Discussion
Pre-operative evaluation for PVI is usually performed using TOE or CT to assess LA/LAA and the surrounding anatomy and thrombus1. TOE is mostly used in our institute; however, it is time-consuming and may sometimes induce discomfort and cause complications, and in the era of COVID-19, the indication has been revised to prevent the spread of the virus. Cardiac CT is a reliable alternative tool but has certain limitations in differentiating thrombi from low blood flow and may cause serious kidney problems.
ICE is an emerging alternative for LAA assessment for patients undergoing PVI and has similar diagnostic efficacy for LAA thrombus2. We practically use intra-operative ICE for AF patients with low CHADS2-Vask score ≤1: we carefully evaluate LAA from right atrium and right ventricular outflow with ICE before the puncture of atrial septum. The present patient had a score of 1 due to sex alone and underwent intra-operative ICE, which revealed a small LA myxoma attached to the atrial septum. A previous study reported that TTE shows a high detection rate of cardiac myxoma similar to TEE3, however, the present myxoma developing in the LA near the fossa ovalis, the most frequent site of origin, could not be found by TTE pre-operatively and even when we carefully examined the images post-operatively. The presence of LA myxoma is an absolute contraindication for PVI and the procedure was stopped before the transseptal puncture.
Intra-procedural ICE is a reliable imaging modality when the primary aim is to exclude LA/LAA thrombus but is unsuitable for evaluating unusual and unexpected cardiac structures, which pre-procedural TEE or CT can identify. Imaging options should be further discussed to improve patient care and safety.