AF induces more than 15 % of cerebral ischemic stroke [4–6]. For prevention of thromboembolic events in AF, anticoagulant therapy is one of the effective methods. Although warfarin is proved to be effective, there are some critical problems such as narrow therapeutic profile, multiple medication and food integration, and worsening bleeding disease [7]. Novel oral anticoagulants (NOAC) are also effective for preventing the stroke. For the patient who cannot keep the target range of INR by warfarin, NOAC will be an alternative. But it’s still controversial if NOAC therapy is safe for patients with bleeding complication, even with INR below therapeutic threshold.

On the other hand, LAA is the site where most of thromboembolism come from, so mechanical approaches to close the LAA both surgically and percutaneously were developed [8–13].

Complications during percutaneous LAA closure include vascular complications, periprocedural stroke, LA or LAA perforation, dislocation of the device, post-procedural mitral regurgitation, and peridevice leakage. According to PROTECT-AF trial, the reported incidence of serious pericardial effusions (defined as the need for percutaneous or surgical drainage) during LAA closure is 4.8 % [1]. LAA perforation during LAA closure procedure can be caused by introducer or closure device itself. It is usually difficult to recognize LAA perforation because the perforating sheath becomes a plug of the perforated hole. With a little bit of pullback of the perforating sheath, the hole becomes visible. The most important thing is that a pigtail catheter should be used when advancing the 14-Fr introducer. Set the pigtail catheter a little bit outside the 14-Fr introducer that should prevent as much as possible the edge of the introducer from touching LAA wall directly. Advancement must be done gently as much as possible to avoid the damage of LAA wall.

In the case described, we advanced the 14-Fr introducer with pigtail catheter very gently. Nevertheless, LAA perforation occurred, since LAA wall is very thin and LAA perforation during this procedure might be ineluctable complication. If perforation occurs during LAA closure procedure and it is immediately recognized, first of all, the LAA closure device should be deployed immediately. After that, left atrium angiography, TTE, or TEE should be performed in order to check pericardial effusion and needle pericardiocentesis if needed. Reverse of heparin effect by protamine administration should be considered after measurement of activated clotting time. If bleeding into the pericardial space persists, surgical repair is the remaining option.