Your patient is a 53 y/o male who complains of sudden onset dyspnea, fatigue and weakness.  BP-100/66, P-92 and irregular.  The cardiac monitor indicates atrial fibrillation at a rate of 184.  Skin is pale and moist.  You hear basal rales bilaterally and note JVD.  He has a hx of paroxysmal atrial fibrillation.  There is no other medical history.  What are your concerns for this patient?  What treatment would likely be indicated?