Rapid and dynamic changes of N-terminal proB-type natriuretic peptide (NT-proBNP) in a patient during paroxysmal atrial fibrillation (PAF).

N-terminal proB-type natriuretic peptide (NT-proBNP) is known as a marker of heart failure (HF). NT-proBNP is also elevated in a patient with atrial fibrillation (AF). In this case report, serial assays of NT-proBNP were performed in AF attack without HF. We found the positive association between the level of NT-proBNP and duration of AF attack. This case suggested that secretion of NT-proBNP from left atrium might be abundant in the case of paroxysmal AF (PAF) or PAF might lead to increasing left ventricle stress in a time-dependent manner. Moreover, it is suggested that the measurement of NT-proBNP levels considering the elapsed time after the onset of PAF would be useful. <Learning objective: Measurement of NT-proBNP levels during PAF attack may be useful to estimate the duration of PAF attack and degree of left ventricle stress in patients with PAF.>.