A primary danger to the heart is from imbalances of minerals, such as potassium, calcium, magnesium, and phosphate, which are normally dissolved in the body's fluid. The dehydration and starvation that occurs with anorexia can reduce fluid and mineral levels and produce a condition known as electrolyte imbalance. Certain electrolytes (especially calcium and potassium) are critical for maintaining the electric currents necessary for a normal heartbeat. An imbalance in these electrolytes can be very serious and even life threatening unless fluids and minerals are replaced.
Once again you fail to simply read scripture. The passage in Kings takes place before the temple is built while the passage in Chronicles takes place many years later. (II Chronicles 9:25 is closer in time to I Kings 10:26 as is evident by the visit of the Queen of Sheba.) Moreover, there is a distinction in the two passages in that the II Chronicles 9:25 states he had 4,000 stalls for horses AND CHARIOTS. It appears that there were 10 men and 10 horses per chariot. (Compare II Sam 10:18 and I Chronicles 19:18 to see that the men of 700 chariots would be 7000 fighters.)