AHF patients defined as: an unplanned emergency department visit or hospitalization for AHF, dyspnea at rest that had worsened during the previous week, evidence of HF on chest radiography, a blood BNP level of more than 500 pg per milliliter, or an NT-proBNP level of more than 2000 pg per milliliter. All patients that continued to have dyspnea at rest for at least 2 h after IV furosemide at a dose of 40 mg (or equivalent) with sBP between 116–180 mmHg. Here, NPPB is linked to hydrops fetalis.