冠狀動脈婁管是罕見的冠狀動脈異常。這類患者通常沒症狀或只有輕微症狀，但較大的冠狀動脈婁管也可能導致心臟衰竭；這種情形就需要治療。除了外科手術外，線圈栓塞也是可接受的治療方式。線圈栓塞術可能引起的併發症包括線圈移位，血腫，導線傷害血管引起血管破裂，以及溶血。但這處置引發心臟傳導阻滯的案例，就沒有報告過。我們報告一位56歲男性，因嚴重呼吸困難而求診。起初認為是急性冠心症，但做心導管時發現一個源自冠狀動脈左迴旋支的婁管。對於這婁管，病患接受了線圈栓塞，但栓塞後發生了心臟傳導阻滯因此需要暫時性心率調節器治療。我們認為放置線圈時，婁管附近的小分支血流也可能受影響；若影響到房室結動脈，就可能造成心臟傳導阻滯。若將線圈放得更遠端些，應可以減少這種併發症。

Coronary artery fistulas are uncommon abnormalities. Large coronary artery fistulas may result in symptomatic heart failure and require treatment. Coil embolization is an acceptable alternative to surgery for patients with coronary fistula. Its complications include coil migration, hematoma, perforation of the vessel wall by the guidewires, and hemolysis. However, complete atrioventricular (AV) block induced by the procedure was not reported previously. We report a 56 year-old man, who suffered from severe dyspnea. Initially, acute coronary syndrome was suspected. A fistula originating from the left circumflex artery and drain into the coronary sinus was noted during cardiac catheterization. For the fistula, this patient underwent transcatheter embolization with coils. Complete AV block occurred just after embolization and temporary pacing was required. We proposed that coil embolization for coronary artery might influence the flow of normal branches near the fistula. If the AV nodal artery flow is compromised, heart block may develop. To deploy the coils more distally could decrease such complication.