NPPB and systemic lupus erythematosus: Similarly, discordantly low BNP levels upon admission have been observed in conditions such as flash pulmonary edema, acute pulmonary edema secondary to papillary muscle rupture, right ventricular myocarditis secondary to systemic lupus erythematosus, and intermediate high-risk pulmonary embolism, all of which present with an acute onset of less than 2 h (13).