NPPB and atrial fibrillation: With the purpose to determine the contribution of NT-proBNP to the selection of patients suitable for a successful cardioversion of AF with flecainide, Amin and coworkers carried out a prospective study under very specific clinical circumstances: symptomatic < 24 hours AF, neither structural heart disease, nor left ventricular ejection fraction < 55 %, nor severe comorbidity [3].