2.3.4 Heart Failure
The general term heart failure refers to any condition in which the heart fails to empty effectively.The resulting increased pressure in the venous system leads to edema，often in the lungs（pulmonary edema），and justifies the description of congestive heart failure.
The principal feature in congestive heart failure is increased intravascular volume.Congestion of the tissues results from increased arterial and venous pressure due to decreased cardiac output in the failing heart.Cardiomegaly is frequently associated with heart failure as the heart enlarges in an effort to compensate for its decreased pumping ability.
Left-sided cardiac failure occurs when the left ventricle is unable to sufficiently pump the oxygen-rich blood from the lungs to the rest of the body.This causes increased pressure in the pulmonary circulation，which results in the forcing of fluid into the pulmonary tissues—creating pulmonary edema（congestion）.The increase in pressure in the veins of the lungs results in localized fluid accumulation.The patient experiences dyspnea，cough（mostly moist sounding），fatigue，tachycardia，restlessness，and anxiety.Right-sided cardiac failure occurs when the right side of the heart is unable to sufficiently empty its blood volume and cannot accommodate all of the blood it receives from the venous circulation.This results in congestion of the viscera and the peripheral tissues.The patient experiences edema of the lower extremities（pitting edema），weight gain，enlargement of the liver（hepatomegaly），distended neck veins，ascites，anorexia，nocturia，and weakness.
Heart failure is treated with rest，drugs to strengthen heart contractions，diuretics to eliminate fluid，and restriction of salt in the diet.
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Task 6 Select the best answer according to the text.
1.Heart failure might result in all of the following conditions except________.
A.increased pressure in the venous system
B.pulmonary edema
C.cardiomegaly
D.increased cardiac output
2.The term“cardiomegaly”means________.
A.enlargement of heart
B.excision of heart
C.cardiac muscle
D.incision of heart(https://www.daowen.com)
3.The word“accommodate”probably means________.
A.pump
B.regulate
C.empty
D.have room for
4.According to the text，the congestion of the viscera and the peripheral tissues is
caused by________.
A.left-sided cardiac failure
B.right-sided cardiac failure
C.cardiomegaly
D.tachycardia
5.Diuretics can be used to________.
A.inhibit the removal of uric acid from our body
B.decrease urine output
C.increase urine output
D.treat proteinuria