Discussion
Incidence of left atrial dissection is low and is reported to be 0.16% following mitral valve surgery and 0.02% following coronary artery bypass grafting . This condition is being increasingly recognized following surgery because of increased use of TEE since 1990. Left atrial dissection following PCI is less common and literature search is limited to sporadic case reports, it is only after 2000 that case reports of LatD as a complication of percutaneous procedures started appearing in literature
Left atrial dissection has a variable clinical course. Cases described have ranged from self-limiting stable disease to lethal outcomes. Mortality rate of up to 13.8% has been described in surgical literature. Left atrial dissection presents immediately and majority of the cases, though it has been reported to occur months or even years after the procedure. Dyspnea is the commonest presenting symptom and present in about a quarter of the patients. Chest pain and arrhythmias have been reported, about 10% of the patients are asymptomatic.
Our case was readily recognized by transthoracic echocardiography. Duplication of left atrial free wall is the most common abnormality seen on echocardiography . Left atrial dissection, especially if there is thrombus in the false lumen, can mimic left atrial mass. Cardiac tamponade, hiatal hernia, plueropericardial cysts causing extrinsic compression of the left atrium can also mimic left atrial dissection.Multimodality imaging has been recommended to confirm diagnosis of this rare condition. In our case CT scanning coupled with TTE corroborated the diagnosis.
Pathogenesis of left atrial dissection is varied. Majority of the cases arise from injury along the AV junction which results in separation of the endocardium of the left atrium causing the dissection cavity. Other entry points are also possible and likely explain LatD arising from aortic valve replacement, percutaneous coronary interventions and pulmonary vein cannulation Similar to the cases reported by Solzbach and Cresce et al, we too believe that a distal perforation from guide wire manipulation resulted in left atrial injury.
Indication for surgery should be based on clinical presentation. in patients with hemodynamic instability prompt surgical approach is warranted. Surgical technique involves obliteration of the false cavity and addressing the entry point if possible. Medical management or non-operative approach, supported by serial imaging is reasonable in a stable patient. Reversal of anticoagulation when feasible should also be considered.
List of figures:
Figure 1: LA dissection 2C view (arrow)
Figure 2: LA dissection 4C view (arrow)
Figure 3: LA filled with thrombus (star)
Figure 4: LA thrombus with active leak (arrow)