The second point is the high percentage of false-negative findings of cardiogenic edema (37%). The interstitial syndrome is nothing more than the ultrasound effect of a partial loss of aeration and increase in density, which involves the periphery of the lung. The sensitivity was very high in previous studies. If congestion occurs, B-lines should be bilateral, homogeneously distributed, and multiple in the anterior and lateral chest. In my opinion, there are only three possible explanations for false-negative findings. The first explanation is the effect of early treatment preceding LUS. B-lines have been shown to be very fast to appear but just as quick to resolve following medical and ventilator treatment.4 A second explanation is that congestion may spare the lung periphery. In this case, normally aerated lung interposes between the probe and the congested lung, thus giving a false-negative pattern. This would be contrary to physiology and the anatomic distribution of the secondary pulmonary lobules.5 The third explanation is respiratory distress not due to congestion in acute heart failure, which is a novelty worth consideration and full discussion.