The person has no left atrial appendage by nature: a rare anatomical cardiac condition

Excerpt

An 82-year-old female elected to undergo catheter ablation for symptomatic persistent atrial fibrillation (AF). Before the procedure, we performed transoesophageal echocardiography to evaluate cardiac thrombus in the left atrial appendage (LAA) but could not detect the LAA itself (Fig. 1A). To evaluate the details of cardiac anatomy, a cardiac computed tomography (CT) was performed. The CT showed normal left- and right-sided pulmonary veins (LPV and RPV), but no evidence of the LAA despite no history of cardiac surgery (Fig. 1B). These findings suggested that she had no LAA by nature. Three-dimensional CT reconstruction of the right and left atrium (RA and LA) using an electroanatomic mapping system (CARTO 3, Biosense Webster, Diamond Bar, CA, USA) clearly revealed the absence of the LAA (Fig. 1C). The area where the LAA normally exists was covered with atrial muscles (Inner view). We were able to record bipolar voltages from these areas similar to other areas of the LA (LA voltage map). However, the causal relationship between AF and these potentials was uncertain in this case. The PV isolation by radiofrequency catheter ablation was completed without any complications. The biggest question, in this case, was whether anticoagulants should be continued. At present, there is no right answer because of the rarity of this condition. Although the risk of cardioembolic stroke may be low in AF patients without LAA, we decided to continue the anticoagulants because her CHA₂DS₂-VASc score was high.

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