1.   But the attack had damaged muscle in the main pumping chamber of his heart, the left ventricle.

2.   Cheney announced Friday that tests had revealed occasional, brief episodes of ventricular tachycardia, in which the main pumping chamber of the heart beats too quickly.

3.   Excess insulin and renin can cause stiffening of the arteries and enlargement of the main pumping chamber of the heart, which have also been found in the subjects.

4.   Heart attacks had left such extensive scarring that the two main pumping chambers of his heart were failing badly, and his lungs were full of fluid.

5.   In addition, the heart muscle was scarred, and the pumping chamber was enlarged and thickened.

6.   In that condition, the main pumping chamber of the heart quivers instead of beats and loses the ability to pump blood.

7.   In that condition, the main pumping chamber of the heart quivers instead of beats, and loses the ability to pump blood.

8.   In that development, the ventricles, the main pumping chambers of the heart, beat rapidly in a chaotic, purposeless fashion.

9.   Participants also must have failure of both ventricles, the bottom pumping chambers of the heart.

10.   People who need both pumping chambers, or ventricles, replaced need a total artificial heart.