DISCUSSION
Spontaneous left atrial intramural dissecting hematoma is exceedingly rare entity with unknown true incidence. Most of the information is available from isolated case reports. From aetiological perspective LAIH causes could be grouped into 4 major categories based on available published literature. Firstly, it can be secondary to complications of post cardiac surgeries like mitral and aortic valve replacement. Secondly it can be a result of iatrogenic complications secondary to percutaneous interventions (mainly due to high-risk coronary interventions, and during radiofrequency Cath ablation in electrophysiology lab [2-5]. Thirdly it has been reported to occur in conditions like amyloidosis, mitral annular calcification and/or annular abscess, blunt chest trauma and dissecting aortic aneurysms and lastly as in our case it can be spontaneous[6-9]. Usually LAIH has predilection to posterior LA wall (81%) due to lower quantity of fibrous tissue; however, in our case it occupied the whole of left atrium. Our patient posed a diagnostic dilemma as he did not have any predisposing factors and closely mimicked acute coronary syndrome (ACS)/pericarditis at presentation which mandated coronary angiogram. Retrospectively we thought that PR segment depression on presentation EKG could be secondary to atrial ischemia rather than ACS/pericarditis though there was no PR segment elevation. The pathological report did show necrosis of underlying LA endocardium. We used unfractionated heparin for ACS treatment initially which could be hypothesized to cause cystic degeneration of LA intramural thrombus. There is a close overlap between left atrial dissection and LAIH. The former is thought to originate from contained atrioventricular separation allowing pressurised blood flow from left ventricle to dissect the layers of posterior LA. In our case surgeons observed separation of endocardium and epicardium in posterior LA wall, henceforth it might be appropriate to term this LA mass as spontaneous intramural multiseptated dissecting hematoma. There are no definitive guidelines for management with some cases having predisposing factors being observed conservatively and majority of the cases went to operating theatre, as they were symptomatic. The work up of LAIH starts from imaging as clinical and laboratory parameters are mostly variable and misleading.