congenital pericardial defects ( cpds ) are uncommon anomalies that are usually discovered unexpectedly by a cardiologist , radiologist , or surgeon .
occasionally , these defects may cause symptoms such as chest pain , dyspnea , arrhythmias , syncope , and even sudden death .
arrhythmias , including atrial fibrillation ( af ) , are uncommonly found in cases of cpd .
herein , we report the case of a patient with persistent af associated with a cpd and herniation of an enlarged left atrial ( la ) appendage .
the patient was treated successfully with a hybrid procedure , in which total thoracoscopic ablation ( tta ) was followed by an electrophysiological ( ep ) study .
his medical history was otherwise unremarkable , except for a history of hypothyroidism diagnosed eight years previously . a hybrid procedure involving tta followed by an ep study
preoperative computed tomography ( ct ) and echocardiography showed no evidence of thrombi or vegetation with la enlargement .
the size and volume index of the la were 55 mm and 69.4 ml / m , respectively .
tta was performed under general anesthesia with double - lumen intubation . on the right side , a larger than normal atrium
a large pericardial defect was found , through which an enlarged la appendage was herniated ( fig .
1b ) . although handling the lighted dissector ( atricure lumitip dissector ; atricure inc . ,
cincinnati , oh , usa ) was difficult due to the large mobile la appendage , pulmonary vein isolation and additional superior and inferior line ablation were successfully completed , and the la appendage was resected with an endoscopic stapler .
an episode of af occurred on the fourth postoperative day , and the patient was converted to sinus conversion through cardioversion .
a follow - up ep study on the eleventh postoperative day revealed successful pulmonary vein isolation , and cavotricuspid isthmus ablation was performed .
left - side defects are most common , accounting for approximately 70% of cases , followed by right - side defects ( 17% ) and complete defects ( 9% ) .
although patients are usually asymptomatic and most cpds are discovered incidentally , patients with partial defects may present with acute symptoms such as chest pain , dyspnea , arrhythmia , syncope , and even sudden death due to strangulation of the herniated cardiac chamber .
echocardiography and ct are the most common methods used to evaluate cardiac and thoracic abnormalities ; however , pericardial defects may go unrecognized for years , as in this case .
magnetic resonance imaging ( mri ) has been reported to be superior to echocardiography , but cardiac mri is still only applicable to a limited set of lesions .
furthermore , enlargement of the la and la appendages due to herniation , as in our patient , may contribute to the development of persistent af , and may even be its cause .
several methods have been proposed for the treatment of cpd , including la appendectomy , extension of the pericardium to reduce incarceration , primary closure , and patch closure using synthetic materials .
however , no consensus currently exists regarding therapeutic options for cpd due to the small number of cases .
although a previous case of paroxysmal af was resolved via resection of the la appendage instead of antiarrhythmic interventions , in cases of persistent af with an enlarged chamber , as in our patient , antiarrhythmic management techniques such as tta are probably necessary .
however , it involves complex techniques and invasive procedures , requiring median sternotomy and cardiopulmonary bypass [ 1012 ] .
accordingly , some researchers have recently suggested that minimally invasive thoracoscopic ablation be used , and hybrid tta has shown excellent results with low morbidity rates [ 1315 ] . in our patient ,
the hybrid tta procedure was initially planned for his persistent af , and the cpd was an incidental finding .
although the visual field was disturbed by the enlarged la appendage , the entire ablation procedure was successfully performed and the la appendage was resected safely . in conclusion , cpd is a possible incidental finding when performing cardiac operations , including tta
. enlarged la and la appendages due to herniation through the defect may cause persistent af , and antiarrhythmic treatment may be necessary for such patients .
tta can be successfully performed in patients with persistent af associated with a cpd and herniation of the enlarged la and/or an la appendage .
 congenital pericardial defects ( cpds ) are infrequent anomalies that are usually asymptomatic and are discovered incidentally during unrelated interventions . 
 here we report the case of a cpd with herniation of an enlarged left atrial appendage identified during total thoracoscopic ablation ( tta ) for persistent atrial fibrillation ( af ) . 
 the persistent af was successfully treated with a hybrid procedure , in which tta was followed by an electrophysiological study . 
CASE REPORT
DISCUSSION