Persistent Atrial Fibrillation Related to a Congenital Pericardial Defect and Left Atrial Appendage Herniation

Abstract

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.

Surgical correction of left auricular aneurysm herniation through a pericardial defect in a dog with atrial fibrillation and mitral valve disease

“…In the present case, as the atrial fibrillation permanently reverted after re‐position of the herniated left auricle without anti‐arrhythmic drugs, a mechanical cause of the atrial fibrillation was suspected. The same outcome of resolution of atrial fibrillation following auriculectomy of a herniated atrial appendage has also been described in humans 15,18,27,35,36 . Although syncope episodes can be secondary to atrial fibrillation, in the case reported here, syncope was present before the development of arrhythmias, possibly resulting from vasovagal stimulation by the herniated left auricle, although other causes, such as atrial paroxysmal tachycardia, could not be ruled out 3,40 .…”

“…The same outcome of resolution of atrial fibrillation following auriculectomy of a herniated atrial appendage has also been described in humans. 15,18,27,35,36 Although syncope episodes can be secondary to atrial fibrillation, in the case reported here, syncope was present before the development of arrhythmias, possibly resulting from vasovagal stimulation by the herniated left auricle, although other causes, such as atrial paroxysmal tachycardia, could not be ruled out. 3,40 In humans, syncope associated with auricular herniation has been suspected to result from stimulation of the atrial baroreceptors by the sliding of the herniated appendage causing vagal bradycardia or hypotension.…”

“…In the human literature, most authors recommend surgical treatment for partial pericardial defects, particularly if patients are symptomatic and potential risk for cardiac herniation is detected 13,19,25,26 . When auricular herniation and aneurysm are diagnosed, surgical excision of the appendage has been successful in eliminating both atrial arrhythmias and thromboemboli, and in resolving clinical signs 15,18,19,27 . A recent case in the veterinary literature describes successful auriculectomy of a left auricular aneurysm in a dog 28 .…”

“…9,10 Although it is believed that most humans and dogs with pericardial defects are asymptomatic, some of the clinical signs reported are chest pain, fatigue, syncope, supraventricular arrhythmias and sudden death. 2,3,5,6,[11][12][13][14][15][16][17][18][19][20][21][22][23][24] Complete absence of the pericardium or large defects are more likely to be asymptomatic or cause signs that do not require surgical treatment; however, oval defects with herniation (abnormal migration of a structure through an opening) ± aneurysm (ballooning of a structure), strangulation or incarceration of cardiac chambers are presumed to be responsible for the most severe and potentially life-threatening clinical signs. All cases of confirmed pericardial defects with right or left auricular herniation reported in the veterinary literature presented with supraventricular arrhythmias; either atrial fibrillation 2,5,6 or atrial premature complexes with runs of atrial tachycardia.…”

Case series, contemporary review and imaging guided diagnostic and management approach of congenital pericardial defects

“…The risk of sudden death in this scenario was attributed to the herniation of the LV or atrial appendage (AA) and involvement of the left circumflex coronary artery 21. Left AA protrusion might also cause persistent atrial fibrillation 22. Left-sided pneumothorax with consequent protrusion of the heart into left thoracic cavity was also described 23.…”