Discussion
The case illustrates that posterior atrial wall perforation can be carried out in a conservative manner, without immediate subxiphoid access. Despite infusion of heparin and ACT greater than 300 seconds, all stages of ablation were performed without evidence of bleeding in the pericardial space. However, negative pressure was maintained by JR 6F catheter throughout the procedure.
Fisher et al. were the first to describe the possible management of hemopericardium in 2 patients in whom a long sheath was inadvertently positioned in the pericardial space, using the sheath itself to draw blood without the need for subxiphoid puncture(8).
Our group previously reported 2 cases in which, similarly, perforation in the posterior wall was identified and the ablation performed with isolation of the 4 pulmonary veins(9). In both cases only a small amount of blood was identified in the pericardial space. However, the operator opted to perform subxiphoid puncture at the end of the procedure with maintenance of negative pressure in the pericardial space through this access after the removal of the transseptal sheath from the pericardial space. The feasibility of the transatrial access was then demonstrated in a swine model(10).
To the best of our knowledge, this is the first case in which, despite the atrial perforation with the placement of the sheath within the pericardial space, no hemopericardium occurred and no subxiphoid puncture was performed. Our hypothesis is that the bleeding did not occur because the sheath itself, once positioned in the pericardial space, worked like a plug, preventing bleeding despite heparin infusion. Another hypothesis is that the maintenance of negative pressure throughout the procedure might facilitate the adhesion of the parietal to the visceral pericardium, which avoided further bleeding after sheath removal.