Point-of-Care ultrasonography can help differentiate cardiac from pulmonary causes of dyspnea. This study found that inferior vena cava B-mode diameter during inspiration of greater than 9 mm predicted dyspnea of cardiac origin with a sensitivity of 84.4% and a specificity of 92.9% (Am J Emerg Med. 2014 Dec 26. pii: S0735-6757(14)00934-6.)Read More