24 Feb - Syncope, MI, and LBBB

     Todays case was a patient with a significant underlying seizure history (poorly controlled) who now presents with several episodes of loss of consciousness not associated with convulsions.  Echocardiography revealed a rare congenital malformation - cor triatriatum.  This was likely unrelated to the syncopal event.  It is condition where atrium is divided into two chambers by a septum, which can produce symptoms the functional equivalent of mitral stenosis.
     A brief case discussion focused on patients with chest pain and left bundle branch block.  Symptoms suggestive of cardiac ischemia with a new or unknown duration LBBB should be managed as ST elevation MIs.  In patients with old LBBB and chest pain, some features suggest the presence of MI:  1mm concordant ST elevation, 5mm discordant ST elevation, or 1mm ST depression in leads V1, V2, or V3.  This data came from a substudy of the landmark GUSTO trial that established the usefulness of TPA for treatment of acute MI.  You can expect a question about MI in setting of LBBB on boards.