護理師監測一位高輸出量心臟衰竭（High-output HF）病人。下列哪種狀況是其常見誘因？
A nurse is monitoring a client with high-output heart failure. Which of the following conditions is a common cause?
- ASevere anemia✓ 正解嚴重貧血
- BAortic stenosis主動脈瓣狹窄
- CHypothyroidism甲狀腺機能低下
- DMyocardial infarction心肌梗塞
高輸出量心臟衰竭（High-output Heart Failure）是指心臟功能本身正常，但因身體代謝需求過高（如甲狀腺亢進、嚴重貧血、敗血症），心臟被迫提高心輸出量（Cardiac Output）以供應組織氧氣，最終導致心臟不堪負荷而衰竭。嚴重貧血時，血液攜氧能力下降，心臟必須加速跳動並增加輸出量來彌補組織缺氧，長期下來會誘發心衰竭。此類心衰竭的特徵為心搏過速與心輸出量正常或升高，與常見因心肌受損導致的低輸出量衰竭機轉不同。
High-output heart failure occurs when the heart, although structurally normal, cannot meet the body's excessive metabolic demands (e.g., hyperthyroidism, severe anemia, sepsis). In severe anemia, the reduced oxygen-carrying capacity forces the heart to increase rate and stroke volume to maintain tissue oxygenation. Over time, this compensatory hyperdynamic state can lead to heart failure. Characteristics include tachycardia and a normal or elevated cardiac output, in contrast to low-output failure from myocardial damage.