NPPB and hydrops fetalis: No significant differences were found with regard to gender, age, causes of HF, NYHA classification, heart rate, QRS duration, serum creatinine level, NT-proBNP level, echocardiographic indices (LVEDVI, LVESVI, LVEF, E, A, Sm, Em and Am), medication regimen or LV lead position between the two groups (p>0.05 for all comparisons).