Why does administering a beta-1 adrenergic receptor antagonist to a patient with heart failure reduce cardiac output?

💡 Explanation

Beta-1 antagonists block norepinephrine's action on the heart, causing decreased heart rate and reduced myocardial contractility via impaired cAMP signaling; because of this reduced workload, cardiac output is diminished. Therefore, B is correct, rather than A, C, or D, which would increase cardiac output.

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