82F POD 7 for right dyanmic hip screw for a right hip fracture developed acute hypotension who was not hypoxic with normal breath sounds.  JVP was not visible due to obesity.  She was afebrile with cool extremties.

36F presented with acute respiratory distress who was found to be in shock and severely hypoxic with normal thoracic auscultatory findings though heart sounds were masked by her breath sounds.  The JVP was grossly distended with no leg edema.

78F with CKD (baseline Cr 180s) who was very sedentary due to severe osteoarthritis presented with two weeks of dyspnea associated with presyncope who was found to be hypoxic and hypotensive.   V/Q was not available.

53M presented with atypical retrosternal chest pain and progressive presyncope two weeks after pulmonary vein isolation for atrial fibrillation who was found to be very uncomfortable due chest discomfort.  He was not hypoxic and blood pressure was within normal limits.  ECG demonstrated no ischemic findings except for significantly reduced voltages.

68F with severe peripheral vascular disease (no rest pain at baseline), hypertension, chronic renal failure, and systolic heart failure with biventricular hypokinesis with LVEF ~30% and mild mitral regurgitation (ECHO ~2 years prior to presentation) presented with ~1 week history resting bilateral leg pain associated with pallor and coldness.  Doppler found the presence of bilateral tibial posterial arteries' pulsation - albeit faint.  Her BP was 124/73 (previous documented readings SBPs 160s, DBPs 90s).  She was tachypnic and required 4L oxygen.  However, she was not in respiratory distress.  ECG revealed no ischemic changes.

87M with known moderate aortic and mild mitral stenosis and presevered LVEF characterized by an echocardiogram from 4 years prior and RV pacer for type II secondary degree heart block presented with subacute SOBOE - NYHA II to IV - and presyncope who was found to be hypotensive yet not hypoxic.  Lung fields was clear to auscultation.  No signs suggestive of severe aortic stenosis was found on physical exam.  His extremities were cold.  Lactate and Cr were both elevated with, and the ECG demonstrated sinus rhythm with no ischemic changes.