When comparing use of long term and short term therapy in patients with HFrEF a different perspective emerges. Both BB and ND CCB have negative inotropic effects which can be harmful during an acute HF exacerbation and worsen symptoms. However, BB are routinely recommended for chronic use in HFrEF due to their added neurohormonal benefit, which over time delays HF progression and reduces mortality. In contrast, long term treatment with ND CCB in those with pulmonary congestion is associated with an increased cumulative rate of cardiac events (hazard ratio 1.41). The comparative short term benefit in patients is still unclear. In a small study, patients with AF RVR and severe HF, 97% treated with IV diltiazem had a HR reduction of >20% and no evidence of HF exacerbation. A second study of patients in decompensated HF compared the use of IV metoprolol and diltiazem for control of AF RVR. Both agents were equally effective at controlling heart rate with no difference in safety endpoint or evidence of worsening heart failure. Neither of these studies specifically address compensated HFrEF.