identification of anatomy, voltage, activation pattern and critical areas of arrhythmia for ablation guidance. To investigate novel advanced mapping strategies, postprocedural signal processing using the Lumipoint™ software was applied.Results: In 19 patients (53±3 years; 53% male), 21 consecutive ablation procedures were conducted.Procedures included ablation of atrial fibrillation (n=7; 33%), atrial tachycardia (n=11; 52%), atrioventricular accessory pathway (n=1; 5%), the atrioventricular node (n=1; 5%) and ventricular arrhythmias (n=4; 19%). A total of 23 supraventricular and 8 ventricular arrhythmias were studied with the generation of 56 complete high density maps (atrial n=43; ventricular n=11, coronary sinus n=2) and an average of 12,043±1,679 mapping points. Multiple arrhythmias were observed in n=7 procedures (33% of procedures; range of arrhythmias detected 2-4). A total range of 1-4 critical areas were defined per procedure and treated within a radiofrequency application time of 16 (interquartile range 12-45) minutes. Postprocedural signal processing using Lumipoint™ allowed rapid annotation of fractionated signals within specific windows of interest.This supported identification of a practical critical isthmus in 20 out of 27 completed atrial and ventricular tachycardia activation maps.Conclusions: Our findings suggest that HDM in conjunction with novel automated annotation algorithms provides detailed insights into arrhythmia mechanisms and might facilitate tailored catheter ablation in patients with moderate to great CHD complexity.

A novel algorithm for 3-D visualization of electrogram duration for substrate-mapping in patients with ischemic heart disease and ventricular tachycardia

“…For this, an expandable 64-polar mini basket catheter (Orion, Boston Scientific) comprising of eight splines with eight electrodes (electrode spacing 2.5 mm, electrode surface area 0.4 mm 2 ) was maneuvered into the left ventricle via an atrial transseptal puncture, using a fixed curve long sheath (SL0, 8-F; St. Jude Medical, USA; for the ablation catheter) and a long steerable sheath (Agilis large curl, 8.5-F, St. Jude Medical, for the mini basket catheter) [2]. Electrogram annotation was conducted automatically by the mapping system using the following criteria for beat acceptance: (1) cycle length stability: ±10 ms; (2) stability of relative timing of reference electrograms: ±5 ms; (3) respiration gating: automatic measurement and filtering of motion above maximum inspiration movement by change of impedance of the ECG-electrodes; (4) electrode location stability: 2-3 mm [12]. The maximum projection distance of the electrode to the captured anatomic geometry was set to 3 mm [13].…”

Targeted cluster ablation of non‐CTI‐dependent atrial arrhythmias in congenital heart disease using ultrahigh‐definition mapping

“…New substrates for recurrences were identified in repeat procedures to be mechanistically distinct, which have been reported in other CHD cohorts. 9,16,22 This finding would suggest that the index arrhythmia substrates were appropriately targeted in our cohort and that potentially they were the result of progressive atrial myopathy rather than inadequate ablation strategy or lesion formation.…”

Detection of an epicardial accessory pathway using the novel algorithm during ultra-high-density mapping

“…2 Several reports have been published on its usefulness for identifying the critical isthmus and abnormal diastolic potentials of ventricular tachycardia, atrial tachycardia, and APs, [3][4][5] and its safety and efficacy are proven in patients with congenital heart disease. 6 Rhythmia is also a very useful tool for finding the optimal ablation point for an AP by using dual-chamber mapping. 7 However, Lumipoint operates with a different algorithm than the conventional activation mapping algorithm.…”