A 58-year-old male patient with a history of highly symptomatic paroxysmal atrial fibrillation (AF) and documented concomitant atrial flutter (AFL), hypertension, and obesity was scheduled for cryoballoon ablation (CB). Six months earlier he had undergone a cavotricuspid isthmus ablation (CTI) in a different center. At that time, he was originally scheduled for AF ablation, but the operator was discouraged from transseptal puncture due to a linear structure of an unknown origin diagnosed in the left atrium during pre-procedural 2D transesophageal echocardiography (TEE).
Transthoracic echocardiography (TTE) performed in our center showed normal left ventricular ejection fraction (LVEF, 60%), mildly dilated left atrium (LA area, 22 cm2), functionally bicuspid aortic valve with moderate stenosis (aortic valve area 1.1–1.2 cm2, gradient 36/16 mm Hg), and mild regurgitation. On the day of the procedure, the patient had sinus rhythm. A 3D TEE (Philips Epiq 7, Bothell, WA, US) performed in the cath lab showed a benign form of cor triatriatum sinister. A membrane located between the interatrial septum and the ridge between the left atrial appendage and left superior pulmonary vein with a significant opening in the middle was found, partially dividing the cavity of the LA into a posterosuperior part containing the ostia of the pulmonary veins and an anteroinferior part that provided the actual mitral inflow (Figure 1A and B, Supplementary materials, Video S1 and S2). A TEE-guided transseptal puncture was performed aiming at the pulmonary vein compartment of the LA (Figure 1C–F, Supplementary material, Video S3), and CB of AF was safely performed (Supplementary materials, Table S1, Figure S1). The patient was discharged the next day without complications.
Cor triatriatum is an extremely rare heart defect comprising less than 0.4% of all congenital heart diseases [1]. The symptoms depend on the connection between both LA compartments. Usually, mitral inflow is severely obstructed, and patients require surgery as infants. However, sometimes there is a wide opening in the membrane, and patients remain asymptomatic for many years and may get diagnosed accidentally as in our case. According to Karimianopur et al. [2] such a phenomenon takes place in one in thousand AF ablations.
CB is a well-recognized and widely utilized procedure for AF ablation in Poland [3]. It has been demonstrated that this single-shot ablation was feasible and safe to perform in patients with anatomical variabilities of the LA [4]. The important role of 3D TEE in interventional cardiology has also been previously reported [5].
We would like to emphasize that in this case, 3D/2D TEE allowed for proper diagnosis and safe pulmonary vein isolation using a cryoballoon in a patient with a benign form of triatrial heart without the need for other preprocedural cardiac imaging including contrast-enhanced computed tomography.
Supplementary material
Supplementary material is available at https://journals.viamedica.pl/kardiologia_polska.
Article information
Conflict of interest: MMF and MP received speaker/proctoring fees from Medtronic Poland. Other authors declare no conflict of interest.
Funding: None.
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