Figure 1From: Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency settingFlow diagram illustrating recruitment, exclusion and subsequent grouping of all patients in the study. NT-proBNP, N-terminal pro-brain natriuretic peptide.Back to article page