Right-sided Atrial Flutter Ablation after Tricuspid Valve-in-Valve Replacement

A 49-year-old patient presented to the outpatient clinic with palpitations, dizziness and exercise intolerance for about two months and was found to be in atrial flutter (fig. 1A). Recurrent flutter episodes were known for several years requiring repeated direct current cardioversions in the past as well as intermittent amiodarone treatment. His past medical history included bioprosthetic tricuspid valve (TV) replacement (Shelhigh 33mm) for severe tricuspid regurgitation due to endocarditis related to intravenous drug abuse at the age of 35. Thirteen years after, he was successfully treated with transcatheter tricuspid valve-in-valve replacement with an Edwards SAPIEN 3 (29 mm) valve due to severe bioprosthetic TV stenosis. His recent echocardiography revealed a normally functioning TV prosthesis with mildly reduced right ventricular function and normal right atrial (RA) size (fig. 1B). Due to symptomatic recurrent atrial flutter, we opted for catheter ablation.

Atrial arrhythmias are commonly seen in patients with tricuspid and mitral valve replacement. On the one hand this is a consequence of surgical incisions resulting in fibrosed areas of slow electrical conduction, but also occur secondary due to altered haemodynamics associated with the causative valvular pathology. The most common arrhythmias after TV surgery were found to be CTI dependent arrhythmias in a large cohort of adult congenital heart disease (ACHD) patients [1]. CTI ablation with radiofrequency energy is known to be a highly effective and safe procedure [2]. However, CTI ablation in patients after prosthetic TV replacement can be technically challenging due to a portion of the atrial myocardium participating in the reentry circuit potentially being covered by prosthetic material, thus remaining inaccessible for ablation [1]. Moreover, there is concern that the sewing ring near the annulus might generate an anatomical obstacle for linear ablation [3, 4]. However, several prior case reports have demonstrated successful CTI ablation in the presence of a prosthetic TV [3–7], highlighting their particular challenges. One case required subvalvular needle puncture to reach the protected myocardium below the bioprosthetic valve for successful ablation [7]. Another case study highlighted the importance of multimodal imaging to increase success and reduce complication rates [8]. These included preprocedural computed tomography imaging to assess the anatomical relationship between the prosthetic valve and the true atrioventricular annulus, intracardiac echocardiography to monitor catheter contact and stability combined with electroanatomical mapping and fluoroscopy. A larger case series of CTI ablation in ACHD patients with prosthetic TV or tricuspid annuloplasty ring demonstrated, that atrial tissue critical to the arrhythmia may require ablation from the ventricular side of the prosthesis without damage to the valve and good short-term outcomes [9]. In contrast to the case reports, the largest case series so far, involving several experienced ACHD centres systematically investigating the impact of TV surgery on catheter ablation outcomes, found, that catheter ablation success was lower and tachycardia recurrence was higher after TV ring/replacement surgery compared to patients without prior TV surgery or with TV repair only [1]. In addition, procedures after TV surgery were longer and required greater fluoroscopy exposure and energy delivery.